From: Johannes Berg johannes.berg@intel.com
[ Upstream commit 04516706bb99889986ddfa3a769ed50d2dc7ac13 ]
When we read device memory, we lock a spinlock, write the address we want to read from the device and then spin in a loop reading the data in 32-bit quantities from another register.
As the description makes clear, this is rather inefficient, incurring a PCIe bus transaction for every read. In a typical device today, we want to read 786k SMEM if it crashes, leading to 192k register reads. Occasionally, we've seen the whole loop take over 20 seconds and then triggering the soft lockup detector.
Clearly, it is unreasonable to spin here for such extended periods of time.
To fix this, break the loop down into an outer and an inner loop, and break out of the inner loop if more than half a second elapsed. To avoid too much overhead, check for that only every 128 reads, though there's no particular reason for that number. Then, unlock and relock to obtain NIC access again, reprogram the start address and continue.
This will keep (interrupt) latencies on the CPU down to a reasonable time.
Signed-off-by: Johannes Berg johannes.berg@intel.com Signed-off-by: Mordechay Goodstein mordechay.goodstein@intel.com Signed-off-by: Luca Coelho luciano.coelho@intel.com Signed-off-by: Kalle Valo kvalo@codeaurora.org Link: https://lore.kernel.org/r/iwlwifi.20201022165103.45878a7e49aa.I3b9b9c5a10002... Signed-off-by: Sasha Levin sashal@kernel.org --- .../net/wireless/intel/iwlwifi/pcie/trans.c | 36 ++++++++++++++----- 1 file changed, 27 insertions(+), 9 deletions(-)
diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c index e7b873018dca6..e1287c3421165 100644 --- a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c +++ b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c @@ -1904,18 +1904,36 @@ static int iwl_trans_pcie_read_mem(struct iwl_trans *trans, u32 addr, void *buf, int dwords) { unsigned long flags; - int offs, ret = 0; + int offs = 0; u32 *vals = buf;
- if (iwl_trans_grab_nic_access(trans, &flags)) { - iwl_write32(trans, HBUS_TARG_MEM_RADDR, addr); - for (offs = 0; offs < dwords; offs++) - vals[offs] = iwl_read32(trans, HBUS_TARG_MEM_RDAT); - iwl_trans_release_nic_access(trans, &flags); - } else { - ret = -EBUSY; + while (offs < dwords) { + /* limit the time we spin here under lock to 1/2s */ + ktime_t timeout = ktime_add_us(ktime_get(), 500 * USEC_PER_MSEC); + + if (iwl_trans_grab_nic_access(trans, &flags)) { + iwl_write32(trans, HBUS_TARG_MEM_RADDR, + addr + 4 * offs); + + while (offs < dwords) { + vals[offs] = iwl_read32(trans, + HBUS_TARG_MEM_RDAT); + offs++; + + /* calling ktime_get is expensive so + * do it once in 128 reads + */ + if (offs % 128 == 0 && ktime_after(ktime_get(), + timeout)) + break; + } + iwl_trans_release_nic_access(trans, &flags); + } else { + return -EBUSY; + } } - return ret; + + return 0; }
static int iwl_trans_pcie_write_mem(struct iwl_trans *trans, u32 addr,
From: Markus Reichl m.reichl@fivetechno.de
[ Upstream commit 0011c6d182774fc781fb9e115ebe8baa356029ae ]
Recently introduced async probe on mmc devices can shuffle block IDs. Pin them to fixed values to ease booting in environments where UUIDs are not practical. Use newly introduced aliases for mmcblk devices from [1].
