From: Claudiu Beznea <claudiu.beznea.uj(a)bp.renesas.com>
The phy-rcar-gen3-usb2 driver exposes four individual PHYs that are
requested and configured by PHY users. The struct phy_ops APIs access the
same set of registers to configure all PHYs. Additionally, PHY settings can
be modified through sysfs or an IRQ handler. While some struct phy_ops APIs
are protected by a driver-wide mutex, others rely on individual
PHY-specific mutexes.
This approach can lead to various issues, including:
1/ the IRQ handler may interrupt PHY settings in progress, racing with
hardware configuration protected by a mutex lock
2/ due to msleep(20) in rcar_gen3_init_otg(), while a configuration thread
suspends to wait for the delay, another thread may try to configure
another PHY (with phy_init() + phy_power_on()); re-running the
phy_init() goes to the exact same configuration code, re-running the
same hardware configuration on the same set of registers (and bits)
which might impact the result of the msleep for the 1st configuring
thread
3/ sysfs can configure the hardware (though role_store()) and it can
still race with the phy_init()/phy_power_on() APIs calling into the
drivers struct phy_ops
To address these issues, add a spinlock to protect hardware register access
and driver private data structures (e.g., calls to
rcar_gen3_is_any_rphy_initialized()). Checking driver-specific data remains
necessary as all PHY instances share common settings. With this change,
the existing mutex protection is removed and the cleanup.h helpers are
used.
While at it, to keep the code simpler, do not skip
regulator_enable()/regulator_disable() APIs in
rcar_gen3_phy_usb2_power_on()/rcar_gen3_phy_usb2_power_off() as the
regulators enable/disable operations are reference counted anyway.
Fixes: f3b5a8d9b50d ("phy: rcar-gen3-usb2: Add R-Car Gen3 USB2 PHY driver")
Cc: stable(a)vger.kernel.org
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh(a)renesas.com>
Tested-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh(a)renesas.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj(a)bp.renesas.com>
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj(a)bp.renesas.com>
---
Changes in v3:
- collected tags
Changes in v2:
- collected tags
drivers/phy/renesas/phy-rcar-gen3-usb2.c | 49 +++++++++++++-----------
1 file changed, 26 insertions(+), 23 deletions(-)
diff --git a/drivers/phy/renesas/phy-rcar-gen3-usb2.c b/drivers/phy/renesas/phy-rcar-gen3-usb2.c
index aa9f301b5acb..39c73399b039 100644
--- a/drivers/phy/renesas/phy-rcar-gen3-usb2.c
+++ b/drivers/phy/renesas/phy-rcar-gen3-usb2.c
@@ -9,6 +9,7 @@
* Copyright (C) 2014 Cogent Embedded, Inc.
*/
+#include <linux/cleanup.h>
#include <linux/extcon-provider.h>
#include <linux/interrupt.h>
#include <linux/io.h>
@@ -118,7 +119,7 @@ struct rcar_gen3_chan {
struct regulator *vbus;
struct reset_control *rstc;
struct work_struct work;
- struct mutex lock; /* protects rphys[...].powered */
+ spinlock_t lock; /* protects access to hardware and driver data structure. */
enum usb_dr_mode dr_mode;
u32 obint_enable_bits;
bool extcon_host;
@@ -348,6 +349,8 @@ static ssize_t role_store(struct device *dev, struct device_attribute *attr,
bool is_b_device;
enum phy_mode cur_mode, new_mode;
+ guard(spinlock_irqsave)(&ch->lock);
+
if (!ch->is_otg_channel || !rcar_gen3_is_any_otg_rphy_initialized(ch))
return -EIO;
@@ -415,7 +418,7 @@ static void rcar_gen3_init_otg(struct rcar_gen3_chan *ch)
val = readl(usb2_base + USB2_ADPCTRL);
writel(val | USB2_ADPCTRL_IDPULLUP, usb2_base + USB2_ADPCTRL);
}
- msleep(20);
+ mdelay(20);
writel(0xffffffff, usb2_base + USB2_OBINTSTA);
writel(ch->obint_enable_bits, usb2_base + USB2_OBINTEN);
@@ -436,12 +439,14 @@ static irqreturn_t rcar_gen3_phy_usb2_irq(int irq, void *_ch)
if (pm_runtime_suspended(dev))
goto rpm_put;
- status = readl(usb2_base + USB2_OBINTSTA);
- if (status & ch->obint_enable_bits) {
- dev_vdbg(dev, "%s: %08x\n", __func__, status);
- writel(ch->obint_enable_bits, usb2_base + USB2_OBINTSTA);
- rcar_gen3_device_recognition(ch);
- ret = IRQ_HANDLED;
+ scoped_guard(spinlock, &ch->lock) {
+ status = readl(usb2_base + USB2_OBINTSTA);
+ if (status & ch->obint_enable_bits) {
+ dev_vdbg(dev, "%s: %08x\n", __func__, status);
+ writel(ch->obint_enable_bits, usb2_base + USB2_OBINTSTA);
+ rcar_gen3_device_recognition(ch);
+ ret = IRQ_HANDLED;
+ }
}
rpm_put:
@@ -456,6 +461,8 @@ static int rcar_gen3_phy_usb2_init(struct phy *p)
void __iomem *usb2_base = channel->base;
u32 val;
+ guard(spinlock_irqsave)(&channel->lock);
+
/* Initialize USB2 part */
val = readl(usb2_base + USB2_INT_ENABLE);
val |= USB2_INT_ENABLE_UCOM_INTEN | rphy->int_enable_bits;
@@ -479,6 +486,8 @@ static int rcar_gen3_phy_usb2_exit(struct phy *p)
void __iomem *usb2_base = channel->base;
u32 val;
+ guard(spinlock_irqsave)(&channel->lock);
+
rphy->initialized = false;
val = readl(usb2_base + USB2_INT_ENABLE);
@@ -498,16 +507,17 @@ static int rcar_gen3_phy_usb2_power_on(struct phy *p)
u32 val;
int ret = 0;
- mutex_lock(&channel->lock);
- if (!rcar_gen3_are_all_rphys_power_off(channel))
- goto out;
-
if (channel->vbus) {
ret = regulator_enable(channel->vbus);
if (ret)
- goto out;
+ return ret;
}
+ guard(spinlock_irqsave)(&channel->lock);
+
+ if (!rcar_gen3_are_all_rphys_power_off(channel))
+ goto out;
+
val = readl(usb2_base + USB2_USBCTR);
val |= USB2_USBCTR_PLL_RST;
writel(val, usb2_base + USB2_USBCTR);
@@ -517,7 +527,6 @@ static int rcar_gen3_phy_usb2_power_on(struct phy *p)
out:
/* The powered flag should be set for any other phys anyway */
rphy->powered = true;
- mutex_unlock(&channel->lock);
return 0;
}
@@ -528,18 +537,12 @@ static int rcar_gen3_phy_usb2_power_off(struct phy *p)
struct rcar_gen3_chan *channel = rphy->ch;
int ret = 0;
- mutex_lock(&channel->lock);
- rphy->powered = false;
-
- if (!rcar_gen3_are_all_rphys_power_off(channel))
- goto out;
+ scoped_guard(spinlock_irqsave, &channel->lock)
+ rphy->powered = false;
if (channel->vbus)
ret = regulator_disable(channel->vbus);
-out:
- mutex_unlock(&channel->lock);
-
return ret;
}
@@ -750,7 +753,7 @@ static int rcar_gen3_phy_usb2_probe(struct platform_device *pdev)
if (phy_data->no_adp_ctrl)
channel->obint_enable_bits = USB2_OBINT_IDCHG_EN;
- mutex_init(&channel->lock);
+ spin_lock_init(&channel->lock);
for (i = 0; i < NUM_OF_PHYS; i++) {
channel->rphys[i].phy = devm_phy_create(dev, NULL,
phy_data->phy_usb2_ops);
--
2.43.0
Getting / Setting the frame interval using the V4L2 subdev pad ops
get_frame_interval/set_frame_interval causes a deadlock, as the
subdev state is locked in the [1] but also in the driver itself.
In [2] it's described that the caller is responsible to acquire and
release the lock in this case. Therefore, acquiring the lock in the
driver is wrong.
Remove the lock acquisitions/releases from mt9m114_ifp_get_frame_interval()
and mt9m114_ifp_set_frame_interval().
