On Wed, Nov 26, 2025 at 01:22:19PM +0100, Bartosz Golaszewski wrote:

From: Bartosz Golaszewski bartosz.golaszewski@linaro.org

The gpio_chip settings in this driver say the controller can't sleep but it actually uses a mutex for synchronization. This triggers the following BUG():

[ 9.233659] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:281 [ 9.233665] in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 554, name: (udev-worker) [ 9.233669] preempt_count: 1, expected: 0 [ 9.233673] RCU nest depth: 0, expected: 0 [ 9.233688] Tainted: [W]=WARN [ 9.233690] Hardware name: Dell Inc. Latitude 7455/0FK7MX, BIOS 2.10.1 05/20/2025 [ 9.233694] Call trace: [ 9.233696] show_stack+0x24/0x38 (C) [ 9.233709] dump_stack_lvl+0x40/0x88 [ 9.233716] dump_stack+0x18/0x24 [ 9.233722] __might_resched+0x148/0x160 [ 9.233731] __might_sleep+0x38/0x98 [ 9.233736] mutex_lock+0x30/0xd8

As far as I can see, this mutex only protects mmio accesses.

Is it preferable to mark the gpio chip can_sleep over replacing the mutex with a non-sleep lock?

[ 9.233749] lpi_config_set+0x2e8/0x3c8 [pinctrl_lpass_lpi] [ 9.233757] lpi_gpio_direction_output+0x58/0x90 [pinctrl_lpass_lpi] [ 9.233761] gpiod_direction_output_raw_commit+0x110/0x428 [ 9.233772] gpiod_direction_output_nonotify+0x234/0x358 [ 9.233779] gpiod_direction_output+0x38/0xd0 [ 9.233786] gpio_shared_proxy_direction_output+0xb8/0x2a8 [gpio_shared_proxy] [ 9.233792] gpiod_direction_output_raw_commit+0x110/0x428 [ 9.233799] gpiod_direction_output_nonotify+0x234/0x358 [ 9.233806] gpiod_configure_flags+0x2c0/0x580 [ 9.233812] gpiod_find_and_request+0x358/0x4f8 [ 9.233819] gpiod_get_index+0x7c/0x98 [ 9.233826] devm_gpiod_get+0x34/0xb0 [ 9.233829] reset_gpio_probe+0x58/0x128 [reset_gpio] [ 9.233836] auxiliary_bus_probe+0xb0/0xf0 [ 9.233845] really_probe+0x14c/0x450 [ 9.233853] __driver_probe_device+0xb0/0x188 [ 9.233858] driver_probe_device+0x4c/0x250 [ 9.233863] __driver_attach+0xf8/0x2a0 [ 9.233868] bus_for_each_dev+0xf8/0x158 [ 9.233872] driver_attach+0x30/0x48 [ 9.233876] bus_add_driver+0x158/0x2b8 [ 9.233880] driver_register+0x74/0x118 [ 9.233886] __auxiliary_driver_register+0x94/0xe8 [ 9.233893] init_module+0x34/0xfd0 [reset_gpio] [ 9.233898] do_one_initcall+0xec/0x300 [ 9.233903] do_init_module+0x64/0x260 [ 9.233910] load_module+0x16c4/0x1900 [ 9.233915] __arm64_sys_finit_module+0x24c/0x378 [ 9.233919] invoke_syscall+0x4c/0xe8 [ 9.233925] el0_svc_common+0x8c/0xf0 [ 9.233929] do_el0_svc+0x28/0x40 [ 9.233934] el0_svc+0x38/0x100 [ 9.233938] el0t_64_sync_handler+0x84/0x130 [ 9.233943] el0t_64_sync+0x17c/0x180

Mark the controller as sleeping.

Fixes: 6e261d1090d6 ("pinctrl: qcom: Add sm8250 lpass lpi pinctrl driver") Cc: stable@vger.kernel.org Reported-by: Val Packett val@packett.cool Closes: https://lore.kernel.org/all/98c0f185-b0e0-49ea-896c-f3972dd011ca@packett.coo... Signed-off-by: Bartosz Golaszewski bartosz.golaszewski@linaro.org

If we stick to the mutex, the patch LGTM

Reviewed-by: Bjorn Andersson andersson@kernel.org

Regards, Bjorn

---

drivers/pinctrl/qcom/pinctrl-lpass-lpi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pinctrl/qcom/pinctrl-lpass-lpi.c b/drivers/pinctrl/qcom/pinctrl-lpass-lpi.c index 1c97ec44aa5ff..78212f9928430 100644 --- a/drivers/pinctrl/qcom/pinctrl-lpass-lpi.c +++ b/drivers/pinctrl/qcom/pinctrl-lpass-lpi.c @@ -498,7 +498,7 @@ int lpi_pinctrl_probe(struct platform_device *pdev) pctrl->chip.base = -1; pctrl->chip.ngpio = data->npins; pctrl->chip.label = dev_name(dev);

• pctrl->chip.can_sleep = false;

• pctrl->chip.can_sleep = true;

mutex_init(&pctrl->lock); -- 2.51.0