Brought up by both Laurent and Andrzej when reviewing the new ->mode_valid hooks. Since mode_fixup is just a simpler version of the much more generic atomic_check we can't really unify it with mode_valid. Most drivers should probably switch their current mode_fixup code to either the new mode_valid or the atomic_check hooks, but e.g. that doesn't exist yet for bridges, and for CRTCs the situation is a bit more complicated. Hence there's no clear equivalence between mode_fixup and mode_valid, even if it looks like that at first glance. Cc: Andrzej Hajda <a.hajda@xxxxxxxxxxx> Cc: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> Cc: Jose Abreu <Jose.Abreu@xxxxxxxxxxxx> Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx> --- include/drm/drm_modeset_helper_vtables.h | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/include/drm/drm_modeset_helper_vtables.h b/include/drm/drm_modeset_helper_vtables.h index c72fca544a41..613b2a602b77 100644 --- a/include/drm/drm_modeset_helper_vtables.h +++ b/include/drm/drm_modeset_helper_vtables.h @@ -156,7 +156,11 @@ struct drm_crtc_helper_funcs { * allowed. * * Atomic drivers which need to inspect and adjust more state should - * instead use the @atomic_check callback. + * instead use the @atomic_check callback, but note that they're not + * perfectly equivalent: @mode_valid is called from + * drm_atomic_helper_check_modeset(), but @atomic_check is called from + * drm_atomic_helper_check_planes(), because originally it was meant for + * plane update checks only.. * * Also beware that userspace can request its own custom modes, neither * core nor helpers filter modes to the list of probe modes reported by @@ -529,7 +533,9 @@ struct drm_encoder_helper_funcs { * allowed. * * Atomic drivers which need to inspect and adjust more state should - * instead use the @atomic_check callback. + * instead use the @atomic_check callback. If @atomic_check is used, + * this hook isn't called since @atomic_check allows a strict superset + * of the functionality of @mode_fixup. * * Also beware that userspace can request its own custom modes, neither * core nor helpers filter modes to the list of probe modes reported by @@ -716,6 +722,11 @@ struct drm_encoder_helper_funcs { * update the CRTC to match what the encoder needs for the requested * connector. * + * Since this provides a strict superset of the functionality of + * @mode_fixup (the requested and adjusted modes are both available + * through the passed in &struct drm_crtc_state) @mode_fixup is not + * called when @atomic_check is implemented. + * * This function is used by the atomic helpers, but it is optional. * * NOTE: -- 2.11.0 _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel