[PATCH] ASoC: mediatek: mt8186: Fix mutex double unlock in GPIO request
The lockdep mechanism reveals an unbalanced unlocking on MT8186:
[ 2.993966] WARNING: bad unlock balance detected! [ 2.993971] 5.15.46-421fef3b44d7-lockdep #16 Not tainted [ 2.993978] ------------------------------------- [ 2.993983] kworker/u16:1/10 is trying to release lock (gpio_request_mutex) at: [ 2.993994] [<ffffffdcd9adebf8>] mt8186_afe_gpio_request+0xf8/0x210 [ 2.994012] but there are no more locks to release! [ 2.994017] [ 2.994017] other info that might help us debug this: [ 2.994022] 3 locks held by kworker/u16:1/10: [ 2.994028] #0: ffffff80c004a148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1a8/0x364 [ 2.994054] #1: ffffffc0080d3d58 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work+0x1d0/0x364 [ 2.994074] #2: ffffff80c12ab9a0 (&dev->mutex){....}-{3:3}, at: __device_attach+0x44/0x150 [ 2.994096] [ 2.994096] stack backtrace: [ 2.994102] CPU: 6 PID: 10 Comm: kworker/u16:1 Not tainted 5.15.46-421fef3b44d7-lockdep #16 a2af0e2c6b3eeab6799b5aa8091c1d05d3a7bbb1 [ 2.994113] Hardware name: Google Kingler board (DT) [ 2.994120] Workqueue: events_unbound deferred_probe_work_func [ 2.994130] Call trace: [ 2.994135] dump_backtrace+0x0/0x1d4 [ 2.994144] show_stack+0x20/0x2c [ 2.994152] dump_stack_lvl+0x78/0x9c [ 2.994163] dump_stack+0x18/0x44 [ 2.994172] print_unlock_imbalance_bug+0xf0/0xf4 [ 2.994184] lock_release+0x150/0x388 [ 2.994193] __mutex_unlock_slowpath+0x4c/0x1bc [ 2.994202] mutex_unlock+0x44/0x50 [ 2.994210] mt8186_afe_gpio_request+0xf8/0x210 [ 2.994220] mt8186_afe_gpio_init+0xcc/0x134 [ 2.994230] mt8186_mt6366_rt1019_rt5682s_dev_probe+0x14c/0x220 [ 2.994238] platform_probe+0xb0/0xd0 [ 2.994247] really_probe+0xcc/0x2c8 [ 2.994253] __driver_probe_device+0xbc/0xe8 [ 2.994264] driver_probe_device+0x48/0xf0 [ 2.994271] __device_attach_driver+0xa0/0xc8 [ 2.994278] bus_for_each_drv+0x8c/0xd8 [ 2.994288] __device_attach+0xc4/0x150 [ 2.994298] device_initial_probe+0x1c/0x28 [ 2.994308] bus_probe_device+0x3c/0xa0 [ 2.994318] deferred_probe_work_func+0xa0/0xe0 [ 2.994325] process_one_work+0x208/0x364 [ 2.994334] worker_thread+0x288/0x3fc [ 2.994343] kthread+0x140/0x160 [ 2.994351] ret_from_fork+0x10/0x20
The cause is that the mutex will be double unlocked if dai is unknown during GPIO selection, and this patch fixes it.
Fixes: cfa9a966f12a ("ASoC: mediatek: mt8186: support gpio control in platform driver")
Signed-off-by: Fei Shao fshao@chromium.org ---
sound/soc/mediatek/mt8186/mt8186-afe-gpio.c | 1 - 1 file changed, 1 deletion(-)
diff --git a/sound/soc/mediatek/mt8186/mt8186-afe-gpio.c b/sound/soc/mediatek/mt8186/mt8186-afe-gpio.c index 255ffba637d3..274c0c8ec2f2 100644 --- a/sound/soc/mediatek/mt8186/mt8186-afe-gpio.c +++ b/sound/soc/mediatek/mt8186/mt8186-afe-gpio.c @@ -230,7 +230,6 @@ int mt8186_afe_gpio_request(struct device *dev, bool enable, sel = enable ? MT8186_AFE_GPIO_PCM_ON : MT8186_AFE_GPIO_PCM_OFF; break; default: - mutex_unlock(&gpio_request_mutex); dev_err(dev, "%s(), invalid dai %d\n", __func__, dai); goto unlock; }
On Fri, Jun 17, 2022 at 06:06:33PM +0800, Fei Shao wrote:
The lockdep mechanism reveals an unbalanced unlocking on MT8186:
[ 2.993966] WARNING: bad unlock balance detected! [ 2.993971] 5.15.46-421fef3b44d7-lockdep #16 Not tainted [ 2.993978] ------------------------------------- [ 2.993983] kworker/u16:1/10 is trying to release lock (gpio_request_mutex) at: [ 2.993994] [<ffffffdcd9adebf8>] mt8186_afe_gpio_request+0xf8/0x210 [ 2.994012] but there are no more locks to release! [ 2.994017] [ 2.994017] other info that might help us debug this:
Please think hard before including complete backtraces in upstream reports, they are very large and contain almost no useful information relative to their size so often obscure the relevant content in your message. If part of the backtrace is usefully illustrative (it often is for search engines if nothing else) then it's usually better to pull out the relevant sections.