[1] drivers/media/v4l2-core/v4l2-subdev.c - line 1129
[2] Documentation/driver-api/media/v4l2-subdev.rst
Fixes: 24d756e914fc ("media: i2c: Add driver for onsemi MT9M114 camera sensor")
Cc: stable(a)vger.kernel.org
Signed-off-by: Mathis Foerst <mathis.foerst(a)mt.com>
---
drivers/media/i2c/mt9m114.c | 8 --------
1 file changed, 8 deletions(-)
diff --git a/drivers/media/i2c/mt9m114.c b/drivers/media/i2c/mt9m114.c
index 18419de6491d..9ab1147a9aaf 100644
--- a/drivers/media/i2c/mt9m114.c
+++ b/drivers/media/i2c/mt9m114.c
@@ -1644,13 +1644,9 @@ static int mt9m114_ifp_get_frame_interval(struct v4l2_subdev *sd,
if (interval->which != V4L2_SUBDEV_FORMAT_ACTIVE)
return -EINVAL;
- mutex_lock(sensor->ifp.hdl.lock);
-
ival->numerator = 1;
ival->denominator = sensor->ifp.frame_rate;
- mutex_unlock(sensor->ifp.hdl.lock);
-
return 0;
}
@@ -1669,8 +1665,6 @@ static int mt9m114_ifp_set_frame_interval(struct v4l2_subdev *sd,
if (interval->which != V4L2_SUBDEV_FORMAT_ACTIVE)
return -EINVAL;
- mutex_lock(sensor->ifp.hdl.lock);
-
if (ival->numerator != 0 && ival->denominator != 0)
sensor->ifp.frame_rate = min_t(unsigned int,
ival->denominator / ival->numerator,
@@ -1684,8 +1678,6 @@ static int mt9m114_ifp_set_frame_interval(struct v4l2_subdev *sd,
if (sensor->streaming)
ret = mt9m114_set_frame_rate(sensor);
- mutex_unlock(sensor->ifp.hdl.lock);
-
return ret;
}
--
2.34.1
The following commit has been merged into the x86/urgent branch of tip:
Commit-ID: 8177c6bedb7013cf736137da586cf783922309dd
Gitweb: https://git.kernel.org/tip/8177c6bedb7013cf736137da586cf783922309dd
Author: Ahmed S. Darwish <darwi(a)linutronix.de>
AuthorDate: Tue, 04 Mar 2025 09:51:12 +01:00
Committer: Ingo Molnar <mingo(a)kernel.org>
CommitterDate: Tue, 04 Mar 2025 09:59:14 +01:00
x86/cacheinfo: Validate CPUID leaf 0x2 EDX output
CPUID leaf 0x2 emits one-byte descriptors in its four output registers
EAX, EBX, ECX, and EDX. For these descriptors to be valid, the most
significant bit (MSB) of each register must be clear.
The historical Git commit:
019361a20f016 ("- pre6: Intel: start to add Pentium IV specific stuff (128-byte cacheline etc)...")
introduced leaf 0x2 output parsing. It only validated the MSBs of EAX,
EBX, and ECX, but left EDX unchecked.
Validate EDX's most-significant bit.
Signed-off-by: Ahmed S. Darwish <darwi(a)linutronix.de>
Signed-off-by: Ingo Molnar <mingo(a)kernel.org>
Cc: stable(a)vger.kernel.org
Cc: "H. Peter Anvin" <hpa(a)zytor.com>
Cc: Linus Torvalds <torvalds(a)linux-foundation.org>
Link: https://lore.kernel.org/r/20250304085152.51092-2-darwi@linutronix.de
---
arch/x86/kernel/cpu/cacheinfo.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kernel/cpu/cacheinfo.c b/arch/x86/kernel/cpu/cacheinfo.c
index e6fa03e..a6c6bcc 100644
--- a/arch/x86/kernel/cpu/cacheinfo.c
+++ b/arch/x86/kernel/cpu/cacheinfo.c
@@ -808,7 +808,7 @@ void init_intel_cacheinfo(struct cpuinfo_x86 *c)
cpuid(2, ®s[0], ®s[1], ®s[2], ®s[3]);
/* If bit 31 is set, this is an unknown format */
- for (j = 0 ; j < 3 ; j++)
+ for (j = 0 ; j < 4 ; j++)
if (regs[j] & (1 << 31))
regs[j] = 0;
The PWM allow configuring the PWM resolution from 8 bits PWM
values up to 15 bits values, for the Hi-Res PWMs, and then either
6-bit or 9-bit for the normal PWMs. The current implementation loops
through all possible resolutions (PWM sizes), for the PWM subtype, on top
of the already existing process of determining the prediv, exponent and
refclk.
The first and second issues are related to capping the computed PWM
value.
The third issue is that it uses the wrong maximum possible PWM
value for determining the best matched period.
Fix all of them.
Signed-off-by: Abel Vesa <abel.vesa(a)linaro.org>
---
Changes in v3:
- Added a new patch that fixes the normal PWMs, since they now support
6-bit resolution as well. Added it as first patch.
- Re-worded the second patch. Included Bjorn's suggestion and R-b tag.
- Link to v2: https://lore.kernel.org/r/20250226-leds-qcom-lpg-fix-max-pwm-on-hi-res-v2-0…
Changes in v2:
- Re-worded the commit to drop the details that are not important
w.r.t. what the patch is fixing.
- Added another patch which fixes the resolution used for determining
best matched period and PWM config.
- Link to v1: https://lore.kernel.org/r/20250220-leds-qcom-lpg-fix-max-pwm-on-hi-res-v1-1…
---
Abel Vesa (3):
leds: rgb: leds-qcom-lpg: Fix pwm resolution max for normal PWMs
leds: rgb: leds-qcom-lpg: Fix pwm resolution max for Hi-Res PWMs
leds: rgb: leds-qcom-lpg: Fix calculation of best period Hi-Res PWMs
drivers/leds/rgb/leds-qcom-lpg.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
---
base-commit: cd3215bbcb9d4321def93fea6cfad4d5b42b9d1d
change-id: 20250220-leds-qcom-lpg-fix-max-pwm-on-hi-res-067e8782a79b
Best regards,
--
Abel Vesa <abel.vesa(a)linaro.org>