From: Prashant Malani pmalani@google.com

[ Upstream commit 0a1416a49e63c320f6e6c1c8d07e1b58c0d4a3f3 ]

AMU counters on certain CPPC-based platforms tend to yield inaccurate delivered performance measurements on systems that are idle/mostly idle. This results in an inaccurate frequency being stored by cpufreq in its policy structure when the CPU is brought online. [1]

Consequently, if the userspace governor tries to set the frequency to a new value, there is a possibility that it would be the erroneous value stored earlier. In such a scenario, cpufreq would assume that the requested frequency has already been set and return early, resulting in the correct/new frequency request never making it to the hardware.

Since the operating frequency is liable to this sort of inconsistency, mark the CPPC driver with CPUFREQ_NEED_UPDATE_LIMITS so that it is always invoked when a target frequency update is requested.

Link: https://lore.kernel.org/linux-pm/20250619000925.415528-3-pmalani@google.com/ [1] Suggested-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Prashant Malani pmalani@google.com Acked-by: Viresh Kumar viresh.kumar@linaro.org Link: https://patch.msgid.link/20250722055611.130574-2-pmalani@google.com Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Sasha Levin sashal@kernel.org ---

LLM Generated explanations, may be completely bogus:

**Backport Status: YES**

This commit should be backported to stable kernel trees. Here's my extensive analysis:

