This is a note to let you know that I've just added the patch titled

drm/panel: Select DRM_DP_HELPER for DRM_PANEL_EDP

to the 5.16-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summ...

The filename of the patch is: drm-panel-select-drm_dp_helper-for-drm_panel_edp.patch and it can be found in the queue-5.16 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From 3755d35ee1d2454b20b8a1e20d790e56201678a4 Mon Sep 17 00:00:00 2001

From: Thomas Zimmermann tzimmermann@suse.de Date: Thu, 3 Feb 2022 10:39:22 +0100 Subject: drm/panel: Select DRM_DP_HELPER for DRM_PANEL_EDP

From: Thomas Zimmermann tzimmermann@suse.de

commit 3755d35ee1d2454b20b8a1e20d790e56201678a4 upstream.

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: 9d6366e743f3 ("drm: fb_helper: improve CONFIG_FB dependency") Reported-by: Naresh Kamboju naresh.kamboju@linaro.org Reported-by: Linux Kernel Functional Testing lkft@linaro.org Reviewed-by: Lyude Paul lyude@redhat.com Acked-by: Sam Ravnborg sam@ravnborg.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 Link: https://patchwork.freedesktop.org/patch/msgid/20220203093922.20754-1-tzimmer... Signed-off-by: Dave Airlie airlied@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/panel/Kconfig | 1 + 1 file changed, 1 insertion(+)

--- a/drivers/gpu/drm/panel/Kconfig +++ b/drivers/gpu/drm/panel/Kconfig @@ -95,6 +95,7 @@ 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

Patches currently in stable-queue which might be from tzimmermann@suse.de are

queue-5.16/drm-panel-select-drm_dp_helper-for-drm_panel_edp.patch