On Tue, Mar 15, 2022 at 09:45:59AM +0100, Thomas Zimmermann wrote:
> Fix a number of undefined references to drm_kms_helper.ko in
> drm_dp_helper.ko:
>
> arm-suse-linux-gnueabi-ld: drivers/gpu/drm/dp/drm_dp_mst_topology.o: in function `drm_dp_mst_duplicate_state':
> drm_dp_mst_topology.c:(.text+0x2df0): undefined reference to `__drm_atomic_helper_private_obj_duplicate_state'
> arm-suse-linux-gnueabi-ld: drivers/gpu/drm/dp/drm_dp_mst_topology.o: in function `drm_dp_delayed_destroy_work':
> drm_dp_mst_topology.c:(.text+0x370c): undefined reference to `drm_kms_helper_hotplug_event'
> arm-suse-linux-gnueabi-ld: drivers/gpu/drm/dp/drm_dp_mst_topology.o: in function `drm_dp_mst_up_req_work':
> drm_dp_mst_topology.c:(.text+0x7938): undefined reference to `drm_kms_helper_hotplug_event'
> arm-suse-linux-gnueabi-ld: drivers/gpu/drm/dp/drm_dp_mst_topology.o: in function `drm_dp_mst_link_probe_work':
> drm_dp_mst_topology.c:(.text+0x82e0): undefined reference to `drm_kms_helper_hotplug_event'
>
> This happens if panel-edp.ko has been configured with
>
> DRM_PANEL_EDP=y
> DRM_DP_HELPER=y
> DRM_KMS_HELPER=m
>
> which builds DP helpers into the kernel and KMS helpers sa a module.
> Making DRM_PANEL_EDP select DRM_KMS_HELPER resolves this problem.
>
> To avoid a resulting cyclic dependency with DRM_PANEL_BRIDGE, don't
> make the latter depend on DRM_KMS_HELPER and fix the one DRM bridge
> drivers that doesn't already select DRM_KMS_HELPER. As KMS helpers
> cannot be selected directly by the user, config symbols should avoid
> depending on it anyway.
>
> Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
> Fixes: 3755d35ee1d2 ("drm/panel: Select DRM_DP_HELPER for DRM_PANEL_EDP")
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Cc: Thomas Zimmermann <tzimmermann@xxxxxxx>
> Cc: Naresh Kamboju <naresh.kamboju@xxxxxxxxxx>
> Cc: Linux Kernel Functional Testing <lkft@xxxxxxxxxx>
> Cc: Lyude Paul <lyude@xxxxxxxxxx>
> Cc: Sam Ravnborg <sam@xxxxxxxxxxxx>
> Cc: Daniel Vetter <daniel@xxxxxxxx>
> Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
> Cc: Maxime Ripard <mripard@xxxxxxxxxx>
> Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
> Cc: Dave Airlie <airlied@xxxxxxxxxx>
> Cc: Thierry Reding <thierry.reding@xxxxxxxxx>
Acked-by: Sam Ravnborg <sam@xxxxxxxxxxxx>