On Fri, Jun 17, 2022 at 6:43 PM Mark Brown broonie@kernel.org wrote:
On Fri, Jun 17, 2022 at 06:06:33PM +0800, Fei Shao wrote:
The lockdep mechanism reveals an unbalanced unlocking on MT8186:
[ 2.993966] WARNING: bad unlock balance detected! [ 2.993971] 5.15.46-421fef3b44d7-lockdep #16 Not tainted [ 2.993978] ------------------------------------- [ 2.993983] kworker/u16:1/10 is trying to release lock (gpio_request_mutex) at: [ 2.993994] [<ffffffdcd9adebf8>] mt8186_afe_gpio_request+0xf8/0x210 [ 2.994012] but there are no more locks to release! [ 2.994017] [ 2.994017] other info that might help us debug this:
Please think hard before including complete backtraces in upstream reports, they are very large and contain almost no useful information relative to their size so often obscure the relevant content in your message. If part of the backtrace is usefully illustrative (it often is for search engines if nothing else) then it's usually better to pull out the relevant sections.
Agreed, I'll resend the patch. Thank you for the feedback.
Regards, Fei
On Fri, 17 Jun 2022 18:06:33 +0800, Fei Shao wrote:
The lockdep mechanism reveals an unbalanced unlocking on MT8186:
[ 2.993966] WARNING: bad unlock balance detected! [ 2.993971] 5.15.46-421fef3b44d7-lockdep #16 Not tainted [ 2.993978] ------------------------------------- [ 2.993983] kworker/u16:1/10 is trying to release lock (gpio_request_mutex) at: [ 2.993994] [<ffffffdcd9adebf8>] mt8186_afe_gpio_request+0xf8/0x210 [ 2.994012] but there are no more locks to release! [ 2.994017] [ 2.994017] other info that might help us debug this: [ 2.994022] 3 locks held by kworker/u16:1/10: [ 2.994028] #0: ffffff80c004a148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1a8/0x364 [ 2.994054] #1: ffffffc0080d3d58 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work+0x1d0/0x364 [ 2.994074] #2: ffffff80c12ab9a0 (&dev->mutex){....}-{3:3}, at: __device_attach+0x44/0x150 [ 2.994096] [ 2.994096] stack backtrace: [ 2.994102] CPU: 6 PID: 10 Comm: kworker/u16:1 Not tainted 5.15.46-421fef3b44d7-lockdep #16 a2af0e2c6b3eeab6799b5aa8091c1d05d3a7bbb1 [ 2.994113] Hardware name: Google Kingler board (DT) [ 2.994120] Workqueue: events_unbound deferred_probe_work_func [ 2.994130] Call trace: [ 2.994135] dump_backtrace+0x0/0x1d4 [ 2.994144] show_stack+0x20/0x2c [ 2.994152] dump_stack_lvl+0x78/0x9c [ 2.994163] dump_stack+0x18/0x44 [ 2.994172] print_unlock_imbalance_bug+0xf0/0xf4 [ 2.994184] lock_release+0x150/0x388 [ 2.994193] __mutex_unlock_slowpath+0x4c/0x1bc [ 2.994202] mutex_unlock+0x44/0x50 [ 2.994210] mt8186_afe_gpio_request+0xf8/0x210 [ 2.994220] mt8186_afe_gpio_init+0xcc/0x134 [ 2.994230] mt8186_mt6366_rt1019_rt5682s_dev_probe+0x14c/0x220 [ 2.994238] platform_probe+0xb0/0xd0 [ 2.994247] really_probe+0xcc/0x2c8 [ 2.994253] __driver_probe_device+0xbc/0xe8 [ 2.994264] driver_probe_device+0x48/0xf0 [ 2.994271] __device_attach_driver+0xa0/0xc8 [ 2.994278] bus_for_each_drv+0x8c/0xd8 [ 2.994288] __device_attach+0xc4/0x150 [ 2.994298] device_initial_probe+0x1c/0x28 [ 2.994308] bus_probe_device+0x3c/0xa0 [ 2.994318] deferred_probe_work_func+0xa0/0xe0 [ 2.994325] process_one_work+0x208/0x364 [ 2.994334] worker_thread+0x288/0x3fc [ 2.994343] kthread+0x140/0x160 [ 2.994351] ret_from_fork+0x10/0x20
[...]
Applied to
https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next
Thanks!
[1/1] ASoC: mediatek: mt8186: Fix mutex double unlock in GPIO request commit: 6c9e9046e1ff356bda66661213735d33c6cfea53
All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted.
You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed.
If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced.
Please add any relevant lists and maintainers to the CCs when replying to this mail.
Thanks, Mark
participants (2)
-
Fei Shao -
Mark Brown