[1] https://patchwork.kernel.org/patch/11747669/
Signed-off-by: Markus Reichl m.reichl@fivetechno.de Reviewed-by: Douglas Anderson dianders@chromium.org Link: https://lore.kernel.org/r/20201104162356.1251-1-m.reichl@fivetechno.de Signed-off-by: Heiko Stuebner heiko@sntech.de Signed-off-by: Sasha Levin sashal@kernel.org --- arch/arm64/boot/dts/rockchip/rk3399.dtsi | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/arch/arm64/boot/dts/rockchip/rk3399.dtsi b/arch/arm64/boot/dts/rockchip/rk3399.dtsi index 7afbfb0f96a3c..dd211dbdaaae0 100644 --- a/arch/arm64/boot/dts/rockchip/rk3399.dtsi +++ b/arch/arm64/boot/dts/rockchip/rk3399.dtsi @@ -65,6 +65,9 @@ aliases { i2c6 = &i2c6; i2c7 = &i2c7; i2c8 = &i2c8; + mmc0 = &sdio0; + mmc1 = &sdmmc; + mmc2 = &sdhci; serial0 = &uart0; serial1 = &uart1; serial2 = &uart2;
From: Vineet Gupta vgupta@synopsys.com
[ Upstream commit e42404fa10fd11fe72d0a0e149a321d10e577715 ]
To start stack unwinding (SP, PC and BLINK) are needed. When the explicit execution context (pt_regs etc) is not available, unwinder assumes the task is sleeping (in __switch_to()) and fetches SP and BLINK from kernel mode stack.
But this assumption is not true, specially in a SMP system, when top runs on 1 core, there may be active running processes on all cores.
So when unwinding non courrent tasks, ensure they are NOT running.
And while at it, handle the self unwinding case explicitly.
This came out of investigation of a customer reported hang with rcutorture+top
Link: https://github.com/foss-for-synopsys-dwc-arc-processors/linux/issues/31 Signed-off-by: Vineet Gupta vgupta@synopsys.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/arc/kernel/stacktrace.c | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-)
diff --git a/arch/arc/kernel/stacktrace.c b/arch/arc/kernel/stacktrace.c index 165158735aa6b..3ee19b1e79be5 100644 --- a/arch/arc/kernel/stacktrace.c +++ b/arch/arc/kernel/stacktrace.c @@ -39,15 +39,15 @@
#ifdef CONFIG_ARC_DW2_UNWIND
-static void seed_unwind_frame_info(struct task_struct *tsk, - struct pt_regs *regs, - struct unwind_frame_info *frame_info) +static int +seed_unwind_frame_info(struct task_struct *tsk, struct pt_regs *regs, + struct unwind_frame_info *frame_info) { /* * synchronous unwinding (e.g. dump_stack) * - uses current values of SP and friends */ - if (tsk == NULL && regs == NULL) { + if (regs == NULL && (tsk == NULL || tsk == current)) { unsigned long fp, sp, blink, ret; frame_info->task = current;
@@ -66,11 +66,15 @@ static void seed_unwind_frame_info(struct task_struct *tsk, frame_info->call_frame = 0; } else if (regs == NULL) { /* - * Asynchronous unwinding of sleeping task - * - Gets SP etc from task's pt_regs (saved bottom of kernel - * mode stack of task) + * Asynchronous unwinding of a likely sleeping task + * - first ensure it is actually sleeping + * - if so, it will be in __switch_to, kernel mode SP of task + * is safe-kept and BLINK at a well known location in there */
+ if (tsk->state == TASK_RUNNING) + return -1; + frame_info->task = tsk;
frame_info->regs.r27 = TSK_K_FP(tsk); @@ -104,6 +108,8 @@ static void seed_unwind_frame_info(struct task_struct *tsk, frame_info->regs.r63 = regs->ret; frame_info->call_frame = 0; } + + return 0; }
#endif @@ -117,7 +123,8 @@ arc_unwind_core(struct task_struct *tsk, struct pt_regs *regs, unsigned int address; struct unwind_frame_info frame_info;
- seed_unwind_frame_info(tsk, regs, &frame_info); + if (seed_unwind_frame_info(tsk, regs, &frame_info)) + return 0;
while (1) { address = UNW_PC(&frame_info);
From: Yves-Alexis Perez corsac@corsac.net
[ Upstream commit f33d9e2b48a34e1558b67a473a1fc1d6e793f93c ]
Starting with iOS 14 released in September 2020, connectivity using the personal hotspot USB tethering function of iOS devices is broken.
