diff options
| author | Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com> | 2026-05-22 11:12:37 +0200 |
|---|---|---|
| committer | Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com> | 2026-05-28 15:23:40 +0200 |
| commit | 9d7697fabbc72428f981c01ddbe0a6be0ce8b6fa (patch) | |
| tree | 493fe2323a5bb8d48157d86eb8f8750437c9b785 | |
| parent | a1b836607304f71051f9f9dcccf8b5097b86a1fb (diff) | |
gpio: shared: fix lockdep false positive by removing unneeded lock
By the time gpio_device_teardown_shared() is called, the parent device
is gone from the global list of GPIO devices and all outstanding SRCU
read-side critical sections have completed. That means that no
concurrent gpio_find_and_request() can call
gpio_shared_add_proxy_lookup() for this device at this time. There's
also no risk of the parent device being re-bound to the driver before
the unbinding completes (including the child devices).
Lockdep produces a false-positive report about a possible circular
dependency as it doesn't know the ordering guarantee. Not taking the
ref->lock in gpio_device_teardown_shared() silences it and is safe to do.
Cc: stable@vger.kernel.org
Fixes: ea513dd3c066 ("gpio: shared: make locking more fine-grained")
Reviewed-by: Linus Walleij <linusw@kernel.org>
Link: https://patch.msgid.link/20260522-gpio-shared-deadlock-v1-2-76bca088f8c0@oss.qualcomm.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
| -rw-r--r-- | drivers/gpio/gpiolib-shared.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/drivers/gpio/gpiolib-shared.c b/drivers/gpio/gpiolib-shared.c index 087b64c06c9f..de72776fb154 100644 --- a/drivers/gpio/gpiolib-shared.c +++ b/drivers/gpio/gpiolib-shared.c @@ -605,8 +605,6 @@ void gpio_device_teardown_shared(struct gpio_device *gdev) gpiod_free_commit(&gdev->descs[entry->offset]); list_for_each_entry(ref, &entry->refs, list) { - guard(mutex)(&ref->lock); - if (ref->lookup) { gpiod_remove_lookup_table(ref->lookup); kfree(ref->lookup->table[0].key); |