[PATCH 01/12] gpio: mmio: use new GPIO line value setter callbacks

[Bartosz Golaszewski]

On Wed, Jun 18, 2025 at 6:21 PM Mark Brown <broonie at kernel.org> wrote:
>
> On Tue, Jun 10, 2025 at 02:33:11PM +0200, Bartosz Golaszewski wrote:
> > From: Bartosz Golaszewski <bartosz.golaszewski at linaro.org>
> >
> > 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/