Re: [PATCH] gpio: sysfs: fix chip removal with GPIOs exported over sysfs

[Bartosz Golaszewski]

On Fri, 13 Feb 2026 09:32:47 +0100, Johan Hovold <johan@xxxxxxxxxx> said:
> On Thu, Feb 12, 2026 at 02:35:05PM +0100, Bartosz Golaszewski wrote:
>> Currently if we export a GPIO over sysfs and unbind the parent GPIO
>> controller, the exported attribute will remain under /sys/class/gpio
>> because once we remove the parent device, we can no longer associate the
>> descriptor with it in gpiod_unexport() and never drop the final
>> reference.
>
> Is this a recent regression? I'm quite sure fixed this once back in
> 2015.
>

Yes, that sometimes happens. There have been close to 100 commits between your
fix and now, including two major reworks.

>> Rework the teardown code: provide an unlocked variant of
>> gpiod_unexport() and remove all exported GPIOs with the sysfs_lock taken
>> before unregistering the parent device itself. This is done to prevent
>> any new exports happening before we unregister the device completely.
>
> So please add a Fixes tag here to document this.
>
>> Cc: stable@xxxxxxxxxxxxxxx
>> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxxxxxxxx>
>
> Johan
>

It bisects to this commit, though it's possible it's a mix of several changes.

Fixes: 1cd53df733c2 ("gpio: sysfs: don't look up exported lines as
class devices")

Bartosz