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@suse.de 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@linaro.org Reported-by: Linux Kernel Functional Testing lkft@linaro.org Link: https://lore.kernel.org/dri-devel/CA+G9fYvN0NyaVkRQmA1O6rX7H8PPaZrUAD7=RDy33... # [1] Link: https://lore.kernel.org/all/20211117062704.14671-1-rdunlap@infradead.org/ # [2] Cc: Thomas Zimmermann tzimmermann@suse.de Cc: Lyude Paul lyude@redhat.com Cc: Daniel Vetter daniel@ffwll.ch Cc: Maarten Lankhorst maarten.lankhorst@linux.intel.com Cc: Maxime Ripard mripard@kernel.org Cc: dri-devel@lists.freedesktop.org --- 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