Re: [PATCH v2 1/2] drm/panel-edp: fix i2c adapter leak on probe failure

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:

Pre-existing issues:
- [High] The device can be left permanently powered on if the driver is unbound while an asynchronous autosuspend is pending.
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--- Patch [1]: [PATCH v2 1/2] drm/panel-edp: fix i2c adapter leak on probe failure ---
commit 471fbc83c1856bd9eec16a225d0ec84f3032c113
Author: Johan Hovold <johan@kernel.org>

drm/panel-edp: fix i2c adapter leak on probe failure

This commit fixes a reference leak on an i2c adapter during probe failure
or driver unbind. It introduces a devres action to automatically drop the
adapter reference, streamlining the cleanup path and removing manual puts.

Link: https://lore.kernel.org/r/CAD=FV=VZPhzHU+Pet2m3L+Pqc7mOPfZC-f5p0OuNL79wNZPxRg@mail.gmail.com

> diff --git a/drivers/gpu/drm/panel/panel-edp.c b/drivers/gpu/drm/panel/panel-edp.c
> index f66474d3ef65e..775bd6af31ae7 100644
> --- a/drivers/gpu/drm/panel/panel-edp.c
> +++ b/drivers/gpu/drm/panel/panel-edp.c

[ ... ]

> @@ -983,8 +992,6 @@ static void panel_edp_remove(struct device *dev)
>  
>  	pm_runtime_dont_use_autosuspend(dev);
>  	pm_runtime_disable(dev);

[Severity: High]
This is a pre-existing issue, but does this sequence leave the device
permanently powered on if unbound while an autosuspend is pending?

During probe, pm_runtime_get_sync() is followed by
pm_runtime_put_autosuspend() (e.g., in generic_edp_panel_probe()), leaving
the device in RPM_ACTIVE for 1000ms. If the driver is unbound before this
timer fires, pm_runtime_disable() cancels the pending autosuspend work
without suspending the device.

This can leave the panel regulators and GPIOs permanently enabled, and
trigger a kernel WARN_ON from devres during regulator_put() due to an
unbalanced enable count. Should there be a synchronous suspend call prior
to disabling runtime PM in the removal path?

> -	if (panel->ddc && (!panel->aux || panel->ddc != &panel->aux->ddc))
> -		put_device(&panel->ddc->dev);
>  
>  	drm_edid_free(panel->drm_edid);
>  	panel->drm_edid = NULL;

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260717143119.1815106-1-johan@kernel.org?part=1