Hi Daniel, On 18/05/2020 21:16, Daniel Gomez wrote: > Select DRM_KMS_HELPER dependency. > > Build error when DRM_KMS_HELPER is not selected: > > drivers/gpu/drm/rcar-du/rcar_lvds.o:(.rodata+0xd48): undefined reference to > `drm_atomic_helper_bridge_duplicate_state' > drivers/gpu/drm/rcar-du/rcar_lvds.o:(.rodata+0xd50): undefined reference to > `drm_atomic_helper_bridge_destroy_state' > drivers/gpu/drm/rcar-du/rcar_lvds.o:(.rodata+0xd70): undefined reference to > `drm_atomic_helper_bridge_reset' > drivers/gpu/drm/rcar-du/rcar_lvds.o:(.rodata+0xdc8): undefined reference to > `drm_atomic_helper_connector_reset' > drivers/gpu/drm/rcar-du/rcar_lvds.o:(.rodata+0xde0): undefined reference to > `drm_helper_probe_single_connector_modes' > drivers/gpu/drm/rcar-du/rcar_lvds.o:(.rodata+0xe08): undefined reference to > `drm_atomic_helper_connector_duplicate_state' > drivers/gpu/drm/rcar-du/rcar_lvds.o:(.rodata+0xe10): undefined reference to > `drm_atomic_helper_connector_destroy_state' >
Looking at the files in rcar_du that utilise drm_atomic_helpers... git grep -l drm_atomic_helper_ drivers/gpu/drm/rcar-du/ drivers/gpu/drm/rcar-du/rcar_du_crtc.c drivers/gpu/drm/rcar-du/rcar_du_kms.c drivers/gpu/drm/rcar-du/rcar_du_plane.c drivers/gpu/drm/rcar-du/rcar_du_vsp.c drivers/gpu/drm/rcar-du/rcar_du_writeback.c drivers/gpu/drm/rcar-du/rcar_lvds.c of those, these are configurable: rcar_du_vsp.c # DRM_RCAR_VSP rcar_du_writeback.c # DRM_RCAR_WRITEBACK rcar_lvds.c # DRM_RCAR_LVDS But VSP and WRITEBACK are already implicitly dependant upon DRM_RCAR_DU because they get built into the DU module. So indeed, only the RCAR_LVDS is a separate module, using those helpers, so I think a select is a reasonable fix. I would also ask whether DRM_RCAR_LVDS should depend upon DRM_RCAR_DU though as well. There is no linkage requirement, as it's a standalone bridge driver from what I can see, but I don't think it serves much purpose without the DU? Anyway, even if it's just for compile testing maybe, the select here should be fine. Reviewed-by: Kieran Bingham <kieran.bingham+rene...@ideasonboard.com> > Signed-off-by: Daniel Gomez <dag...@gmail.com> > --- > drivers/gpu/drm/rcar-du/Kconfig | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/gpu/drm/rcar-du/Kconfig b/drivers/gpu/drm/rcar-du/Kconfig > index 0919f1f159a4..f65d1489dc50 100644 > --- a/drivers/gpu/drm/rcar-du/Kconfig > +++ b/drivers/gpu/drm/rcar-du/Kconfig > @@ -31,6 +31,7 @@ config DRM_RCAR_DW_HDMI > config DRM_RCAR_LVDS > tristate "R-Car DU LVDS Encoder Support" > depends on DRM && DRM_BRIDGE && OF > + select DRM_KMS_HELPER > select DRM_PANEL > select OF_FLATTREE > select OF_OVERLAY >