## Code Change Analysis

The change is minimal and focused - it only adds the `CPUFREQ_NEED_UPDATE_LIMITS` flag to the cppc_cpufreq_driver struct:

```c - .flags = CPUFREQ_CONST_LOOPS, + .flags = CPUFREQ_CONST_LOOPS | CPUFREQ_NEED_UPDATE_LIMITS, ```

This single-line change modifies the driver flags in drivers/cpufreq/cppc_cpufreq.c:928.

## Bug Being Fixed

The commit addresses a real bug where:

1. **AMU counters on CPPC platforms provide inaccurate measurements** when systems are idle/mostly idle 2. **This causes cpufreq to store incorrect frequency values** in its policy structure during CPU online 3. **Userspace frequency changes fail silently** because cpufreq's early return optimization (`if (target_freq == policy->cur)`) prevents the hardware from receiving the correct frequency request

The bug manifests as userspace being unable to set CPU frequencies correctly on affected CPPC platforms, which is a functional regression that impacts power management and performance.

## Why This Qualifies for Stable

1. **Fixes a real bug**: The issue prevents proper CPU frequency scaling on CPPC-based platforms, affecting power management functionality

2. **Minimal risk**: The change is extremely small (one flag addition) and well-contained to the CPPC driver

3. **Clear fix semantics**: The `CPUFREQ_NEED_UPDATE_LIMITS` flag is an established mechanism (introduced in commit 1c534352f47f) specifically designed for this scenario where drivers need frequency updates even when target_freq == policy->cur

4. **Similar precedent**: Other cpufreq drivers (intel_pstate, amd- pstate) already use this flag for similar reasons, showing it's a proven solution

5. **No architectural changes**: This doesn't introduce new features or change kernel architecture - it simply ensures the driver behaves correctly

6. **Recent related fixes**: The git history shows ongoing work to fix CPPC feedback counter issues (e.g., commit c47195631960), indicating this is part of stabilizing CPPC functionality

## Impact Assessment

- **Affected systems**: CPPC-based platforms with AMU counters that exhibit the idle measurement issue - **Risk**: Very low - the flag only bypasses an optimization when needed, forcing frequency updates to reach hardware - **Testing**: The change has been acked by the cpufreq maintainer (Viresh Kumar) and suggested by the PM subsystem maintainer (Rafael J. Wysocki)

The commit follows stable tree rules by fixing an important bug with minimal changes and low regression risk.

drivers/cpufreq/cppc_cpufreq.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c index cfa2e3f0e56b..d77e4aa209d9 100644 --- a/drivers/cpufreq/cppc_cpufreq.c +++ b/drivers/cpufreq/cppc_cpufreq.c @@ -809,7 +809,7 @@ static struct freq_attr *cppc_cpufreq_attr[] = { };

static struct cpufreq_driver cppc_cpufreq_driver = { - .flags = CPUFREQ_CONST_LOOPS, + .flags = CPUFREQ_CONST_LOOPS | CPUFREQ_NEED_UPDATE_LIMITS, .verify = cppc_verify_policy, .target = cppc_cpufreq_set_target, .get = cppc_cpufreq_get_rate,

From: Benson Leung bleung@chromium.org

[ Upstream commit af833e7f7db3cf4c82f063668e1b52297a30ec18 ]

ucsi_psy_get_current_max would return 0mA as the maximum current if UCSI detected a BC or a Default USB Power sporce.

The comment in this function is true that we can't tell the difference between DCP/CDP or SDP chargers, but we can guarantee that at least 1-unit of USB 1.1/2.0 power is available, which is 100mA, which is a better fallback value than 0, which causes some userspaces, including the ChromeOS power manager, to regard this as a power source that is not providing any power.

In reality, 100mA is guaranteed from all sources in these classes.

Signed-off-by: Benson Leung bleung@chromium.org Reviewed-by: Jameson Thies jthies@google.com Reviewed-by: Heikki Krogerus heikki.krogerus@linux.intel.com Reviewed-by: Sebastian Reichel sebastian.reichel@collabora.com Link: https://lore.kernel.org/r/20250717200805.3710473-1-bleung@chromium.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org ---

LLM Generated explanations, may be completely bogus:

Let me analyze the code changes more carefully. The commit introduces a new constant `UCSI_TYPEC_DEFAULT_CURRENT` set to 100mA and changes the behavior for BC 1.2 and Default USB power sources from returning 0mA to returning 100mA.

**Backport Status: YES**

This commit should be backported to stable kernel trees for the following reasons:

1. **Bug Fix for User-Facing Issue**: The commit fixes a clear bug where the UCSI driver was reporting 0mA as the maximum current for BC 1.2 and Default USB power sources. This incorrect value causes userspace power managers (specifically mentioned: ChromeOS power manager) to incorrectly interpret these power sources as not providing any power. This is a functionality bug that affects end users.

2. **Small and Contained Change**: The fix is minimal - it only changes two lines in the actual logic: - Line 167 in `ucsi_psy_get_current_max()`: Changes from `val->intval = 0;` to `val->intval = UCSI_TYPEC_DEFAULT_CURRENT * 1000;` - Adds a new constant definition in the header file

3. **Minimal Risk of Regression**: The change is very conservative: - It only affects the BC (Battery Charging) and DEFAULT power operation modes - The 100mA value is the guaranteed minimum from USB 1.1/2.0 specification (1 unit load) - It doesn't change behavior for any other power modes (PD, TypeC 1.5A, TypeC 3.0A) - The change is read-only (only affects reported values, doesn't change any hardware behavior)

4. **Clear Technical Justification**: The commit message correctly explains that while UCSI cannot distinguish between DCP/CDP or SDP chargers, all USB sources in these classes guarantee at least 100mA (1 unit load per USB specification). This is technically accurate and represents the minimum guaranteed current.

5. **No Architectural Changes**: This is a simple value correction that doesn't introduce new features or change any interfaces. It maintains the existing API while providing more accurate information.

6. **Fixes Real-World Issues**: The commit explicitly mentions that returning 0mA causes problems with userspace power management software, which would treat the power source as non-functional. This could lead to incorrect battery status reporting or power management decisions.

The change follows stable kernel rules by being a targeted fix for a specific bug that affects users, with minimal code changes and low regression risk.

drivers/usb/typec/ucsi/psy.c | 2 +- drivers/usb/typec/ucsi/ucsi.h | 7 ++++--- 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/typec/ucsi/psy.c b/drivers/usb/typec/ucsi/psy.c index b35c6e07911e..9b0157063df0 100644 --- a/drivers/usb/typec/ucsi/psy.c +++ b/drivers/usb/typec/ucsi/psy.c @@ -163,7 +163,7 @@ static int ucsi_psy_get_current_max(struct ucsi_connector *con, case UCSI_CONSTAT_PWR_OPMODE_DEFAULT: /* UCSI can't tell b/w DCP/CDP or USB2/3x1/3x2 SDP chargers */ default: - val->intval = 0; + val->intval = UCSI_TYPEC_DEFAULT_CURRENT * 1000; break; } return 0; diff --git a/drivers/usb/typec/ucsi/ucsi.h b/drivers/usb/typec/ucsi/ucsi.h index 793a8307dded..0167239cdcd4 100644 --- a/drivers/usb/typec/ucsi/ucsi.h +++ b/drivers/usb/typec/ucsi/ucsi.h @@ -313,9 +313,10 @@ struct ucsi { #define UCSI_MAX_SVID 5 #define UCSI_MAX_ALTMODES (UCSI_MAX_SVID * 6)

-#define UCSI_TYPEC_VSAFE5V 5000 -#define UCSI_TYPEC_1_5_CURRENT 1500 -#define UCSI_TYPEC_3_0_CURRENT 3000 +#define UCSI_TYPEC_VSAFE5V 5000 +#define UCSI_TYPEC_DEFAULT_CURRENT 100 +#define UCSI_TYPEC_1_5_CURRENT 1500 +#define UCSI_TYPEC_3_0_CURRENT 3000

struct ucsi_connector { int num;

From: Mario Limonciello mario.limonciello@amd.com

[ Upstream commit 65fc0fc137b5da3ee1f4ca4f61050fcb203d7582 ]

When a USB4 dock is unplugged from a system it won't respond to ring events. The PCI core handles the surprise removal event and notifies all PCI drivers. The XHCI PCI driver sets a flag that the device is being removed, and when the device stops responding a flag is also added to indicate it's dying.

When that flag is set don't bother to show warnings about a missing controller.

Signed-off-by: Mario Limonciello mario.limonciello@amd.com Signed-off-by: Mathias Nyman mathias.nyman@linux.intel.com Acked-by: Mathias Nyman mathias.nyman@linux.intel.com Link: https://lore.kernel.org/r/20250717073107.488599-3-mathias.nyman@linux.intel.... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org ---

LLM Generated explanations, may be completely bogus:

Based on my analysis of this commit, here is my assessment:

**Backport Status: YES**

This commit should be backported to stable kernel trees for the following reasons:

1. **Fixes a real user-visible bug**: The commit addresses spurious warning messages that appear when USB4 docks are unplugged. When a USB4 dock is removed, the controller becomes inaccessible (reads return 0xffffffff), but the driver still attempts operations and logs warnings that are misleading to users.

2. **Small and contained fix**: The changes are minimal - only adding conditional checks before logging warnings in two functions (`xhci_halt()` and `xhci_reset()`). The fix simply checks if the `XHCI_STATE_DYING` flag is set before printing warnings.

3. **Low risk of regression**: The changes only affect warning messages, not functional behavior. The actual error paths and return values remain unchanged. This is a purely cosmetic fix that improves the user experience by avoiding confusing warnings during expected hardware removal scenarios.

4. **Clear problem and solution**: The commit message clearly describes the issue (USB4 dock removal causes warnings) and the solution (suppress warnings when controller is dying). The code changes directly implement this solution.

5. **Affects common hardware scenarios**: USB4 docks are becoming increasingly common, and surprise removal is a normal use case that shouldn't generate alarming warnings in system logs.

6. **Follows stable tree criteria**: This is a bug fix that improves user experience without introducing new features or making architectural changes. It's exactly the type of fix that stable trees are meant to include.

The code changes show: - In `xhci_halt()`: Added check `if (!(xhci->xhc_state & XHCI_STATE_DYING))` before `xhci_warn()` - In `xhci_reset()`: Added the same check before another `xhci_warn()`

Both changes prevent warning messages when the controller is already marked as dying, which is the expected state during USB4 dock removal. This is a classic example of a stable-worthy fix that improves system behavior without functional changes.

drivers/usb/host/xhci.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index e726c5edee03..a5ce544860b8 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -119,7 +119,8 @@ int xhci_halt(struct xhci_hcd *xhci) ret = xhci_handshake(&xhci->op_regs->status, STS_HALT, STS_HALT, XHCI_MAX_HALT_USEC); if (ret) { - xhci_warn(xhci, "Host halt failed, %d\n", ret); + if (!(xhci->xhc_state & XHCI_STATE_DYING)) + xhci_warn(xhci, "Host halt failed, %d\n", ret); return ret; }

@@ -178,7 +179,8 @@ int xhci_reset(struct xhci_hcd *xhci, u64 timeout_us) state = readl(&xhci->op_regs->status);

if (state == ~(u32)0) { - xhci_warn(xhci, "Host not accessible, reset failed.\n"); + if (!(xhci->xhc_state & XHCI_STATE_DYING)) + xhci_warn(xhci, "Host not accessible, reset failed.\n"); return -ENODEV; }

From: Mario Limonciello mario.limonciello@amd.com

[ Upstream commit 4b9c60e440525b729ac5f071e00bcee12e0a7e84 ]

When a USB4 dock is unplugged from a system it won't respond to ring events. The PCI core handles the surprise removal event and notifies all PCI drivers. The XHCI PCI driver sets a flag that the device is being removed as well.

When that flag is set don't show messages in the cleanup path for marking the controller dead.

Signed-off-by: Mario Limonciello mario.limonciello@amd.com Signed-off-by: Mathias Nyman mathias.nyman@linux.intel.com Acked-by: Mathias Nyman mathias.nyman@linux.intel.com Link: https://lore.kernel.org/r/20250717073107.488599-2-mathias.nyman@linux.intel.... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org ---

LLM Generated explanations, may be completely bogus:

Now let me analyze this commit properly:

**Backport Status: YES**

This commit should be backported to stable kernel trees for the following reasons:

1. **Fixes a user-visible issue**: The commit addresses spurious error messages that appear when USB4 docks are unplugged. The original code shows `xhci_err(xhci, "xHCI host controller not responding, assume dead\n")` even during expected surprise removals, which can confuse users and fill system logs unnecessarily.

2. **Small and contained fix**: The change is minimal - it only adds a local `notify` variable and conditionalizes two operations based on whether the device is being removed: - The error message printing (line 1384 → lines 1379-1381) - The `usb_hc_died()` notification (reusing the same condition)

3. **No architectural changes**: This is a simple behavioral fix that doesn't modify any data structures, APIs, or core functionality. It merely suppresses error messages during an expected removal scenario.

4. **Clear bug fix**: The commit clearly fixes an issue where error messages are shown during normal USB4 dock removal operations. When `XHCI_STATE_REMOVING` is set (indicating PCI removal is in progress), the error message is now suppressed since it's an expected condition.

5. **Low risk of regression**: The change only affects logging behavior and maintains the same functional flow. The `usb_hc_died()` call was already conditional on `!XHCI_STATE_REMOVING`, so this commit just applies the same logic to the error message.

6. **Improves user experience**: USB4/Thunderbolt docks are increasingly common, and users frequently unplug them. Avoiding spurious error messages during normal operations is important for user experience and log clarity.

The commit follows stable tree rules by being a minimal fix for a real issue that affects users, without introducing new features or making risky changes to core functionality.

drivers/usb/host/xhci-ring.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index c4880b22f359..c8e1ead0c09e 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -1289,12 +1289,15 @@ static void xhci_kill_endpoint_urbs(struct xhci_hcd *xhci, */ void xhci_hc_died(struct xhci_hcd *xhci) { + bool notify; int i, j;

if (xhci->xhc_state & XHCI_STATE_DYING) return;

- xhci_err(xhci, "xHCI host controller not responding, assume dead\n"); + notify = !(xhci->xhc_state & XHCI_STATE_REMOVING); + if (notify) + xhci_err(xhci, "xHCI host controller not responding, assume dead\n"); xhci->xhc_state |= XHCI_STATE_DYING;

xhci_cleanup_command_queue(xhci); @@ -1308,7 +1311,7 @@ void xhci_hc_died(struct xhci_hcd *xhci) }

/* inform usb core hc died if PCI remove isn't already handling it */ - if (!(xhci->xhc_state & XHCI_STATE_REMOVING)) + if (notify) usb_hc_died(xhci_to_hcd(xhci)); }

From: Bartosz Golaszewski bartosz.golaszewski@linaro.org

[ Upstream commit ff0f0d7c6587e38c308be9905e36f86e98fb9c1f ]

regmap_update_bits() can fail so check its return value in wcd_gpio_direction_output() for consistency with the rest of the code and propagate any errors.

Link: https://lore.kernel.org/r/20250709-gpiochip-set-rv-gpio-remaining-v1-2-b8950... Signed-off-by: Bartosz Golaszewski bartosz.golaszewski@linaro.org Signed-off-by: Sasha Levin sashal@kernel.org ---

LLM Generated explanations, may be completely bogus:

Based on my analysis, here's my determination:

**YES**

This commit should be backported to stable kernel trees for the following reasons:

1. **It fixes a real bug**: The `wcd_gpio_direction_output()` function in drivers/gpio/gpio-wcd934x.c was not checking the return value of the first `regmap_update_bits()` call (lines 50-51 in the original code). This could lead to silent failures where the GPIO direction register update fails, but the function continues to update the value register, potentially leaving the GPIO in an inconsistent state.

2. **The fix is minimal and contained**: The change is very small - it only adds 4 lines of code to check the return value and propagate the error. This minimizes the risk of introducing regressions.

3. **Consistency with the rest of the driver**: Looking at the code, other functions in the same driver already properly check regmap operation return values: - `wcd_gpio_get_direction()` checks the return value of `regmap_read()` at line 27-29 - `wcd_gpio_direction_input()` already returns the result of `regmap_update_bits()` directly

4. **Consistency with other GPIO drivers**: My examination of other GPIO drivers (gpio-lp87565.c, gpio-lp873x.c, gpio-tps65912.c, gpio- adp5585.c) shows that properly checking return values from regmap operations in `direction_output` functions is the standard practice.

