On Wed, Jun 18, 2025 at 6:21 PM Mark Brown [off-list ref] wrote:

On Tue, Jun 10, 2025 at 02:33:11PM +0200, Bartosz Golaszewski wrote:

quoted

From: Bartosz Golaszewski <redacted>

struct gpio_chip now has callbacks for setting line values that return
an integer, allowing to indicate failures. Convert the driver to using
them.

I'm seeing boot failures on a UDOOq (an i.MX6 based board) in -next
today which bisect to this patch (in -next as b908d35d0003cc7).  We get
a NULL pointer dereference during boot while probing the poweroff driver
for the system:

[    0.443319] Unable to handle kernel NULL pointer dereference at virtual address 00000000 when execute
[    0.443330] [00000000] *pgd=00000000
[    0.443347] Internal error: Oops: 80000005 [#2] SMP ARM

...

[    2.522761]  bgpio_dir_out_val_first from gpiod_direction_output_raw_commit+0x194/0x390
[    2.533330]  gpiod_direction_output_raw_commit from gpiod_find_and_request+0x134/0x434
[    2.541276]  gpiod_find_and_request from gpiod_get_index+0x58/0x70
[    2.547482]  gpiod_get_index from devm_gpiod_get_index+0x10/0x78
[    2.553516]  devm_gpiod_get_index from gpio_poweroff_probe+0xe8/0x174
[    2.559990]  gpio_poweroff_probe from platform_probe+0x5c/0xb4

Thanks, a patch[1] is already up for review. Please give it a try and
leave your Tested-by: if you can.

Bartosz

[1] https://lore.kernel.org/all/20250618-gpio-mmio-fix-setter-v1-2-2578ffb77019@linaro.org/ (local)