Re: [PATCH v2 5/5] Input: hynitron-cst816x: power sequence with the panel

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] kconfig: built-in driver links to module due to incomplete DRM_PANEL dependency
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commit 334717615b8688937194889ec9606ffff8c712fd
Author: Daniel Golle <daniel@makrotopia.org>

Input: hynitron-cst816x: power sequence with the panel
    
Boards which mount the controller on the panel feed it from the
panel's rail, where a reset and the first interrupts are only
meaningful once the panel is powered. Register as a DRM panel follower
when the device tree points at a panel, so that the reset stays
asserted and the interrupt masked until the panel is prepared, and a
pressed key is released before the panel goes down again.

> diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
> index 9b9ae8ac3f7fd..0beb499e24f20 100644
> --- a/drivers/input/touchscreen/Kconfig
> +++ b/drivers/input/touchscreen/Kconfig
> @@ -478,6 +478,8 @@ config TOUCHSCREEN_HYNITRON_CSTXXX
>  config TOUCHSCREEN_HYNITRON_CST816X
>  	tristate "Hynitron CST816x touchscreen"
>  	depends on I2C
> +	# We call into panel code, so if DRM=m, this can't be 'y'
> +	depends on DRM || !DRM

[Severity: Low]
Does this allow a configuration where the driver is built-in but links to a
module?

The driver relies on devm_drm_panel_add_follower() from the drm_panel
framework. If DRM=y but DRM_PANEL=m, and TOUCHSCREEN_HYNITRON_CST816X=y, the
built-in touchscreen driver will have an unresolved external reference to
devm_drm_panel_add_follower() in drm_panel.ko, causing a build linking
failure.

Should this dependency be tied directly to DRM_PANEL instead, such as
depends on DRM_PANEL || !DRM_PANEL?

>  	help
>  	  Say Y here if you have a touchscreen using a Hynitron
>  	  CST816x series touchscreen controller.

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Sashiko AI review · https://sashiko.dev/#/patchset/cover.1790944534.git.daniel@makrotopia.org?part=5