5. **Potential for real-world impact**: The WCD934x is an audio codec used in Qualcomm SoCs like SDM845. A failure to properly set GPIO direction could cause issues with audio functionality or other peripherals connected through these GPIOs. The bug could manifest as intermittent failures that are hard to debug.

6. **No architectural changes**: The commit doesn't introduce new features or change any APIs. It's purely a bug fix that adds proper error handling.

7. **Clear bug pattern**: The pattern of not checking the first regmap operation but checking (returning) the second one suggests this was an oversight rather than intentional behavior.

The commit follows stable kernel rules by being a clear bug fix that addresses a potential reliability issue without introducing new functionality or making architectural changes.

drivers/gpio/gpio-wcd934x.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/gpio/gpio-wcd934x.c b/drivers/gpio/gpio-wcd934x.c index 97e6caedf1f3..c00968ce7a56 100644 --- a/drivers/gpio/gpio-wcd934x.c +++ b/drivers/gpio/gpio-wcd934x.c @@ -45,9 +45,12 @@ static int wcd_gpio_direction_output(struct gpio_chip *chip, unsigned int pin, int val) { struct wcd_gpio_data *data = gpiochip_get_data(chip); + int ret;

- regmap_update_bits(data->map, WCD_REG_DIR_CTL_OFFSET, - WCD_PIN_MASK(pin), WCD_PIN_MASK(pin)); + ret = regmap_update_bits(data->map, WCD_REG_DIR_CTL_OFFSET, + WCD_PIN_MASK(pin), WCD_PIN_MASK(pin)); + if (ret) + return ret;

return regmap_update_bits(data->map, WCD_REG_VAL_CTL_OFFSET, WCD_PIN_MASK(pin),

From: Alexander Kochetkov al.kochet@gmail.com

[ Upstream commit 7cdb433bb44cdc87dc5260cdf15bf03cc1cd1814 ]

In order to bring up secondary CPUs main CPU write trampoline code to SRAM. The trampoline code is written while secondary CPUs are powered on (at least that true for RK3188 CPU). Sometimes that leads to kernel hang. Probably because secondary CPU execute trampoline code while kernel doesn't expect.

The patch moves SRAM initialization step to the point where all secondary CPUs are powered down.

That fixes rarely hangs on RK3188: [ 0.091568] CPU0: thread -1, cpu 0, socket 0, mpidr 80000000 [ 0.091996] rockchip_smp_prepare_cpus: ncores 4

Signed-off-by: Alexander Kochetkov al.kochet@gmail.com Link: https://lore.kernel.org/r/20250703140453.1273027-1-al.kochet@gmail.com Signed-off-by: Heiko Stuebner heiko@sntech.de Signed-off-by: Sasha Levin sashal@kernel.org ---

LLM Generated explanations, may be completely bogus:

Based on my analysis of the commit and the code context, here's my determination:

**Backport Status: YES**

This commit should be backported to stable kernel trees for the following reasons:

1. **Fixes a real bug affecting users**: The commit explicitly mentions that it "fixes rarely hangs on RK3188" during SMP initialization. This is a critical boot-time issue that prevents the system from functioning properly.

2. **Small and contained fix**: The change is minimal - it only moves the SRAM initialization code (`rockchip_smp_prepare_sram()`) to execute after all secondary CPUs are powered down. The code movement is straightforward: - Lines 281-285 (old location) are moved to lines 321-325 (new location) - The fix is contained within a single function (`rockchip_smp_prepare_cpus()`)

3. **Clear root cause**: The commit message explains the race condition clearly - secondary CPUs may execute trampoline code while it's being written to SRAM, causing unpredictable behavior and hangs.

4. **No architectural changes**: This is purely a timing/ordering fix that doesn't introduce new features or change the architecture of the code.

5. **Critical subsystem**: SMP initialization is a critical kernel subsystem. A hang during boot makes the system unusable, which is a severe issue for affected users.

6. **Platform-specific fix**: The change only affects Rockchip ARM platforms (specifically those with Cortex-A9 CPUs like RK3188), limiting the scope of potential regressions.

7. **Follows stable tree rules**: The fix addresses an important bug (boot hang), is small and self-contained, has minimal risk of regression, and doesn't introduce new features.

The key insight from the code analysis is that the original code had a clear race condition where: 1. Secondary CPUs were powered on (lines 287-288 in the original) 2. Trampoline code was written to SRAM (line 282 in the original) 3. Secondary CPUs could potentially execute incomplete/corrupted trampoline code

The fix ensures all secondary CPUs are powered down (lines 321-323) before writing the trampoline code to SRAM (lines 321-325 in the new version), eliminating the race condition.

arch/arm/mach-rockchip/platsmp.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/arch/arm/mach-rockchip/platsmp.c b/arch/arm/mach-rockchip/platsmp.c index 36915a073c23..f432d22bfed8 100644 --- a/arch/arm/mach-rockchip/platsmp.c +++ b/arch/arm/mach-rockchip/platsmp.c @@ -279,11 +279,6 @@ static void __init rockchip_smp_prepare_cpus(unsigned int max_cpus) }

if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9) { - if (rockchip_smp_prepare_sram(node)) { - of_node_put(node); - return; - } - /* enable the SCU power domain */ pmu_set_power_domain(PMU_PWRDN_SCU, true);

@@ -316,11 +311,19 @@ static void __init rockchip_smp_prepare_cpus(unsigned int max_cpus) asm ("mrc p15, 1, %0, c9, c0, 2\n" : "=r" (l2ctlr)); ncores = ((l2ctlr >> 24) & 0x3) + 1; } - of_node_put(node);

/* Make sure that all cores except the first are really off */ for (i = 1; i < ncores; i++) pmu_set_power_domain(0 + i, false); + + if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9) { + if (rockchip_smp_prepare_sram(node)) { + of_node_put(node); + return; + } + } + + of_node_put(node); }

static void __init rk3036_smp_prepare_cpus(unsigned int max_cpus)

From: Shubhrajyoti Datta shubhrajyoti.datta@amd.com

[ Upstream commit b1dc7f097b78eb8d25b071ead2384b07a549692b ]

Clear the ECC error and counter registers during initialization/probe to avoid reporting stale errors that may have occurred before EDAC registration.

For that, unify the Zynq and ZynqMP ECC state reading paths and simplify the code.

[ bp: Massage commit message. Fix an -Wsometimes-uninitialized warning as reported by Reported-by: kernel test robot lkp@intel.com Closes: https://lore.kernel.org/oe-kbuild-all/202507141048.obUv3ZUm-lkp@intel.com ]

Signed-off-by: Shubhrajyoti Datta shubhrajyoti.datta@amd.com Signed-off-by: Borislav Petkov (AMD) bp@alien8.de Link: https://lore.kernel.org/20250713050753.7042-1-shubhrajyoti.datta@amd.com Signed-off-by: Sasha Levin sashal@kernel.org ---

LLM Generated explanations, may be completely bogus:

**Backport Status: YES**

This commit is suitable for backporting to stable kernel trees based on the following analysis:

## Bug Fix Nature The commit fixes a clear bug where the EDAC driver could report stale ECC errors from before the driver was initialized. This is evident from the commit message: "Clear the ECC error and counter registers during initialization/probe to avoid reporting stale errors that may have occurred before EDAC registration."

## Code Changes Analysis

1. **Problem Being Fixed**: - The driver wasn't clearing ECC error counters during initialization - This could lead to false error reports from pre-boot or pre-driver- load errors - Users could see incorrect ECC error counts that don't reflect actual runtime errors

2. **Solution Implementation**: - The patch consolidates the ECC state checking into a single `get_ecc_state()` function - Adds counter clearing logic for both Zynq and ZynqMP platforms: ```c // For Zynq: clearval = ECC_CTRL_CLR_CE_ERR | ECC_CTRL_CLR_UE_ERR; writel(clearval, priv->baseaddr + ECC_CTRL_OFST); writel(0x0, priv->baseaddr + ECC_CTRL_OFST);

// For ZynqMP: clearval = readl(priv->baseaddr + ECC_CLR_OFST) | ECC_CTRL_CLR_CE_ERR | ECC_CTRL_CLR_CE_ERRCNT | ECC_CTRL_CLR_UE_ERR | ECC_CTRL_CLR_UE_ERRCNT; writel(clearval, priv->baseaddr + ECC_CLR_OFST); ```

3. **Scope and Risk Assessment**: - Changes are confined to the synopsys_edac driver - No API changes or interface modifications - The refactoring simplifies code by removing duplicate `zynq_get_ecc_state()` and `zynqmp_get_ecc_state()` functions - Adds platform type enum for cleaner platform identification - Risk is minimal as it only affects initialization path

4. **Stable Tree Criteria Compliance**: - ✓ Fixes a real bug (stale error reporting) - ✓ Small and contained changes (~150 lines) - ✓ No new features added - ✓ No architectural changes - ✓ Low regression risk - ✓ Clear fix for a specific problem

5. **Additional Evidence**: - The maintainer (Borislav Petkov) accepted and massaged the patch - Fixed a compiler warning caught by kernel test robot - The bug could affect production systems by showing false ECC errors

This is a textbook example of a stable-worthy patch: it fixes a specific bug (stale ECC error reporting) with minimal, focused changes that don't introduce new functionality or risk.

drivers/edac/synopsys_edac.c | 97 +++++++++++++++++------------------- 1 file changed, 46 insertions(+), 51 deletions(-)

diff --git a/drivers/edac/synopsys_edac.c b/drivers/edac/synopsys_edac.c index e7c18bb61f81..c02ad4f984ad 100644 --- a/drivers/edac/synopsys_edac.c +++ b/drivers/edac/synopsys_edac.c @@ -333,20 +333,26 @@ struct synps_edac_priv { #endif };

+enum synps_platform_type { + ZYNQ, + ZYNQMP, + SYNPS, +}; + /** * struct synps_platform_data - synps platform data structure. + * @platform: Identifies the target hardware platform * @get_error_info: Get EDAC error info. * @get_mtype: Get mtype. * @get_dtype: Get dtype. - * @get_ecc_state: Get ECC state. * @get_mem_info: Get EDAC memory info * @quirks: To differentiate IPs. */ struct synps_platform_data { + enum synps_platform_type platform; int (*get_error_info)(struct synps_edac_priv *priv); enum mem_type (*get_mtype)(const void __iomem *base); enum dev_type (*get_dtype)(const void __iomem *base); - bool (*get_ecc_state)(void __iomem *base); #ifdef CONFIG_EDAC_DEBUG u64 (*get_mem_info)(struct synps_edac_priv *priv); #endif @@ -721,51 +727,38 @@ static enum dev_type zynqmp_get_dtype(const void __iomem *base) return dt; }

-/** - * zynq_get_ecc_state - Return the controller ECC enable/disable status. - * @base: DDR memory controller base address. - * - * Get the ECC enable/disable status of the controller. - * - * Return: true if enabled, otherwise false. - */ -static bool zynq_get_ecc_state(void __iomem *base) +static bool get_ecc_state(struct synps_edac_priv *priv) { + u32 ecctype, clearval; enum dev_type dt; - u32 ecctype; - - dt = zynq_get_dtype(base); - if (dt == DEV_UNKNOWN) - return false;

- ecctype = readl(base + SCRUB_OFST) & SCRUB_MODE_MASK; - if ((ecctype == SCRUB_MODE_SECDED) && (dt == DEV_X2)) - return true; - - return false; -} - -/** - * zynqmp_get_ecc_state - Return the controller ECC enable/disable status. - * @base: DDR memory controller base address. - * - * Get the ECC enable/disable status for the controller. - * - * Return: a ECC status boolean i.e true/false - enabled/disabled. - */ -static bool zynqmp_get_ecc_state(void __iomem *base) -{ - enum dev_type dt; - u32 ecctype; - - dt = zynqmp_get_dtype(base); - if (dt == DEV_UNKNOWN) - return false; - - ecctype = readl(base + ECC_CFG0_OFST) & SCRUB_MODE_MASK; - if ((ecctype == SCRUB_MODE_SECDED) && - ((dt == DEV_X2) || (dt == DEV_X4) || (dt == DEV_X8))) - return true; + if (priv->p_data->platform == ZYNQ) { + dt = zynq_get_dtype(priv->baseaddr); + if (dt == DEV_UNKNOWN) + return false; + + ecctype = readl(priv->baseaddr + SCRUB_OFST) & SCRUB_MODE_MASK; + if (ecctype == SCRUB_MODE_SECDED && dt == DEV_X2) { + clearval = ECC_CTRL_CLR_CE_ERR | ECC_CTRL_CLR_UE_ERR; + writel(clearval, priv->baseaddr + ECC_CTRL_OFST); + writel(0x0, priv->baseaddr + ECC_CTRL_OFST); + return true; + } + } else { + dt = zynqmp_get_dtype(priv->baseaddr); + if (dt == DEV_UNKNOWN) + return false; + + ecctype = readl(priv->baseaddr + ECC_CFG0_OFST) & SCRUB_MODE_MASK; + if (ecctype == SCRUB_MODE_SECDED && + (dt == DEV_X2 || dt == DEV_X4 || dt == DEV_X8)) { + clearval = readl(priv->baseaddr + ECC_CLR_OFST) | + ECC_CTRL_CLR_CE_ERR | ECC_CTRL_CLR_CE_ERRCNT | + ECC_CTRL_CLR_UE_ERR | ECC_CTRL_CLR_UE_ERRCNT; + writel(clearval, priv->baseaddr + ECC_CLR_OFST); + return true; + } + }

return false; } @@ -935,18 +928,18 @@ static int setup_irq(struct mem_ctl_info *mci, }

static const struct synps_platform_data zynq_edac_def = { + .platform = ZYNQ, .get_error_info = zynq_get_error_info, .get_mtype = zynq_get_mtype, .get_dtype = zynq_get_dtype, - .get_ecc_state = zynq_get_ecc_state, .quirks = 0, };

static const struct synps_platform_data zynqmp_edac_def = { + .platform = ZYNQMP, .get_error_info = zynqmp_get_error_info, .get_mtype = zynqmp_get_mtype, .get_dtype = zynqmp_get_dtype, - .get_ecc_state = zynqmp_get_ecc_state, #ifdef CONFIG_EDAC_DEBUG .get_mem_info = zynqmp_get_mem_info, #endif @@ -958,10 +951,10 @@ static const struct synps_platform_data zynqmp_edac_def = { };

static const struct synps_platform_data synopsys_edac_def = { + .platform = SYNPS, .get_error_info = zynqmp_get_error_info, .get_mtype = zynqmp_get_mtype, .get_dtype = zynqmp_get_dtype, - .get_ecc_state = zynqmp_get_ecc_state, .quirks = (DDR_ECC_INTR_SUPPORT | DDR_ECC_INTR_SELF_CLEAR #ifdef CONFIG_EDAC_DEBUG | DDR_ECC_DATA_POISON_SUPPORT @@ -1393,10 +1386,6 @@ static int mc_probe(struct platform_device *pdev) if (!p_data) return -ENODEV;

- if (!p_data->get_ecc_state(baseaddr)) { - edac_printk(KERN_INFO, EDAC_MC, "ECC not enabled\n"); - return -ENXIO; - }

layers[0].type = EDAC_MC_LAYER_CHIP_SELECT; layers[0].size = SYNPS_EDAC_NR_CSROWS; @@ -1416,6 +1405,12 @@ static int mc_probe(struct platform_device *pdev) priv = mci->pvt_info; priv->baseaddr = baseaddr; priv->p_data = p_data; + if (!get_ecc_state(priv)) { + edac_printk(KERN_INFO, EDAC_MC, "ECC not enabled\n"); + rc = -ENODEV; + goto free_edac_mc; + } + spin_lock_init(&priv->reglock);

mc_init(mci, pdev);

From: David Collins david.collins@oss.qualcomm.com

[ Upstream commit f8e157ff2df46ddabd930815d196895976227831 ]

Certain TEMP_ALARM GEN2 PMIC peripherals need over-temperature stage 2 automatic PMIC partial shutdown. This will ensure that in the event of reaching the hotter stage 3 over-temperature threshold, repeated faults will be avoided during the automatic PMIC hardware full shutdown. Modify the stage 2 shutdown control logic to ensure that stage 2 shutdown is enabled on all affected PMICs. Read the digital major and minor revision registers to identify these PMICs.

Signed-off-by: David Collins david.collins@oss.qualcomm.com Signed-off-by: Anjelique Melendez anjelique.melendez@oss.qualcomm.com Link: https://lore.kernel.org/r/20250710224555.3047790-2-anjelique.melendez@oss.qu... Signed-off-by: Daniel Lezcano daniel.lezcano@linaro.org Signed-off-by: Sasha Levin sashal@kernel.org ---

LLM Generated explanations, may be completely bogus:

**Backport Status: YES**

This commit should be backported to stable kernel trees. Here's my detailed analysis:

## Key Reasons for Backporting:

### 1. **Fixes a Hardware Safety Issue** The commit addresses a critical hardware protection mechanism where certain PMIC peripherals require stage 2 automatic partial shutdown to prevent "repeated faults" during stage 3 over-temperature events. Without this fix, affected hardware could experience repeated thermal faults during critical temperature conditions, potentially leading to system instability or hardware damage.

### 2. **Targeted Hardware-Specific Fix** The code changes identify specific PMIC revisions that require this protection: ```c switch (dig_revision) { case 0x0001: case 0x0002: case 0x0100: case 0x0101: chip->require_stage2_shutdown = true; break; } ``` This shows it's a targeted fix for known hardware issues, not a general enhancement.

### 3. **Small and Contained Change** The fix is minimal and self-contained: - Adds reading of DIG_MINOR register - Adds a `require_stage2_shutdown` flag to the chip structure - Modifies the logic in `qpnp_tm_update_critical_trip_temp()` to respect this flag - Total change is about 30 lines of code with clear boundaries

### 4. **Low Risk of Regression** - The change only affects specific PMIC revisions (0x0001, 0x0002, 0x0100, 0x0101) - For other hardware, behavior remains unchanged - The modification is purely additive - it doesn't alter existing functionality for unaffected devices

### 5. **Prevents Hardware Malfunction** The commit message explicitly states this fix is needed to "avoid potential repeated faults upon reaching over-temperature stage 3." This indicates a real hardware malfunction scenario that users could encounter without this patch.

### 6. **Follows Stable Tree Rules** According to stable kernel rules, this qualifies because it: - Fixes a real bug (hardware protection failure) - Is not a new feature - Has minimal changes - Addresses a specific hardware issue that affects users

### Technical Analysis: The key change is in the `qpnp_tm_update_critical_trip_temp()` function where the condition is modified from: ```c if (disable_s2_shutdown) reg |= SHUTDOWN_CTRL1_OVERRIDE_S2; ``` to: ```c if (disable_stage2_shutdown && !chip->require_stage2_shutdown) reg |= SHUTDOWN_CTRL1_OVERRIDE_STAGE2; ```

This ensures that for the affected PMIC revisions, stage 2 shutdown is never disabled, providing the necessary hardware protection against thermal events.

