On Thu, Feb 03, 2022 at 10:39:22AM +0100, Thomas Zimmermann wrote:
> As reported in [1], DRM_PANEL_EDP depends on DRM_DP_HELPER. Select
> the option to fix the build failure. The error message is shown
> below.
>
> arm-linux-gnueabihf-ld: drivers/gpu/drm/panel/panel-edp.o: in function
> `panel_edp_probe': panel-edp.c:(.text+0xb74): undefined reference to
> `drm_panel_dp_aux_backlight'
> make[1]: *** [/builds/linux/Makefile:1222: vmlinux] Error 1
>
> The issue has been reported before, when DisplayPort helpers were
> hidden behind the option CONFIG_DRM_KMS_HELPER. [2]
>
> v2:
> * fix and expand commit description (Arnd)
>
> Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
> Fixes: adb9d5a2cc77 ("drm/dp: Move DisplayPort helpers into separate helper module")
> Fixes: 5f04e7ce392d ("drm/panel-edp: Split eDP panels out of panel-simple")
> Reported-by: Naresh Kamboju <naresh.kamboju@xxxxxxxxxx>
> Reported-by: Linux Kernel Functional Testing <lkft@xxxxxxxxxx>
> Link: https://lore.kernel.org/dri-devel/CA+G9fYvN0NyaVkRQmA1O6rX7H8PPaZrUAD7=RDy33QY9rUU-9g@xxxxxxxxxxxxxx/ # [1]
> Link: https://lore.kernel.org/all/20211117062704.14671-1-rdunlap@xxxxxxxxxxxxx/ # [2]
> Cc: Thomas Zimmermann <tzimmermann@xxxxxxx>
> Cc: Lyude Paul <lyude@xxxxxxxxxx>
> Cc: Daniel Vetter <daniel@xxxxxxxx>
> Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
> Cc: Maxime Ripard <mripard@xxxxxxxxxx>
> Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
Acked-by: Sam Ravnborg <sam@xxxxxxxxxxxx>
> ---
> drivers/gpu/drm/panel/Kconfig | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
> index 434c2861bb40..0aec5a10b064 100644
> --- a/drivers/gpu/drm/panel/Kconfig
> +++ b/drivers/gpu/drm/panel/Kconfig
> @@ -106,6 +106,7 @@ config DRM_PANEL_EDP
> depends on PM
> select VIDEOMODE_HELPERS
> select DRM_DP_AUX_BUS
> + select DRM_DP_HELPER
> help
> DRM panel driver for dumb eDP panels that need at most a regulator and
> a GPIO to be powered up. Optionally a backlight can be attached so
> --
> 2.34.1