Communication between the host and the device (for example ICMP traffic or DNS resolution using the DNS service running in the device itself) works fine, but communication to endpoints further away doesn't work.
Investigation on the matter shows that no UDP and ICMP traffic from the tethered host is reaching the Internet at all. For TCP traffic there are exchanges between tethered host and server but packets are modified in transit leading to impossible communication.
After some trials Matti Vuorela discovered that reducing the URB buffer size by two bytes restored the previous behavior. While a better solution might exist to fix the issue, since the protocol is not publicly documented and considering the small size of the fix, let's do that.
Tested-by: Matti Vuorela matti.vuorela@bitfactor.fi Signed-off-by: Yves-Alexis Perez corsac@corsac.net Link: https://lore.kernel.org/linux-usb/CAAn0qaXmysJ9vx3ZEMkViv_B19ju-_ExN8Yn_uSef... Link: https://github.com/libimobiledevice/libimobiledevice/issues/1038 Link: https://lore.kernel.org/r/20201119172439.94988-1-corsac@corsac.net Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/usb/ipheth.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/usb/ipheth.c b/drivers/net/usb/ipheth.c index 2b16a5fed9ded..0cf5324d493e8 100644 --- a/drivers/net/usb/ipheth.c +++ b/drivers/net/usb/ipheth.c @@ -70,7 +70,7 @@ #define IPHETH_USBINTF_SUBCLASS 253 #define IPHETH_USBINTF_PROTO 1
-#define IPHETH_BUF_SIZE 1516 +#define IPHETH_BUF_SIZE 1514 #define IPHETH_IP_ALIGN 2 /* padding at front of URB */ #define IPHETH_TX_TIMEOUT (5 * HZ)
From: Timo Witte timo.witte@gmail.com
[ Upstream commit 9e7a005ad56aa7d6ea5830c5ffcc60bf35de380b ]
Got a dmesg message on my AMD Renoir based Acer laptop: "acer_wmi: Unknown key number - 0x84" when toggling keyboard background light
Signed-off-by: Timo Witte timo.witte@gmail.com Reviewed-by: "Lee, Chun-Yi" jlee@suse.com Link: https://lore.kernel.org/r/20200804001423.36778-1-timo.witte@gmail.com Signed-off-by: Hans de Goede hdegoede@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/platform/x86/acer-wmi.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/drivers/platform/x86/acer-wmi.c b/drivers/platform/x86/acer-wmi.c index 1515c9480f89f..90015e2cce9bf 100644 --- a/drivers/platform/x86/acer-wmi.c +++ b/drivers/platform/x86/acer-wmi.c @@ -124,6 +124,7 @@ static const struct key_entry acer_wmi_keymap[] __initconst = { {KE_KEY, 0x64, {KEY_SWITCHVIDEOMODE} }, /* Display Switch */ {KE_IGNORE, 0x81, {KEY_SLEEP} }, {KE_KEY, 0x82, {KEY_TOUCHPAD_TOGGLE} }, /* Touch Pad Toggle */ + {KE_IGNORE, 0x84, {KEY_KBDILLUMTOGGLE} }, /* Automatic Keyboard background light toggle */ {KE_KEY, KEY_TOUCHPAD_ON, {KEY_TOUCHPAD_ON} }, {KE_KEY, KEY_TOUCHPAD_OFF, {KEY_TOUCHPAD_OFF} }, {KE_IGNORE, 0x83, {KEY_TOUCHPAD_TOGGLE} },
linux-stable-mirror@lists.linaro.org
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Sasha Levin