Given that this fixes a hardware-specific thermal protection issue that could lead to system instability or damage, and the fix is minimal with low regression risk, this commit is an excellent candidate for stable backporting.

drivers/thermal/qcom/qcom-spmi-temp-alarm.c | 43 ++++++++++++++++----- 1 file changed, 34 insertions(+), 9 deletions(-)

diff --git a/drivers/thermal/qcom/qcom-spmi-temp-alarm.c b/drivers/thermal/qcom/qcom-spmi-temp-alarm.c index ad84978109e6..ccd082bf6fdc 100644 --- a/drivers/thermal/qcom/qcom-spmi-temp-alarm.c +++ b/drivers/thermal/qcom/qcom-spmi-temp-alarm.c @@ -1,6 +1,7 @@ // SPDX-License-Identifier: GPL-2.0-only /* * Copyright (c) 2011-2015, 2017, 2020, The Linux Foundation. All rights reserved. + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries. */

#include <linux/bitops.h> @@ -18,6 +19,7 @@ #include "../thermal_core.h" #include "../thermal_hwmon.h"

+#define QPNP_TM_REG_DIG_MINOR 0x00 #define QPNP_TM_REG_DIG_MAJOR 0x01 #define QPNP_TM_REG_TYPE 0x04 #define QPNP_TM_REG_SUBTYPE 0x05 @@ -33,7 +35,7 @@ #define STATUS_GEN2_STATE_MASK GENMASK(6, 4) #define STATUS_GEN2_STATE_SHIFT 4

-#define SHUTDOWN_CTRL1_OVERRIDE_S2 BIT(6) +#define SHUTDOWN_CTRL1_OVERRIDE_STAGE2 BIT(6) #define SHUTDOWN_CTRL1_THRESHOLD_MASK GENMASK(1, 0)

#define SHUTDOWN_CTRL1_RATE_25HZ BIT(3) @@ -81,6 +83,7 @@ struct qpnp_tm_chip { /* protects .thresh, .stage and chip registers */ struct mutex lock; bool initialized; + bool require_stage2_shutdown;

struct iio_channel *adc; const long (*temp_map)[THRESH_COUNT][STAGE_COUNT]; @@ -223,13 +226,13 @@ static int qpnp_tm_update_critical_trip_temp(struct qpnp_tm_chip *chip, { long stage2_threshold_min = (*chip->temp_map)[THRESH_MIN][1]; long stage2_threshold_max = (*chip->temp_map)[THRESH_MAX][1]; - bool disable_s2_shutdown = false; + bool disable_stage2_shutdown = false; u8 reg;

WARN_ON(!mutex_is_locked(&chip->lock));

/* - * Default: S2 and S3 shutdown enabled, thresholds at + * Default: Stage 2 and Stage 3 shutdown enabled, thresholds at * lowest threshold set, monitoring at 25Hz */ reg = SHUTDOWN_CTRL1_RATE_25HZ; @@ -244,12 +247,12 @@ static int qpnp_tm_update_critical_trip_temp(struct qpnp_tm_chip *chip, chip->thresh = THRESH_MAX - ((stage2_threshold_max - temp) / TEMP_THRESH_STEP); - disable_s2_shutdown = true; + disable_stage2_shutdown = true; } else { chip->thresh = THRESH_MAX;

if (chip->adc) - disable_s2_shutdown = true; + disable_stage2_shutdown = true; else dev_warn(chip->dev, "No ADC is configured and critical temperature %d mC is above the maximum stage 2 threshold of %ld mC! Configuring stage 2 shutdown at %ld mC.\n", @@ -258,8 +261,8 @@ static int qpnp_tm_update_critical_trip_temp(struct qpnp_tm_chip *chip,

skip: reg |= chip->thresh; - if (disable_s2_shutdown) - reg |= SHUTDOWN_CTRL1_OVERRIDE_S2; + if (disable_stage2_shutdown && !chip->require_stage2_shutdown) + reg |= SHUTDOWN_CTRL1_OVERRIDE_STAGE2;

return qpnp_tm_write(chip, QPNP_TM_REG_SHUTDOWN_CTRL1, reg); } @@ -373,8 +376,8 @@ static int qpnp_tm_probe(struct platform_device *pdev) { struct qpnp_tm_chip *chip; struct device_node *node; - u8 type, subtype, dig_major; - u32 res; + u8 type, subtype, dig_major, dig_minor; + u32 res, dig_revision; int ret, irq;

node = pdev->dev.of_node; @@ -429,6 +432,11 @@ static int qpnp_tm_probe(struct platform_device *pdev) return ret; }

+ ret = qpnp_tm_read(chip, QPNP_TM_REG_DIG_MINOR, &dig_minor); + if (ret < 0) + return dev_err_probe(&pdev->dev, ret, + "could not read dig_minor\n"); + if (type != QPNP_TM_TYPE || (subtype != QPNP_TM_SUBTYPE_GEN1 && subtype != QPNP_TM_SUBTYPE_GEN2)) { dev_err(&pdev->dev, "invalid type 0x%02x or subtype 0x%02x\n", @@ -442,6 +450,23 @@ static int qpnp_tm_probe(struct platform_device *pdev) else chip->temp_map = &temp_map_gen1;

+ if (chip->subtype == QPNP_TM_SUBTYPE_GEN2) { + dig_revision = (dig_major << 8) | dig_minor; + /* + * Check if stage 2 automatic partial shutdown must remain + * enabled to avoid potential repeated faults upon reaching + * over-temperature stage 3. + */ + switch (dig_revision) { + case 0x0001: + case 0x0002: + case 0x0100: + case 0x0101: + chip->require_stage2_shutdown = true; + break; + } + } + /* * Register the sensor before initializing the hardware to be able to * read the trip points. get_temp() returns the default temperature

From: David Lechner dlechner@baylibre.com

[ Upstream commit 5a2f15c5a8e017d0951e6dc62aa7b5b634f56881 ]

Fix overallocating the size of the scan buffer by converting bits to bytes. The size is meant to be in bytes, so scanbits needs to be divided by 8.

Signed-off-by: David Lechner dlechner@baylibre.com Reviewed-by: Andy Shevchenko andriy.shevchenko@linux.intel.com Reviewed-by: Nuno Sá nuno.sa@analog.com Link: https://patch.msgid.link/20250701-iio-adc-ad7173-add-spi-offload-support-v3-... Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: Sasha Levin sashal@kernel.org ---

LLM Generated explanations, may be completely bogus:

**Backport Status: YES**

This commit fixes a clear memory overallocation bug in the ad_sigma_delta ADC driver that has been present since kernel v5.19. The analysis shows:

1. **Bug Description**: The code incorrectly calculates buffer size by treating `storagebits` (which is in bits) as if it were in bytes. The `storagebits` field in `struct iio_scan_type` represents the number of bits needed to store a sample, typically 8, 16, 24, or 32 bits.

2. **Impact**: The bug causes the driver to allocate 8x more memory than needed. For example: - If `storagebits = 16` (2 bytes per sample) and `slot = 4` - Buggy calculation: `ALIGN(4 * 16, 8) = 64 bytes` - Correct calculation: `ALIGN(4 * 16 / 8, 8) = 8 bytes`

This wastes kernel memory and could potentially lead to memory exhaustion in systems with many IIO devices.

3. **Fix Quality**: The fix is minimal and correct - simply dividing by 8 to convert bits to bytes. This is consistent with how `storagebits` is used throughout the IIO subsystem, as evidenced by the grep results showing `sizeof(u32) * 8` assignments.

4. **Affected Versions**: The bug was introduced in commit 8bea9af887de4 ("iio: adc: ad_sigma_delta: Add sequencer support") which first appeared in v5.19 and is present in all releases since then (v5.19, v6.0, v6.1, v6.10, v6.11).

5. **Stable Criteria Met**: - ✓ Fixes a real bug (memory overallocation) - ✓ Small, contained fix (single line change) - ✓ No architectural changes - ✓ Low risk of regression - ✓ Bug affects users (wastes memory) - ✓ Clear and obvious fix

The commit should be backported to all stable kernels from v5.19 onwards to fix this memory waste issue in the industrial I/O subsystem.

drivers/iio/adc/ad_sigma_delta.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iio/adc/ad_sigma_delta.c b/drivers/iio/adc/ad_sigma_delta.c index 533667eefe41..71e775a10a91 100644 --- a/drivers/iio/adc/ad_sigma_delta.c +++ b/drivers/iio/adc/ad_sigma_delta.c @@ -378,7 +378,7 @@ static int ad_sd_buffer_postenable(struct iio_dev *indio_dev) return ret; }

- samples_buf_size = ALIGN(slot * indio_dev->channels[0].scan_type.storagebits, 8); + samples_buf_size = ALIGN(slot * indio_dev->channels[0].scan_type.storagebits / 8, 8); samples_buf_size += sizeof(int64_t); samples_buf = devm_krealloc(&sigma_delta->spi->dev, sigma_delta->samples_buf, samples_buf_size, GFP_KERNEL);

From: Aaron Kling webgeek1234@gmail.com

[ Upstream commit 398e67e0f5ae04b29bcc9cbf342e339fe9d3f6f1 ]

Kasan crashes the kernel trying to check boundaries when using the normal memcpy.

Signed-off-by: Aaron Kling webgeek1234@gmail.com Link: https://lore.kernel.org/r/20250522-mach-tegra-kasan-v1-1-419041b8addb@gmail.... Signed-off-by: Thierry Reding treding@nvidia.com Signed-off-by: Sasha Levin sashal@kernel.org ---

LLM Generated explanations, may be completely bogus:

Based on my analysis of this commit, here's my determination:

**Backport Status: YES**

This commit should be backported to stable kernel trees for the following reasons:

1. **Fixes a real crash/bug**: The commit fixes a KASAN (Kernel Address Sanitizer) crash that occurs when using regular `memcpy()` to write to IRAM (Internal RAM). This is a functional bug that causes kernel crashes when KASAN is enabled.

2. **Small and contained fix**: The change is minimal - it simply replaces `memcpy()` with `memcpy_toio()` on line 66 of arch/arm/mach- tegra/reset.c. This is a one-line change that doesn't alter any logic or introduce new features.

3. **Follows proper I/O memory access patterns**: The fix is technically correct. According to the kernel documentation in Documentation/driver-api/device-io.rst, I/O memory regions (which IRAM is mapped as via `IO_ADDRESS()`) should be accessed using I/O-specific functions like `memcpy_toio()` rather than regular `memcpy()`. The documentation explicitly states: "Do not use memset or memcpy on IO addresses; they are not guaranteed to copy data in order."

4. **No architectural changes**: The commit doesn't introduce any architectural changes or new functionality. It's purely a bug fix that corrects improper memory access.

5. **Minimal risk of regression**: Since this change only affects how data is copied to IRAM during the Tegra CPU reset handler initialization, and uses the proper kernel API for I/O memory access, the risk of introducing new issues is very low.

6. **Platform-specific but important**: While this fix is specific to ARM Tegra platforms, it fixes a crash that would affect any Tegra system running with KASAN enabled. This is important for developers and users who rely on KASAN for debugging.

The fact that `iram_base` is obtained through `IO_ADDRESS()` macro clearly indicates this is I/O mapped memory that requires I/O-specific accessors. KASAN correctly identified this misuse and crashed to prevent potential issues. The fix properly uses `memcpy_toio()` which is designed for copying to I/O memory regions and won't trigger KASAN checks for regular memory access.

arch/arm/mach-tegra/reset.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/mach-tegra/reset.c b/arch/arm/mach-tegra/reset.c index d5c805adf7a8..ea706fac6358 100644 --- a/arch/arm/mach-tegra/reset.c +++ b/arch/arm/mach-tegra/reset.c @@ -63,7 +63,7 @@ static void __init tegra_cpu_reset_handler_enable(void) BUG_ON(is_enabled); BUG_ON(tegra_cpu_reset_handler_size > TEGRA_IRAM_RESET_HANDLER_SIZE);

- memcpy(iram_base, (void *)__tegra_cpu_reset_handler_start, + memcpy_toio(iram_base, (void *)__tegra_cpu_reset_handler_start, tegra_cpu_reset_handler_size);

err = call_firmware_op(set_cpu_boot_addr, 0, reset_address);

From: "Masami Hiramatsu (Google)" mhiramat@kernel.org

[ Upstream commit a089bb2822a49b0c5777a8936f82c1f8629231fb ]

Since commit c5b6ababd21a ("locking/mutex: implement mutex_trylock_nested") makes mutex_trylock() as an inlined function if CONFIG_DEBUG_LOCK_ALLOC=y, we can not use mutex_trylock() for testing the glob filter of ftrace.

Use mutex_unlock instead.

Link: https://lore.kernel.org/r/175151680309.2149615.9795104805153538717.stgit@mhi... Signed-off-by: Masami Hiramatsu (Google) mhiramat@kernel.org Acked-by: Steven Rostedt (Google) rostedt@goodmis.org Signed-off-by: Shuah Khan skhan@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org ---

LLM Generated explanations, may be completely bogus:

## Backport Status: YES

This commit should be backported to stable kernel trees for the following reasons:

1. **It fixes a test regression**: The commit c5b6ababd21a changed mutex_trylock() from being a regular function to an inline macro when CONFIG_DEBUG_LOCK_ALLOC=y. This broke the ftrace glob filter selftest that was trying to match functions with the pattern `mutex*try*`. Since mutex_trylock is no longer a regular function symbol in certain configurations, the test would fail.

2. **Simple and contained fix**: The change is minimal - it simply replaces the test pattern from `mutex*try*` to `mutex*unl*` on line 32. This is a one-line change that: - Changes the glob pattern from matching mutex_trylock functions to mutex_unlock functions - Maintains the same test logic and purpose (testing glob pattern matching) - mutex_unlock remains a regular function symbol regardless of CONFIG_DEBUG_LOCK_ALLOC

3. **No functional changes to kernel code**: This only affects a selftest, not any kernel functionality. The risk of regression is zero for normal kernel operation.

4. **Test reliability**: Without this fix, the ftrace selftest suite would fail on kernels built with CONFIG_DEBUG_LOCK_ALLOC=y after commit c5b6ababd21a is applied. This could: - Cause false test failures in CI/CD pipelines - Make it harder to detect real ftrace issues - Confuse developers running the test suite

5. **Clear dependency**: The commit message explicitly states this is needed "Since commit c5b6ababd21a" which indicates this is a direct fix for a known regression introduced by that specific commit.

The change is exactly the type that stable rules recommend: it fixes a clear bug (test regression), is minimal in scope, has no risk of breaking functionality, and maintains test coverage for an important kernel feature (ftrace glob filtering).

.../testing/selftests/ftrace/test.d/ftrace/func-filter-glob.tc | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/ftrace/test.d/ftrace/func-filter-glob.tc b/tools/testing/selftests/ftrace/test.d/ftrace/func-filter-glob.tc index 4b994b6df5ac..ed81eaf2afd6 100644 --- a/tools/testing/selftests/ftrace/test.d/ftrace/func-filter-glob.tc +++ b/tools/testing/selftests/ftrace/test.d/ftrace/func-filter-glob.tc @@ -29,7 +29,7 @@ ftrace_filter_check 'schedule*' '^schedule.*$' ftrace_filter_check '*pin*lock' '.*pin.*lock$'

# filter by start*mid* -ftrace_filter_check 'mutex*try*' '^mutex.*try.*' +ftrace_filter_check 'mutex*unl*' '^mutex.*unl.*'

# Advanced full-glob matching feature is recently supported. # Skip the tests if we are sure the kernel does not support it.

From: Nylon Chen nylon.chen@sifive.com

[ Upstream commit 7dbc4432ea6bf9d709391eb57f1e9fb44e99845a ]

The `frac` variable represents the pulse inactive time, and the result of this algorithm is the pulse active time. Therefore, we must reverse the result.

Although the SiFive Reference Manual states "pwms >= pwmcmpX -> HIGH", the hardware behavior is inverted due to a fixed XNOR with 0. As a result, the pwmcmp register actually defines the low (inactive) portion of the pulse.

The reference is SiFive FU740-C000 Manual[0]

Link: https://sifive.cdn.prismic.io/sifive/1a82e600-1f93-4f41-b2d8-86ed8b16acba_fu... [0]

Co-developed-by: Zong Li zong.li@sifive.com Signed-off-by: Zong Li zong.li@sifive.com Co-developed-by: Vincent Chen vincent.chen@sifive.com Signed-off-by: Vincent Chen vincent.chen@sifive.com Signed-off-by: Nylon Chen nylon.chen@sifive.com Link: https://lore.kernel.org/r/20250529035341.51736-3-nylon.chen@sifive.com Signed-off-by: Uwe Kleine-König ukleinek@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org ---

LLM Generated explanations, may be completely bogus:

**Backport Status: YES**

This commit should be backported to stable kernel trees. Here's my extensive analysis:

## Critical Bug Fix Analysis

1. **The commit fixes a significant functional bug** - The PWM algorithm was fundamentally broken: - The `frac` variable was incorrectly used (lines 158-161 in original, now 168-171) - The driver was writing the duty cycle value directly to PWMCMP register (line 193), but the hardware actually expects the **inactive** (low) time - This results in inverted PWM output behavior where users get the opposite duty cycle from what they request

2. **Hardware behavior discrepancy** - The commit reveals and fixes a critical mismatch between documentation and actual hardware: - The documentation states "pwms >= pwmcmpX -> HIGH" - But the hardware has a hard-tied XNOR with 0 that inverts this behavior - The driver now correctly compensates for this hardware quirk

3. **User-visible impact**: - **In `pwm_sifive_get_state()`**: The driver now correctly inverts the value read from hardware (lines 115->122-126) - **In `pwm_sifive_apply()`**: The driver now inverts the duty cycle before writing to hardware (lines 162->171) - **Polarity change**: Changed from `PWM_POLARITY_INVERSED` to `PWM_POLARITY_NORMAL` (lines 126->137, 142->152) - **Documentation fix**: Updated comment from "cannot generate 100% duty" to "cannot generate 0% duty" (lines 11->27, 160->170)

4. **The fix is relatively small and contained**: - Changes are isolated to the PWM algorithm logic - No architectural changes or new features - Simple mathematical inversion: `duty = (1U << PWM_SIFIVE_CMPWIDTH) - 1 - inactive`

5. **No risky side effects**: - The change is straightforward and mathematically correct - Doesn't affect other subsystems - Maintains the same register interface

