[PATCH] ASoC: mediatek: mt8186: Fix mutex double unlock in GPIO request

[Mark Brown]

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