Hi Thomas, On Thu, 3 Feb 2022 at 15:09, Thomas Zimmermann <tzimmermann@xxxxxxx> 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 Tested-by: Naresh Kamboju <naresh.kamboju@xxxxxxxxxx> Tested-by: Linux Kernel Functional Testing <lkft@xxxxxxxxxx> This patch fixes the repored build problem. > --- > 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 > -- Linaro LKFT https://lkft.linaro.org