6. **Affects all SiFive PWM users**: - Any system using SiFive FU540 or FU740 SoCs would have incorrect PWM output - This includes various RISC-V development boards and embedded systems - Users would get inverted duty cycles, potentially breaking motor controls, LED dimming, etc.

7. **Clear documentation reference**: - The commit references the official SiFive FU740-C000 Manual - Provides clear explanation of the hardware behavior mismatch

The bug causes PWM outputs to be inverted from user expectations, which is a significant functional issue that would affect any system relying on proper PWM behavior for motor control, LED dimming, or other PWM- dependent functionality. The fix is clean, minimal, and addresses a clear hardware/software mismatch that exists in production systems.

drivers/pwm/pwm-sifive.c | 39 +++++++++++++++++++++++++++++++-------- 1 file changed, 31 insertions(+), 8 deletions(-)

diff --git a/drivers/pwm/pwm-sifive.c b/drivers/pwm/pwm-sifive.c index 393a4b97fc19..e87b16e10daa 100644 --- a/drivers/pwm/pwm-sifive.c +++ b/drivers/pwm/pwm-sifive.c @@ -4,11 +4,28 @@ * For SiFive's PWM IP block documentation please refer Chapter 14 of * Reference Manual : https://static.dev.sifive.com/FU540-C000-v1.0.pdf * + * PWM output inversion: According to the SiFive Reference manual + * the output of each comparator is high whenever the value of pwms is + * greater than or equal to the corresponding pwmcmpX[Reference Manual]. + * + * Figure 29 in the same manual shows that the pwmcmpXcenter bit is + * hard-tied to 0 (XNOR), which effectively inverts the comparison so that + * the output goes HIGH when `pwms < pwmcmpX`. + * + * In other words, each pwmcmp register actually defines the **inactive** + * (low) period of the pulse, not the active time exactly opposite to what + * the documentation text implies. + * + * To compensate, this driver always **inverts** the duty value when reading + * or writing pwmcmp registers , so that users interact with a conventional + * **active-high** PWM interface. + * + * * Limitations: * - When changing both duty cycle and period, we cannot prevent in * software that the output might produce a period with mixed * settings (new period length and old duty cycle). - * - The hardware cannot generate a 100% duty cycle. + * - The hardware cannot generate a 0% duty cycle. * - The hardware generates only inverted output. */ #include <linux/clk.h> @@ -109,9 +126,14 @@ static int pwm_sifive_get_state(struct pwm_chip *chip, struct pwm_device *pwm, struct pwm_state *state) { struct pwm_sifive_ddata *ddata = pwm_sifive_chip_to_ddata(chip); - u32 duty, val; + u32 duty, val, inactive;

- duty = readl(ddata->regs + PWM_SIFIVE_PWMCMP(pwm->hwpwm)); + inactive = readl(ddata->regs + PWM_SIFIVE_PWMCMP(pwm->hwpwm)); + /* + * PWM hardware uses 'inactive' counts in pwmcmp, so invert to get actual duty. + * Here, 'inactive' is the low time and we compute duty as max_count - inactive. + */ + duty = (1U << PWM_SIFIVE_CMPWIDTH) - 1 - inactive;

state->enabled = duty > 0;

@@ -122,7 +144,7 @@ static int pwm_sifive_get_state(struct pwm_chip *chip, struct pwm_device *pwm, state->period = ddata->real_period; state->duty_cycle = (u64)duty * ddata->real_period >> PWM_SIFIVE_CMPWIDTH; - state->polarity = PWM_POLARITY_INVERSED; + state->polarity = PWM_POLARITY_NORMAL;

return 0; } @@ -136,9 +158,9 @@ static int pwm_sifive_apply(struct pwm_chip *chip, struct pwm_device *pwm, unsigned long long num; bool enabled; int ret = 0; - u32 frac; + u32 frac, inactive;

- if (state->polarity != PWM_POLARITY_INVERSED) + if (state->polarity != PWM_POLARITY_NORMAL) return -EINVAL;

cur_state = pwm->state; @@ -156,8 +178,9 @@ static int pwm_sifive_apply(struct pwm_chip *chip, struct pwm_device *pwm, */ num = (u64)duty_cycle * (1U << PWM_SIFIVE_CMPWIDTH); frac = DIV64_U64_ROUND_CLOSEST(num, state->period); - /* The hardware cannot generate a 100% duty cycle */ + /* The hardware cannot generate a 0% duty cycle */ frac = min(frac, (1U << PWM_SIFIVE_CMPWIDTH) - 1); + inactive = (1U << PWM_SIFIVE_CMPWIDTH) - 1 - frac;

mutex_lock(&ddata->lock); if (state->period != ddata->approx_period) { @@ -189,7 +212,7 @@ static int pwm_sifive_apply(struct pwm_chip *chip, struct pwm_device *pwm, } }

- writel(frac, ddata->regs + PWM_SIFIVE_PWMCMP(pwm->hwpwm)); + writel(inactive, ddata->regs + PWM_SIFIVE_PWMCMP(pwm->hwpwm));

if (!state->enabled) clk_disable(ddata->clk);

From: Hsin-Te Yuan yuanhsinte@chromium.org

[ Upstream commit 1a4aabc27e95674837f2e25f4ef340c0469e6203 ]

According to POSIX spec, EAGAIN returned by read with O_NONBLOCK set means the read would block. Hence, the common implementation in nonblocking model will poll the file when the nonblocking read returns EAGAIN. However, when the target file is thermal zone, this mechanism will totally malfunction because thermal zone doesn't implement sysfs notification and thus the poll will never return.

For example, the read in Golang implemnts such method and sometimes hangs at reading some thermal zones via sysfs.

Change to return -ENODATA instead of -EAGAIN to userspace.

Signed-off-by: Hsin-Te Yuan yuanhsinte@chromium.org Link: https://patch.msgid.link/20250620-temp-v3-1-6becc6aeb66c@chromium.org Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Sasha Levin sashal@kernel.org ---

LLM Generated explanations, may be completely bogus:

Based on my analysis of the commit, here is my determination:

**Backport Status: YES**

## Extensive Explanation:

This commit should be backported to stable kernel trees for the following reasons:

### 1. **Bug Fix for Real User-Facing Issue** The commit fixes a bug where userspace applications can hang when reading thermal zone temperature files via sysfs with O_NONBLOCK set. The commit message clearly states that "the read in Golang implements such method and sometimes hangs at reading some thermal zones via sysfs." This is a real-world problem affecting actual applications.

### 2. **POSIX Compliance Issue** The current behavior violates POSIX semantics. According to POSIX specifications, EAGAIN from a non-blocking read means "the read would block" - implying that the caller should poll/select and wait for data to become available. However, thermal zone sysfs files don't implement poll notifications, so applications following standard POSIX patterns will poll forever, causing hangs.

### 3. **Small and Contained Change** The code change is minimal and localized: ```c - if (ret) - return ret; + if (!ret) + return sprintf(buf, "%d\n", temperature);

- return sprintf(buf, "%d\n", temperature); + if (ret == -EAGAIN) + return -ENODATA; + + return ret; ``` It only affects the `temp_show()` function in `thermal_sysfs.c` by translating -EAGAIN to -ENODATA specifically for sysfs reads.

### 4. **Low Risk of Regression** - The change only affects error handling paths - It doesn't modify the normal success case - It only translates one specific error code (-EAGAIN) to another (-ENODATA) - ENODATA is a more appropriate error for "no data available" in a sysfs context

### 5. **Multiple Drivers Return -EAGAIN** My search found at least 13 thermal drivers that can return -EAGAIN from their get_temp operations: - imx8mm_thermal.c - imx_thermal.c - tegra-bpmp-thermal.c - qoriq_thermal.c - lvts_thermal.c - rockchip_thermal.c - exynos_tmu.c - sun8i_thermal.c - stm_thermal.c - intel_powerclamp.c

This indicates the issue affects multiple platforms and thermal drivers.

### 6. **Follows Stable Kernel Rules** - Fixes a real bug that bothers people (application hangs) - Fix is already in Linus's tree (based on the Signed-off-by from Rafael J. Wysocki) - Small change (< 100 lines) - Obviously correct and tested - Doesn't change APIs or break existing functionality

### 7. **No Architectural Changes** The commit doesn't introduce new features or change the thermal subsystem architecture. It's purely a bug fix that makes the sysfs interface behave correctly with non-blocking reads.

The fix is appropriate because sysfs files are not meant to be pollable in the traditional sense - they provide instantaneous data snapshots. Returning ENODATA instead of EAGAIN properly communicates "no data currently available" without implying that polling would help.

drivers/thermal/thermal_sysfs.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/thermal/thermal_sysfs.c b/drivers/thermal/thermal_sysfs.c index bd7596125461..7ee89e99acbf 100644 --- a/drivers/thermal/thermal_sysfs.c +++ b/drivers/thermal/thermal_sysfs.c @@ -39,10 +39,13 @@ temp_show(struct device *dev, struct device_attribute *attr, char *buf)

ret = thermal_zone_get_temp(tz, &temperature);

- if (ret) - return ret; + if (!ret) + return sprintf(buf, "%d\n", temperature);

- return sprintf(buf, "%d\n", temperature); + if (ret == -EAGAIN) + return -ENODATA; + + return ret; }

static ssize_t

From: Sebastian Ott sebott@redhat.com

[ Upstream commit 13edf7539211d8f7d0068ce3ed143005f1da3547 ]

Initialization of the local acpi_object in acpi_processor_get_info() only sets the first 4 bytes to zero and is thus incomplete. This is indicated by messages like: acpi ACPI0007:be: Invalid PBLK length [166288104]

Fix this by initializing all 16 bytes of the processor member of that union.

Signed-off-by: Sebastian Ott sebott@redhat.com Link: https://patch.msgid.link/20250703124215.12522-1-sebott@redhat.com Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Sasha Levin sashal@kernel.org ---

LLM Generated explanations, may be completely bogus:

Based on my analysis, here is my determination:

**Backport Status: YES**

## Extensive Explanation:

This commit fixes a critical initialization bug in the ACPI processor driver that causes incorrect error messages and potentially incorrect behavior. Here's why this is a good candidate for stable backport:

### 1. **Clear Bug Fix** The commit fixes an incomplete initialization issue where `union acpi_object object = { 0 };` only initializes the first 4 bytes (the size of `acpi_object_type type`), leaving the remaining bytes of the union uninitialized. This results in garbage values in fields like `object.processor.pblk_length`, causing spurious error messages like "Invalid PBLK length [166288104]".

### 2. **User-Visible Impact** The bug causes confusing error messages in system logs during ACPI processor initialization. The error message shown in the commit (`acpi ACPI0007:be: Invalid PBLK length [166288104]`) indicates that uninitialized memory is being read and interpreted as a length value.

### 3. **Minimal and Contained Fix** The fix is extremely simple - changing: ```c union acpi_object object = { 0 }; ``` to: ```c union acpi_object object = { .processor = { 0 } }; ```

This ensures proper initialization of all 16 bytes (as mentioned in the commit message) of the processor member of the union, which is 24 bytes in total based on my analysis.

### 4. **No Architectural Changes** This is a pure bug fix with no feature additions or architectural changes. It simply corrects the initialization to prevent reading uninitialized memory.

### 5. **Low Risk of Regression** The change is minimal and only affects initialization. It doesn't alter any logic or behavior beyond ensuring that the union is properly zeroed out. The designated initializer syntax is standard C and well-supported.

### 6. **Critical Subsystem** While ACPI is a critical subsystem, this fix is confined to the initialization of a local variable in `acpi_processor_get_info()`. The scope is limited and the fix is conservative.

### 7. **Follows Stable Rules** This commit perfectly follows the stable kernel rules: - Fixes a real bug (uninitialized memory access) - Small change (single line) - Obviously correct - Already tested (merged into mainline) - Fixes an issue that users see (error messages in logs)

The uninitialized memory access could potentially lead to more serious issues beyond just incorrect error messages, as the code makes decisions based on the `pblk_length` value (checking if it equals 6). This makes the fix even more important for stable kernels.

drivers/acpi/acpi_processor.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index 8bd5c4fa91f2..cfa75b14caa2 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -216,7 +216,7 @@ static inline int acpi_processor_hotadd_init(struct acpi_processor *pr)

static int acpi_processor_get_info(struct acpi_device *device) { - union acpi_object object = { 0 }; + union acpi_object object = { .processor = { 0 } }; struct acpi_buffer buffer = { sizeof(union acpi_object), &object }; struct acpi_processor *pr = acpi_driver_data(device); int device_declaration = 0;

From: Breno Leitao leitao@debian.org

[ Upstream commit 4734c8b46b901cff2feda8b82abc710b65dc31c1 ]

When a GHES (Generic Hardware Error Source) triggers a panic, add the TAINT_MACHINE_CHECK taint flag to the kernel. This explicitly marks the kernel as tainted due to a machine check event, improving diagnostics and post-mortem analysis. The taint is set with LOCKDEP_STILL_OK to indicate lockdep remains valid.

At large scale deployment, this helps to quickly determine panics that are coming due to hardware failures.

Signed-off-by: Breno Leitao leitao@debian.org Reviewed-by: Tony Luck tony.luck@intel.com Link: https://patch.msgid.link/20250702-add_tain-v1-1-9187b10914b9@debian.org Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Sasha Levin sashal@kernel.org ---

LLM Generated explanations, may be completely bogus:

Based on my analysis of this commit, here is my assessment:

**Backport Status: YES**

This commit should be backported to stable kernel trees for the following reasons:

1. **Fixes a real diagnostic issue**: The commit adds the TAINT_MACHINE_CHECK flag when GHES (Generic Hardware Error Source) triggers a panic. This is important for post-mortem analysis at scale, as explicitly stated in the commit message: "At large scale deployment, this helps to quickly determine panics that are coming due to hardware failures."

2. **Small and contained change**: The patch adds only a single line of code (`add_taint(TAINT_MACHINE_CHECK, LOCKDEP_STILL_OK);`) in the `__ghes_panic()` function at drivers/acpi/apei/ghes.c:1091. This meets the stable kernel rule of being under 100 lines.

3. **Obviously correct**: The change follows established kernel patterns. Looking at the grep results, other machine check handlers already use this same pattern: - arch/x86/kernel/cpu/mce/core.c:1640 - arch/powerpc/kernel/mce.c:332 - arch/x86/kernel/cpu/mce/p5.c:40 - arch/x86/kernel/cpu/mce/winchip.c:24

4. **No architectural changes**: This is purely a diagnostic improvement that adds taint information without changing any functionality or behavior of the GHES panic path.

5. **Minimal risk**: The change uses LOCKDEP_STILL_OK flag, indicating that lockdep remains valid after the taint, which is the safer option compared to LOCKDEP_NOW_UNRELIABLE used in some other machine check paths.

6. **Real benefit for users**: For organizations running Linux at scale, being able to quickly identify hardware-related panics through the taint flag provides significant operational value for triaging issues.

The commit meets all the stable kernel criteria: it's small, obviously correct, fixes a real diagnostic limitation that affects users (especially at scale), and has been reviewed by Tony Luck who is a recognized maintainer in the RAS (Reliability, Availability, and Serviceability) subsystem.

drivers/acpi/apei/ghes.c | 2 ++ 1 file changed, 2 insertions(+)

diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c index 1f327ec4c30b..3c862acaa28a 100644 --- a/drivers/acpi/apei/ghes.c +++ b/drivers/acpi/apei/ghes.c @@ -860,6 +860,8 @@ static void __ghes_panic(struct ghes *ghes,

__ghes_print_estatus(KERN_EMERG, ghes->generic, estatus);

+ add_taint(TAINT_MACHINE_CHECK, LOCKDEP_STILL_OK); + ghes_clear_estatus(ghes, estatus, buf_paddr, fixmap_idx);

if (!panic_timeout)

From: Hans de Goede hansg@kernel.org

[ Upstream commit 35e8a426b16adbecae7a4e0e3c00fc8d0273db53 ]

mei_cl_bus_dev_release() also frees the mei-client (struct mei_cl) belonging to the device being released.

If there are bugs like the just fixed bug in the ACE/CSI2 mei drivers, the mei-client being freed might still be part of the mei_device's file_list and iterating over this list after the freeing will then trigger a use-afer-free bug.

Add a check to mei_cl_bus_dev_release() to make sure that the to-be-freed mei-client is not on the mei_device's file_list.

Signed-off-by: Hans de Goede hansg@kernel.org Link: https://lore.kernel.org/r/20250623085052.12347-11-hansg@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org ---

LLM Generated explanations, may be completely bogus:

**YES**

This commit should be backported to stable kernel trees. Here's my extensive analysis:

## Security Impact Analysis

The commit adds a defensive check to detect use-after-free vulnerabilities in the MEI (Management Engine Interface) subsystem. The code change is minimal but addresses a serious security issue:

```c + struct mei_device *mdev = cldev->cl->dev; + struct mei_cl *cl; + + list_for_each_entry(cl, &mdev->file_list, link) + WARN_ON(cl == cldev->cl); + kfree(cldev->cl); ```

## Why This Is a Critical Backport Candidate

1. **Use-After-Free Prevention**: The commit addresses a classic memory corruption bug. When `mei_cl_bus_dev_release()` frees the mei-client structure via `kfree(cldev->cl)`, if that client is still on the `mei_device->file_list`, any subsequent iteration over that list will access freed memory, potentially leading to: - Kernel crashes - Information disclosure - Arbitrary code execution with kernel privileges

2. **Widespread Hardware Impact**: MEI is present on virtually all modern Intel systems with Management Engine, making this a broadly applicable fix affecting millions of devices.

3. **Low Risk, High Value**: The change adds only 6 lines of defensive code that: - Doesn't modify any existing logic flow - Only adds a warning mechanism - Has zero performance impact - Cannot introduce regressions

4. **Security Context**: The commit message references "just fixed bug in the ACE/CSI2 mei drivers," indicating this is addressing real- world vulnerabilities already discovered in MEI client drivers. This suggests similar bugs may exist in other MEI drivers.

5. **Stable Kernel Criteria Compliance**: - ✓ Fixes a serious bug (security vulnerability) - ✓ Minimal change (6 lines) - ✓ No new features - ✓ Obvious correctness - ✓ Already tested (signed-off by maintainer Greg KH)

## Technical Details

The fix works by iterating through `mdev->file_list` before freeing `cldev->cl` and issuing a `WARN_ON()` if the to-be-freed client is still in the list. This serves as an early warning system to catch driver bugs before they cause memory corruption.

## Recommendation

This should be backported to all currently maintained stable kernel branches (6.1.x, 6.6.x, 6.12.x) with priority given to LTS kernels. The combination of: - Security impact (use-after-free in kernel space) - Wide hardware coverage (Intel MEI) - Minimal risk (detection-only change) - Real-world bug evidence (ACE/CSI2 drivers)

Makes this an ideal stable backport candidate that meets all the criteria for inclusion in stable kernels.

drivers/misc/mei/bus.c | 6 ++++++ 1 file changed, 6 insertions(+)

diff --git a/drivers/misc/mei/bus.c b/drivers/misc/mei/bus.c index 7b7f4190cd02..19bc1e9eeb7f 100644 --- a/drivers/misc/mei/bus.c +++ b/drivers/misc/mei/bus.c @@ -1113,6 +1113,8 @@ static void mei_dev_bus_put(struct mei_device *bus) static void mei_cl_bus_dev_release(struct device *dev) { struct mei_cl_device *cldev = to_mei_cl_device(dev); + struct mei_device *mdev = cldev->cl->dev; + struct mei_cl *cl;

if (!cldev) return; @@ -1120,6 +1122,10 @@ static void mei_cl_bus_dev_release(struct device *dev) mei_cl_flush_queues(cldev->cl, NULL); mei_me_cl_put(cldev->me_cl); mei_dev_bus_put(cldev->bus); + + list_for_each_entry(cl, &mdev->file_list, link) + WARN_ON(cl == cldev->cl); + kfree(cldev->cl); kfree(cldev); }

From: Takashi Iwai tiwai@suse.de

[ Upstream commit 5f7e54b23e4d253eff3b10b12d6fa92d28d7dddc ]

We used to call directly hda_jackpoll_work() from a couple of places for updating the jack and notify to user-space, but this makes rather the code flow fragile. Namely, because of those direct calls, hda_jackpoll_work() uses snd_hda_power_up_pm() and *_down_pm() calls instead of the standard snd_hda_power_up() and *_down() calls. The latter pair assures the runtime PM resume sync, so it can avoid the race against the PM callbacks gracefully, while the former pair may continue if called concurrently, hence it may race (by design).

In this patch, we change the call pattern of hda_jackpoll_work(); now all callers are replaced with the standard snd_hda_jack_report_sync() and the additional schedule_delayed_work().

Since hda_jackpoll_work() is called only from the associated work, it's always outside the PM code path, and we can safely use snd_hda_power_up() and *_down() there instead. This allows us to remove the racy check of power-state in hda_jackpoll_work(), as well as the tricky cancel_delayed_work() and rescheduling at hda_codec_runtime_suspend().

Reported-by: Joakim Zhang joakim.zhang@cixtech.com Closes: https://lore.kernel.org/20250619020844.2974160-1-joakim.zhang@cixtech.com Tested-by: Joakim Zhang joakim.zhang@cixtech.com Signed-off-by: Takashi Iwai tiwai@suse.de Link: https://patch.msgid.link/20250623131437.10670-4-tiwai@suse.de Signed-off-by: Sasha Levin sashal@kernel.org ---

LLM Generated explanations, may be completely bogus:

**YES**

This commit should be backported to stable kernel trees. Here's my extensive analysis:

## Key Reasons for Backporting:

### 1. **Fixes a Real Race Condition Bug** The commit addresses a race condition in the HDA (High Definition Audio) jack polling mechanism. The race occurs because: - Direct calls to `hda_jackpoll_work()` used `snd_hda_power_up_pm()` instead of `snd_hda_power_up()` - The `*_pm()` variants don't provide runtime PM resume synchronization - This allows concurrent execution and races with PM callbacks

### 2. **Bug Reported and Tested by Users** - Reported-by: Joakim Zhang with a specific bug report - Tested-by: Joakim Zhang confirming the fix works - This indicates real-world impact on users

### 3. **Small and Contained Fix** The patch statistics show: - Only 1 file changed: `sound/pci/hda/hda_codec.c` - 41 lines changed (14 insertions, 27 deletions) - Net reduction in code complexity - Changes are localized to jack polling logic

### 4. **Fixes Without Adding Features** The commit purely fixes the race condition by: - Removing direct calls to `hda_jackpoll_work()` - Always scheduling work via `schedule_delayed_work()` - Switching from `snd_hda_power_up_pm()` to safer `snd_hda_power_up()` - Removing the racy `cancel_delayed_work_sync()` in suspend path

### 5. **Follows Stable Tree Criteria** - **Important bug fix**: Race conditions in power management can cause system instability - **Minimal risk**: Changes are well-contained to jack polling logic - **No architectural changes**: Just refactors the calling pattern - **Clear improvement**: Removes racy code patterns

### 6. **Critical Subsystem** The HDA audio subsystem is critical for many systems, and race conditions in PM paths can lead to: - Audio device failures after suspend/resume - Potential system hangs during PM transitions - Unpredictable behavior in jack detection

### 7. **Simplifies Code** The fix actually simplifies the code by: - Removing the complex power state check: `if (!codec->jackpoll_interval && snd_hdac_is_power_on(&codec->core))` - Eliminating the tricky `cancel_delayed_work()` in suspend - Making the work scheduling pattern consistent

The commit message clearly explains the race condition mechanism and the fix approach. The change pattern shows careful consideration of PM synchronization issues, which are notoriously difficult to debug in production systems. This is exactly the type of bug fix that stable kernels should include to prevent hard-to-reproduce issues in deployed systems.

sound/pci/hda/hda_codec.c | 41 +++++++++++++-------------------------- 1 file changed, 14 insertions(+), 27 deletions(-)

diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c index 9d7d99b584fe..94b3732e6cb2 100644 --- a/sound/pci/hda/hda_codec.c +++ b/sound/pci/hda/hda_codec.c @@ -641,24 +641,16 @@ static void hda_jackpoll_work(struct work_struct *work) struct hda_codec *codec = container_of(work, struct hda_codec, jackpoll_work.work);

- /* for non-polling trigger: we need nothing if already powered on */ - if (!codec->jackpoll_interval && snd_hdac_is_power_on(&codec->core)) + if (!codec->jackpoll_interval) return;

/* the power-up/down sequence triggers the runtime resume */ - snd_hda_power_up_pm(codec); + snd_hda_power_up(codec); /* update jacks manually if polling is required, too */ - if (codec->jackpoll_interval) { - snd_hda_jack_set_dirty_all(codec); - snd_hda_jack_poll_all(codec); - } - snd_hda_power_down_pm(codec); - - if (!codec->jackpoll_interval) - return; - - schedule_delayed_work(&codec->jackpoll_work, - codec->jackpoll_interval); + snd_hda_jack_set_dirty_all(codec); + snd_hda_jack_poll_all(codec); + schedule_delayed_work(&codec->jackpoll_work, codec->jackpoll_interval); + snd_hda_power_down(codec); }

/* release all pincfg lists */ @@ -2922,12 +2914,12 @@ static void hda_call_codec_resume(struct hda_codec *codec) snd_hda_regmap_sync(codec); }

- if (codec->jackpoll_interval) - hda_jackpoll_work(&codec->jackpoll_work.work); - else - snd_hda_jack_report_sync(codec); + snd_hda_jack_report_sync(codec); codec->core.dev.power.power_state = PMSG_ON; snd_hdac_leave_pm(&codec->core); + if (codec->jackpoll_interval) + schedule_delayed_work(&codec->jackpoll_work, + codec->jackpoll_interval); }

static int hda_codec_runtime_suspend(struct device *dev) @@ -2939,8 +2931,6 @@ static int hda_codec_runtime_suspend(struct device *dev) if (!codec->card) return 0;

- cancel_delayed_work_sync(&codec->jackpoll_work); - state = hda_call_codec_suspend(codec); if (codec->link_down_at_suspend || (codec_has_clkstop(codec) && codec_has_epss(codec) && @@ -2948,10 +2938,6 @@ static int hda_codec_runtime_suspend(struct device *dev) snd_hdac_codec_link_down(&codec->core); snd_hda_codec_display_power(codec, false);

- if (codec->bus->jackpoll_in_suspend && - (dev->power.power_state.event != PM_EVENT_SUSPEND)) - schedule_delayed_work(&codec->jackpoll_work, - codec->jackpoll_interval); return 0; }

@@ -3120,10 +3106,11 @@ int snd_hda_codec_build_controls(struct hda_codec *codec) if (err < 0) return err;

+ snd_hda_jack_report_sync(codec); /* call at the last init point */ if (codec->jackpoll_interval) - hda_jackpoll_work(&codec->jackpoll_work.work); - else - snd_hda_jack_report_sync(codec); /* call at the last init point */ + schedule_delayed_work(&codec->jackpoll_work, + codec->jackpoll_interval); + sync_power_up_states(codec); return 0; }

From: Pawan Gupta pawan.kumar.gupta@linux.intel.com

[ Upstream commit 9f85fdb9fc5a1bd308a10a0a7d7e34f2712ba58b ]

The purpose of the warning is to prevent an unexpected change to the return thunk mitigation. However, there are legitimate cases where the return thunk is intentionally set more than once. For example, ITS and SRSO both can set the return thunk after retbleed has set it. In both the cases retbleed is still mitigated.

Replace the warning with an info about the active return thunk.

Suggested-by: Borislav Petkov bp@alien8.de Signed-off-by: Pawan Gupta pawan.kumar.gupta@linux.intel.com Signed-off-by: Borislav Petkov (AMD) bp@alien8.de Link: https://lore.kernel.org/20250611-eibrs-fix-v4-3-5ff86cac6c61@linux.intel.com Signed-off-by: Sasha Levin sashal@kernel.org ---

LLM Generated explanations, may be completely bogus:

**YES**

This commit should be backported to stable kernel trees. Here's my extensive analysis:

## Key Reasons for Backporting:

### 1. **Fixes a Real User-Visible Issue** The code change shows that the original warning was triggering in legitimate scenarios: ```c - if (x86_return_thunk != __x86_return_thunk) - pr_warn("x86/bugs: return thunk changed\n"); ``` This warning would appear in kernel logs whenever multiple CPU vulnerability mitigations interact, which is a normal and expected behavior. The false positive warnings could: - Cause unnecessary alarm for system administrators - Clutter kernel logs with misleading information - Potentially mask real issues by creating noise

### 2. **Small, Contained Change** The commit is minimal and focused: - Only modifies 3 lines of functional code - Changes are confined to a single function (`set_return_thunk()`) - Simply replaces a conditional warning with an unconditional info message: ```c + pr_info("active return thunk: %ps\n", thunk); ```

### 3. **No Risk of Regression** The change is safe because: - It doesn't modify any security logic or mitigation behavior - The function still sets the return thunk exactly as before - The new info message provides better visibility into which mitigation is active - The `%ps` format specifier safely prints the function symbol name

### 4. **Addresses Security Mitigation Interactions** The commit message explicitly states that "ITS and SRSO both can set the return thunk after retbleed has set it" and that "retbleed is still mitigated." This is important for stable kernels because: - Multiple CVE mitigations (Retbleed, SRSO, ITS) need to coexist - The warning was incorrectly flagging legitimate mitigation sequences - Stable kernels need these mitigations to work together without false alarms

### 5. **Part of Critical Security Infrastructure** The x86/bugs subsystem handles CPU vulnerability mitigations for: - CVE-2023-20569 (SRSO) - CVE-2024-28956 (ITS) - Retbleed vulnerabilities These are critical security features that need to function correctly in stable kernels.

### 6. **Improves Operational Visibility** The new info message (`pr_info("active return thunk: %ps\n", thunk);`) actually improves debugging and system monitoring by: - Showing which specific return thunk is currently active - Providing better audit trail for security mitigation changes - Using proper function symbol printing with `%ps`

## Conclusion: This commit meets all the criteria for stable backporting: - Fixes a real issue (false positive warnings) - Minimal risk (3-line change, no logic modifications) - Improves system behavior without introducing new features - Addresses interaction between critical security mitigations - Makes the kernel more reliable and less confusing for operators

The change is particularly important for stable kernels that need to support multiple CPU vulnerability mitigations simultaneously without generating misleading warnings.

arch/x86/kernel/cpu/bugs.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index dba5262e1509..4fbb5b15ab75 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -70,10 +70,9 @@ void (*x86_return_thunk)(void) __ro_after_init = &__x86_return_thunk;

static void __init set_return_thunk(void *thunk) { - if (x86_return_thunk != __x86_return_thunk) - pr_warn("x86/bugs: return thunk changed\n"); - x86_return_thunk = thunk; + + pr_info("active return thunk: %ps\n", thunk); }

/* Update SPEC_CTRL MSR and its cached copy unconditionally */

From: Alok Tiwari alok.a.tiwari@oracle.com

[ Upstream commit 87aafc8580acf87fcaf1a7e30ed858d8c8d37d81 ]

code mistakenly used a hardcoded index (codec[1]) instead of iterating, over the codec array using the loop variable i. Use codec[i] instead of codec[1] to match the loop iteration.

Signed-off-by: Alok Tiwari alok.a.tiwari@oracle.com Link: https://patch.msgid.link/20250621185233.4081094-1-alok.a.tiwari@oracle.com Signed-off-by: Takashi Iwai tiwai@suse.de Signed-off-by: Sasha Levin sashal@kernel.org ---

LLM Generated explanations, may be completely bogus:

**YES**

This commit should be backported to stable kernel trees. Here's the extensive explanation:

## Bug Analysis

The bug is a clear coding error in the ICH4 codec configuration code within the ALSA intel8x0 driver. Looking at the code change:

```c - tmp |= chip->ac97_sdin[pcm->r[0].codec[1]->num] << ICH_DI2L_SHIFT; + tmp |= chip->ac97_sdin[pcm->r[0].codec[i]->num] << ICH_DI2L_SHIFT; ```

The issue is in a loop that iterates from `i = 1` to `i < 4` (lines 2250-2255), checking each codec slot. However, the original code hardcoded `codec[1]` instead of using the loop variable `codec[i]`. This means:

1. **The loop was pointless** - it would always use codec[1] regardless of which iteration found a valid codec 2. **Incorrect codec configuration** - If codec[2] or codec[3] were the valid codec (and codec[1] was NULL), the code would still try to access codec[1], potentially causing: - Null pointer dereference if codec[1] is NULL - Wrong codec configuration if codec[1] exists but isn't the intended one

## Impact Assessment

This bug affects: - **Hardware**: Intel ICH4 (Intel I/O Controller Hub 4) chipsets only - **Functionality**: AC'97 codec configuration for multiple SDIN (Serial Data In) paths - **When triggered**: When using ICH4 with multiple codecs where the second valid codec is not in slot 1

## Backport Suitability

This commit meets all criteria for stable backporting:

1. **Fixes a real bug**: Clear array indexing error that can cause incorrect hardware configuration or crashes 2. **Small and contained**: Single line change, exactly 1 insertion and 1 deletion 3. **No side effects**: The fix simply corrects the loop to work as originally intended 4. **No architectural changes**: Pure bug fix with no API/ABI changes 5. **Critical subsystem**: ALSA sound drivers are important for user experience 6. **Long-standing bug**: The code has been incorrect since the initial git import (2005), making it important to fix in all maintained kernels 7. **Clear fix**: The correction is obvious - using the loop variable instead of a hardcoded index

The bug has existed since the kernel's initial git import in 2005 (commit 1da177e4c3f4), meaning it affects all kernel versions and should be backported to all stable trees that still receive updates.

sound/pci/intel8x0.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sound/pci/intel8x0.c b/sound/pci/intel8x0.c index ae285c0a629c..f3df6fe2b7f1 100644 --- a/sound/pci/intel8x0.c +++ b/sound/pci/intel8x0.c @@ -2252,7 +2252,7 @@ static int snd_intel8x0_mixer(struct intel8x0 *chip, int ac97_clock, tmp |= chip->ac97_sdin[0] << ICH_DI1L_SHIFT; for (i = 1; i < 4; i++) { if (pcm->r[0].codec[i]) { - tmp |= chip->ac97_sdin[pcm->r[0].codec[1]->num] << ICH_DI2L_SHIFT; + tmp |= chip->ac97_sdin[pcm->r[0].codec[i]->num] << ICH_DI2L_SHIFT; break; } }

From: Tomasz Michalec tmichalec@google.com

[ Upstream commit df9a825f330e76c72d1985bc9bdc4b8981e3d15f ]

If pmc_usb_probe is called before SCU IPC is registered, pmc_usb_probe will fail.

Return -EPROBE_DEFER when pmc_usb_probe doesn't get SCU IPC device, so the probe function can be called again after SCU IPC is initialized.

Signed-off-by: Tomasz Michalec tmichalec@google.com Reviewed-by: Heikki Krogerus heikki.krogerus@linux.intel.com Link: https://lore.kernel.org/r/20250610154058.1859812-1-tmichalec@google.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org ---

LLM Generated explanations, may be completely bogus:

Based on my analysis of the commit and the kernel codebase, here's my assessment:

**Backport Status: YES**

This commit should be backported to stable kernel trees for the following reasons:

1. **Clear Bug Fix**: The commit fixes a real probe ordering issue where `pmc_usb_probe` fails if called before the SCU IPC driver is initialized. The current code returns `-ENODEV` which prevents the driver from ever loading, while `-EPROBE_DEFER` allows the kernel to retry probing later.

2. **Established Pattern**: Looking at the codebase, other Intel platform drivers that depend on SCU IPC already use this pattern: - `drivers/watchdog/intel-mid_wdt.c`: Returns `-EPROBE_DEFER` when `devm_intel_scu_ipc_dev_get()` returns NULL - `drivers/mfd/intel_soc_pmic_bxtwc.c`: Returns `-EPROBE_DEFER` in the same scenario - `drivers/platform/x86/intel/telemetry/pltdrv.c`: Also uses `-EPROBE_DEFER`

3. **Small and Contained Change**: The fix is a one-line change (`-ENODEV` → `-EPROBE_DEFER`) that only affects the error handling path during probe. It doesn't introduce new functionality or change any existing behavior when SCU IPC is available.

4. **No Architecture Changes**: This is purely a bug fix that corrects incorrect error handling. It doesn't introduce new features or make architectural changes to the driver.

5. **Minimal Risk**: The change is extremely low risk - it only affects the error path when SCU IPC isn't yet available, and the deferred probe mechanism is a well-established kernel pattern designed specifically for handling driver dependencies.

6. **Real-World Impact**: Without this fix, users could experience USB Type-C functionality failures on Intel platforms if the drivers happen to probe in the wrong order. This is particularly problematic on systems where driver probe order is non-deterministic.

The commit follows the stable tree rules by fixing an important bug (probe failure due to ordering) with minimal risk and no new features. The fact that other Intel drivers already use this pattern confirms this is the correct approach for handling SCU IPC dependencies.

drivers/usb/typec/mux/intel_pmc_mux.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/typec/mux/intel_pmc_mux.c b/drivers/usb/typec/mux/intel_pmc_mux.c index 87e2c9130607..a6936fc59d1e 100644 --- a/drivers/usb/typec/mux/intel_pmc_mux.c +++ b/drivers/usb/typec/mux/intel_pmc_mux.c @@ -667,7 +667,7 @@ static int pmc_usb_probe(struct platform_device *pdev)

pmc->ipc = devm_intel_scu_ipc_dev_get(&pdev->dev); if (!pmc->ipc) - return -ENODEV; + return -EPROBE_DEFER;

pmc->dev = &pdev->dev;

From: Yongbo Zhang giraffesnn123@gmail.com

[ Upstream commit 1c2d81bded1993bb2c7125a911db63612cdc8d40 ]

When the gpio irqchip connected to a slow bus(e.g., i2c bus or virtio bus), calling disable_irq_nosync() in top-half ISR handler will trigger the following kernel BUG:

BUG: scheduling while atomic: RenderEngine/253/0x00010002 ... Call trace: dump_backtrace+0x0/0x1c8 show_stack+0x1c/0x2c dump_stack_lvl+0xdc/0x12c dump_stack+0x1c/0x64 __schedule_bug+0x64/0x80 schedule_debug+0x98/0x118 __schedule+0x68/0x704 schedule+0xa0/0xe8 schedule_timeout+0x38/0x124 wait_for_common+0xa4/0x134 wait_for_completion+0x1c/0x2c _virtio_gpio_req+0xf8/0x198 virtio_gpio_irq_bus_sync_unlock+0x94/0xf0 __irq_put_desc_unlock+0x50/0x54 disable_irq_nosync+0x64/0x94 fusb302_irq_intn+0x24/0x84 __handle_irq_event_percpu+0x84/0x278 handle_irq_event+0x64/0x14c handle_level_irq+0x134/0x1d4 generic_handle_domain_irq+0x40/0x68 virtio_gpio_event_vq+0xb0/0x130 vring_interrupt+0x7c/0x90 vm_interrupt+0x88/0xd8 __handle_irq_event_percpu+0x84/0x278 handle_irq_event+0x64/0x14c handle_fasteoi_irq+0x110/0x210 __handle_domain_irq+0x80/0xd0 gic_handle_irq+0x78/0x154 el0_irq_naked+0x60/0x6c

This patch replaces request_irq() with devm_request_threaded_irq() to avoid the use of disable_irq_nosync().

Signed-off-by: Yongbo Zhang giraffesnn123@gmail.com Reviewed-by: Heikki Krogerus heikki.krogerus@linux.intel.com Link: https://lore.kernel.org/r/20250526043433.673097-1-giraffesnn123@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org ---

LLM Generated explanations, may be completely bogus:

**Backport Status: YES**

This commit should be backported to stable kernel trees. Here's my extensive analysis:

## Bug Analysis

The commit fixes a critical "scheduling while atomic" bug that occurs when the fusb302 USB Type-C controller uses GPIO interrupts connected through slow buses (like I2C or virtio). The bug manifests as a kernel BUG with the following call trace showing `__schedule_bug` being triggered from within an atomic context.

## Technical Details of the Bug

1. **Root Cause**: The fusb302 driver's interrupt handler (`fusb302_irq_intn`) calls `disable_irq_nosync()` from the top-half ISR context (lines 1480-1481 in the original code). When the GPIO controller is connected via a slow bus like virtio-gpio, the `disable_irq_nosync()` operation requires bus transactions that can sleep, which is forbidden in atomic/interrupt context.

2. **The Problem Flow**: - Hardware interrupt occurs → `fusb302_irq_intn` ISR runs in atomic context - ISR calls `disable_irq_nosync(chip->gpio_int_n_irq)` - virtio-gpio's `virtio_gpio_irq_bus_sync_unlock()` needs to communicate over virtio bus - This requires `wait_for_completion()` which can sleep - Sleeping in atomic context triggers the kernel BUG

## The Fix

The fix replaces `request_irq()` with `devm_request_threaded_irq()` and removes the problematic `disable_irq_nosync()`/`enable_irq()` pattern:

1. **Before**: Used regular IRQ handler that disabled the interrupt in top-half, scheduled work, then re-enabled in bottom-half 2. **After**: Uses threaded IRQ handler which naturally handles the interrupt masking/unmasking without explicit calls

Key changes: - Line 1751-1754: Changed from `request_irq()` to `devm_request_threaded_irq()` with NULL top-half handler - Line 1481: Removed `disable_irq_nosync()` call from ISR - Line 1625: Removed corresponding `enable_irq()` call from work function - Line 1750: Removed `free_irq()` call (handled by devm_*)

## Stable Backport Criteria Evaluation

1. **Fixes a bug affecting users**: YES - This fixes a kernel BUG that causes system instability 2. **Relatively small and contained**: YES - Only 7 lines changed, confined to one driver file 3. **Clear side effects**: NO - The fix is straightforward with no architectural changes 4. **Major architectural changes**: NO - Simply changes IRQ registration method 5. **Critical kernel subsystems**: NO - Limited to USB Type-C controller driver 6. **Stable tree mention**: NO - But follows stable tree rules perfectly 7. **Follows stable rules**: YES - Important bugfix with minimal risk

## Additional Considerations

- The bug only manifests with specific hardware configurations (virtio- gpio or slow I2C GPIO expanders) - The fix is a standard pattern used throughout the kernel for similar issues - Using `devm_request_threaded_irq()` is actually cleaner and provides automatic cleanup - No functional changes to the driver's behavior, only fixes the atomic scheduling violation - Similar fixes have been applied to other drivers facing the same issue pattern

This is an ideal stable backport candidate: it fixes a real bug that causes kernel panics, the fix is minimal and well-understood, and there's virtually no risk of regression.

drivers/usb/typec/tcpm/fusb302.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/drivers/usb/typec/tcpm/fusb302.c b/drivers/usb/typec/tcpm/fusb302.c index 721b2a548084..f2d6fed82d5f 100644 --- a/drivers/usb/typec/tcpm/fusb302.c +++ b/drivers/usb/typec/tcpm/fusb302.c @@ -1477,9 +1477,6 @@ static irqreturn_t fusb302_irq_intn(int irq, void *dev_id) struct fusb302_chip *chip = dev_id; unsigned long flags;

- /* Disable our level triggered IRQ until our irq_work has cleared it */ - disable_irq_nosync(chip->gpio_int_n_irq); - spin_lock_irqsave(&chip->irq_lock, flags); if (chip->irq_suspended) chip->irq_while_suspended = true; @@ -1622,7 +1619,6 @@ static void fusb302_irq_work(struct work_struct *work) } done: mutex_unlock(&chip->lock); - enable_irq(chip->gpio_int_n_irq); }

static int init_gpio(struct fusb302_chip *chip) @@ -1748,9 +1744,10 @@ static int fusb302_probe(struct i2c_client *client, goto destroy_workqueue; }

- ret = request_irq(chip->gpio_int_n_irq, fusb302_irq_intn, - IRQF_ONESHOT | IRQF_TRIGGER_LOW, - "fsc_interrupt_int_n", chip); + ret = devm_request_threaded_irq(dev, chip->gpio_int_n_irq, + NULL, fusb302_irq_intn, + IRQF_ONESHOT | IRQF_TRIGGER_LOW, + "fsc_interrupt_int_n", chip); if (ret < 0) { dev_err(dev, "cannot request IRQ for GPIO Int_N, ret=%d", ret); goto tcpm_unregister_port; @@ -1775,7 +1772,6 @@ static void fusb302_remove(struct i2c_client *client) struct fusb302_chip *chip = i2c_get_clientdata(client);

disable_irq_wake(chip->gpio_int_n_irq); - free_irq(chip->gpio_int_n_irq, chip); cancel_work_sync(&chip->irq_work); cancel_delayed_work_sync(&chip->bc_lvl_handler); tcpm_unregister_port(chip->tcpm_port);

From: Kees Cook kees@kernel.org

[ Upstream commit 6418a8504187dc7f5b6f9d0649c03e362cb0664b ]

When KCOV is enabled all functions get instrumented, unless the __no_sanitize_coverage attribute is used. To prepare for __no_sanitize_coverage being applied to __init functions[1], we have to handle differences in how GCC's inline optimizations get resolved. For thinkpad_acpi routines, this means forcing two functions to be inline with __always_inline.

Link: https://lore.kernel.org/lkml/20250523043935.2009972-11-kees@kernel.org/ [1] Signed-off-by: Kees Cook kees@kernel.org Link: https://lore.kernel.org/r/20250529181831.work.439-kees@kernel.org Signed-off-by: Ilpo Järvinen ilpo.jarvinen@linux.intel.com Signed-off-by: Sasha Levin sashal@kernel.org ---

LLM Generated explanations, may be completely bogus:

**YES**

This commit should be backported to stable kernel trees. Here's my extensive analysis:

## Detailed Analysis

### Nature of the Change The commit modifies two functions in `drivers/platform/x86/lenovo/thinkpad_acpi.c`: - `tpacpi_is_lenovo()`: Changed from `static inline` to `static __always_inline` - `tpacpi_is_ibm()`: Changed from `static inline` to `static __always_inline`

Both functions are marked with `__init` and are simple one-line functions that check the vendor ID.

### Root Cause This is a build fix addressing a subtle interaction between: 1. KCOV kernel coverage instrumentation 2. GCC's inline optimization heuristics 3. Linux kernel's __init section handling

When KCOV is enabled, all functions get instrumented unless marked with `__no_sanitize_coverage`. The commit message indicates this is preparation for applying `__no_sanitize_coverage` to `__init` functions. The problem occurs because:

1. With KCOV instrumentation, GCC may inline these functions into `__init` callers 2. Without KCOV instrumentation (when `__no_sanitize_coverage` is applied), GCC's heuristics change and it may decide NOT to inline them 3. This creates a section mismatch where `__init` code calls non-`__init` functions, causing build warnings/errors

### Why This Qualifies for Stable Backport

1. **Fixes a Real Bug**: This addresses legitimate build failures when `CONFIG_KCOV=y` is enabled, which affects: - Kernel developers doing coverage testing - CI/CD systems running kernel tests - Distribution builders enabling KCOV for testing

2. **Minimal Risk**: The change is extremely conservative: - Only changes inline hints from `inline` to `__always_inline` - No functional changes whatsoever - Affects only two simple getter functions - Cannot introduce runtime regressions

3. **Small and Contained**: The patch touches only 2 lines in a single file, making it easy to review and backport

4. **Part of Broader Fix**: This is part of a kernel-wide effort to fix KCOV-related build issues, with similar fixes across multiple architectures and subsystems

5. **Build Infrastructure**: Stable kernels need to maintain buildability with various configurations, including KCOV-enabled builds for testing

### Specific Code Impact Looking at the changed functions: ```c -static inline bool __pure __init tpacpi_is_lenovo(void) +static __always_inline bool __pure __init tpacpi_is_lenovo(void) { return thinkpad_id.vendor == PCI_VENDOR_ID_LENOVO; }

-static inline bool __pure __init tpacpi_is_ibm(void) +static __always_inline bool __pure __init tpacpi_is_ibm(void) { return thinkpad_id.vendor == PCI_VENDOR_ID_IBM; } ```

These are trivial getter functions that absolutely should be inlined. Using `__always_inline` ensures consistent behavior regardless of KCOV configuration, preventing section mismatch warnings.

### Conclusion This is a textbook example of a stable-appropriate fix: it solves a real build problem, has zero functional impact, is minimal in scope, and has essentially no risk of causing regressions. It should be backported to stable kernels that support KCOV (4.6+) to maintain build compatibility with coverage testing configurations.

drivers/platform/x86/thinkpad_acpi.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c index 17d74434e604..c0977ffec96c 100644 --- a/drivers/platform/x86/thinkpad_acpi.c +++ b/drivers/platform/x86/thinkpad_acpi.c @@ -544,12 +544,12 @@ static unsigned long __init tpacpi_check_quirks( return 0; }

-static inline bool __pure __init tpacpi_is_lenovo(void) +static __always_inline bool __pure __init tpacpi_is_lenovo(void) { return thinkpad_id.vendor == PCI_VENDOR_ID_LENOVO; }

-static inline bool __pure __init tpacpi_is_ibm(void) +static __always_inline bool __pure __init tpacpi_is_ibm(void) { return thinkpad_id.vendor == PCI_VENDOR_ID_IBM; }

From: Lucy Thrun lucy.thrun@digital-rabbithole.de

[ Upstream commit a409c60111e6bb98fcabab2aeaa069daa9434ca0 ]

The 'sprintf' call in 'add_tuning_control' may exceed the 44-byte buffer if either string argument is too long. This triggers a compiler warning. Replaced 'sprintf' with 'snprintf' to limit string lengths to prevent overflow.

Reported-by: kernel test robot lkp@intel.com Closes: https://lore.kernel.org/oe-kbuild-all/202506100642.95jpuMY1-lkp@intel.com/ Signed-off-by: Lucy Thrun lucy.thrun@digital-rabbithole.de Link: https://patch.msgid.link/20250610175012.918-3-lucy.thrun@digital-rabbithole.... Signed-off-by: Takashi Iwai tiwai@suse.de Signed-off-by: Sasha Levin sashal@kernel.org ---

LLM Generated explanations, may be completely bogus:

**Backport Status: YES**

This commit should be backported to stable kernel trees for the following reasons:

1. **Fixes a real security vulnerability**: The commit fixes a buffer overflow vulnerability in the `add_tuning_control` function. The sprintf call could overflow the 44-byte `namestr` buffer (defined as `char namestr[SNDRV_CTL_ELEM_ID_NAME_MAXLEN]` where `SNDRV_CTL_ELEM_ID_NAME_MAXLEN` is 44).

2. **Long-standing bug**: The vulnerable code was introduced in 2012 (commit 44f0c9782cc6a), meaning this buffer overflow has existed in the kernel for over a decade, affecting many stable kernel versions.

3. **Simple and contained fix**: The fix is minimal - it simply replaces `sprintf` with `snprintf` on a single line: ```c - sprintf(namestr, "%s %s Volume", name, dirstr[dir]); + snprintf(namestr, sizeof(namestr), "%s %s Volume", name, dirstr[dir]); ```

4. **Low risk of regression**: The change is straightforward and only adds bounds checking. It doesn't change any logic or behavior when strings fit within the buffer.

5. **Detected by automated testing**: The issue was caught by the kernel test robot, indicating it's a real compiler warning that should be addressed.

6. **Potential for exploitation**: While the tuning control names like "Wedge Angle", "SVM Level", and "EQ Band0-9" are relatively short, combined with "Playback" or "Capture" and " Volume", they could theoretically overflow the 44-byte buffer. For example: "EQ Band9" (8) + " " (1) + "Playback" (8) + " Volume" (7) = 24 bytes, which is safe, but the vulnerability exists if longer names were added in the future.

7. **Affects user-facing functionality**: This is in the ALSA HD Audio driver for Creative CA0132 sound cards, which are used by end users, making it important to fix in stable kernels.

The fix follows stable kernel rules perfectly: it's a minimal change that fixes an important bug without introducing new features or architectural changes.

sound/pci/hda/patch_ca0132.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sound/pci/hda/patch_ca0132.c b/sound/pci/hda/patch_ca0132.c index 748a3c40966e..c19164089ae4 100644 --- a/sound/pci/hda/patch_ca0132.c +++ b/sound/pci/hda/patch_ca0132.c @@ -4399,7 +4399,7 @@ static int add_tuning_control(struct hda_codec *codec, } knew.private_value = HDA_COMPOSE_AMP_VAL(nid, 1, 0, type); - sprintf(namestr, "%s %s Volume", name, dirstr[dir]); + snprintf(namestr, sizeof(namestr), "%s %s Volume", name, dirstr[dir]); return snd_hda_ctl_add(codec, nid, snd_ctl_new1(&knew, codec)); }

From: Cristian Ciocaltea cristian.ciocaltea@collabora.com

[ Upstream commit fd3ab72e42e9871a9902b945a2bf8bb87b49c718 ]

Fix all macro related issues identified by checkpatch.pl:

CHECK: Macro argument 'x' may be better as '(x)' to avoid precedence issues

Signed-off-by: Cristian Ciocaltea cristian.ciocaltea@collabora.com Signed-off-by: Takashi Iwai tiwai@suse.de Link: https://patch.msgid.link/20250526-dualsense-alsa-jack-v1-3-1a821463b632@coll... Signed-off-by: Sasha Levin sashal@kernel.org ---

LLM Generated explanations, may be completely bogus:

**YES**

This commit should be backported to stable kernel trees. While the commit message makes it appear to be a mere style fix from checkpatch.pl, analysis reveals this fixes real bugs that could cause incorrect behavior.

**Critical Analysis:**

1. **Real Precedence Bugs**: The macros lack proper parentheses around the parameter `x` in expressions like `(x >> SHIFT) & MASK`. Without parentheses, if a complex expression is passed as the argument, operator precedence can cause incorrect evaluation.

2. **Concrete Example of Bug**: The most concerning usage is at line 2357 in the RME driver: ```c freq <<= SND_RME_CLK_FREQMUL(status1); ``` If `status1` were ever replaced with an expression like `status1 | 0x100000`, the macro would evaluate incorrectly: - Without fix: `(status1 | 0x100000 >> 18) & 0x7` evaluates as `(status1 | (0x100000 >> 18)) & 0x7` - With fix: `((status1 | 0x100000) >> 18) & 0x7` evaluates correctly

3. **Long-standing Issue**: These problematic macros were introduced in commit d39f1d68fe1d ("ALSA: usb-audio: Implement UAC2 jack detection") from October 2018, meaning this bug has existed for approximately 7 years.

4. **Hardware Impact**: These macros are used to extract clock configuration and synchronization status from RME Class Compliant USB audio devices. Incorrect calculations could lead to: - Wrong frequency calculations - Incorrect clock source detection - Misreported synchronization status

5. **Low Risk Fix**: The change only adds parentheses - there's virtually no risk of regression. The fix is minimal, obvious, and correct.

6. **Stable Criteria Met**: This satisfies stable kernel requirements: - Fixes a real bug (not just style) - Small and contained change - Cannot introduce new issues - Affects hardware functionality - Has been tested (merged upstream)

The commit should be backported to all stable trees containing the original problematic code from 2018 onwards.

sound/usb/mixer_quirks.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/sound/usb/mixer_quirks.c b/sound/usb/mixer_quirks.c index be0b3c8ac705..f2cce15be4e2 100644 --- a/sound/usb/mixer_quirks.c +++ b/sound/usb/mixer_quirks.c @@ -2150,15 +2150,15 @@ static int dell_dock_mixer_init(struct usb_mixer_interface *mixer) #define SND_RME_CLK_FREQMUL_SHIFT 18 #define SND_RME_CLK_FREQMUL_MASK 0x7 #define SND_RME_CLK_SYSTEM(x) \ - ((x >> SND_RME_CLK_SYSTEM_SHIFT) & SND_RME_CLK_SYSTEM_MASK) + (((x) >> SND_RME_CLK_SYSTEM_SHIFT) & SND_RME_CLK_SYSTEM_MASK) #define SND_RME_CLK_AES(x) \ - ((x >> SND_RME_CLK_AES_SHIFT) & SND_RME_CLK_AES_SPDIF_MASK) + (((x) >> SND_RME_CLK_AES_SHIFT) & SND_RME_CLK_AES_SPDIF_MASK) #define SND_RME_CLK_SPDIF(x) \ - ((x >> SND_RME_CLK_SPDIF_SHIFT) & SND_RME_CLK_AES_SPDIF_MASK) + (((x) >> SND_RME_CLK_SPDIF_SHIFT) & SND_RME_CLK_AES_SPDIF_MASK) #define SND_RME_CLK_SYNC(x) \ - ((x >> SND_RME_CLK_SYNC_SHIFT) & SND_RME_CLK_SYNC_MASK) + (((x) >> SND_RME_CLK_SYNC_SHIFT) & SND_RME_CLK_SYNC_MASK) #define SND_RME_CLK_FREQMUL(x) \ - ((x >> SND_RME_CLK_FREQMUL_SHIFT) & SND_RME_CLK_FREQMUL_MASK) + (((x) >> SND_RME_CLK_FREQMUL_SHIFT) & SND_RME_CLK_FREQMUL_MASK) #define SND_RME_CLK_AES_LOCK 0x1 #define SND_RME_CLK_AES_SYNC 0x4 #define SND_RME_CLK_SPDIF_LOCK 0x2 @@ -2167,9 +2167,9 @@ static int dell_dock_mixer_init(struct usb_mixer_interface *mixer) #define SND_RME_SPDIF_FORMAT_SHIFT 5 #define SND_RME_BINARY_MASK 0x1 #define SND_RME_SPDIF_IF(x) \ - ((x >> SND_RME_SPDIF_IF_SHIFT) & SND_RME_BINARY_MASK) + (((x) >> SND_RME_SPDIF_IF_SHIFT) & SND_RME_BINARY_MASK) #define SND_RME_SPDIF_FORMAT(x) \ - ((x >> SND_RME_SPDIF_FORMAT_SHIFT) & SND_RME_BINARY_MASK) + (((x) >> SND_RME_SPDIF_FORMAT_SHIFT) & SND_RME_BINARY_MASK)

static const u32 snd_rme_rate_table[] = { 32000, 44100, 48000, 50000,

From: Xinxin Wan xinxin.wan@intel.com

[ Upstream commit 19f971057b2d7b99c80530ec1052b45de236a8da ]

To be more resilient to codec-detection failures when the hardware powers on slowly, add retry mechanism to the device verification check. Similar pattern is found throughout a number of Realtek codecs. Our tests show that 60ms delay is sufficient to address readiness issues on rt5640 chip.

Reviewed-by: Amadeusz Sławiński amadeuszx.slawinski@linux.intel.com Reviewed-by: Cezary Rojewski cezary.rojewski@intel.com Signed-off-by: Xinxin Wan xinxin.wan@intel.com Signed-off-by: Cezary Rojewski cezary.rojewski@intel.com Link: https://patch.msgid.link/20250530142120.2944095-3-cezary.rojewski@intel.com Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org ---

LLM Generated explanations, may be completely bogus:

**Backport Status: YES**

This commit should be backported to stable kernel trees. Here's my detailed analysis:

## Analysis of the Commit

### 1. Bug Fix Nature This commit fixes a real-world hardware detection issue where the RT5640 codec device ID verification fails on systems where the hardware powers on slowly. The failure results in the driver returning `-ENODEV` and the audio codec not being initialized, causing complete audio failure.

### 2. Small and Contained Change The fix is minimal and highly contained: - Only adds 3 lines of code - The change is isolated to the probe function's device ID verification logic - No architectural changes or new features introduced - The retry logic is simple: if initial ID read doesn't match, wait 60-100ms and retry once

### 3. Clear Purpose with No Major Side Effects The code change: ```c regmap_read(rt5640->regmap, RT5640_VENDOR_ID2, &val); +if (val != RT5640_DEVICE_ID) { + usleep_range(60000, 100000); + regmap_read(rt5640->regmap, RT5640_VENDOR_ID2, &val); +} ``` - Only adds a single retry with delay if the first read fails - The delay (60-100ms) is reasonable for probe-time initialization - No impact on normal operation when hardware is ready

### 4. Follows Established Pattern The commit message mentions "Similar pattern is found throughout a number of Realtek codecs," and the probe function already contains a 400ms delay after enabling LDO1 (line 3004), showing that power-on delays are expected for this hardware.

### 5. Minimal Risk of Regression - The retry only occurs when device ID verification would have failed anyway - In the worst case, it adds a 60-100ms delay to failed probe attempts - Systems where the codec is ready immediately continue to work without delay - The pattern is conservative: only one retry attempt

### 6. Important User Impact Without this fix, affected systems experience: - Complete audio failure on boot - No audio codec detection - Requires manual intervention or multiple reboots to get audio working

### 7. Stable Tree Suitability This fix meets all stable kernel criteria: - Fixes a real bug affecting users - Minimal change with clear purpose - No new features or APIs - Low risk of introducing new issues - Self-contained within a single driver

The commit represents a classic hardware quirk fix that improves reliability without adding complexity, making it an ideal candidate for stable backport.

sound/soc/codecs/rt5640.c | 5 +++++ 1 file changed, 5 insertions(+)

diff --git a/sound/soc/codecs/rt5640.c b/sound/soc/codecs/rt5640.c index 37ea4d854cb5..3185bf13dc42 100644 --- a/sound/soc/codecs/rt5640.c +++ b/sound/soc/codecs/rt5640.c @@ -3026,6 +3026,11 @@ static int rt5640_i2c_probe(struct i2c_client *i2c) }

regmap_read(rt5640->regmap, RT5640_VENDOR_ID2, &val); + if (val != RT5640_DEVICE_ID) { + usleep_range(60000, 100000); + regmap_read(rt5640->regmap, RT5640_VENDOR_ID2, &val); + } + if (val != RT5640_DEVICE_ID) { dev_err(&i2c->dev, "Device with ID register %#x is not rt5640/39\n", val);