diff options
| -rw-r--r-- | include/drm/drm_modeset_helper_vtables.h | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/include/drm/drm_modeset_helper_vtables.h b/include/drm/drm_modeset_helper_vtables.h index 361240ca738e..85984b208218 100644 --- a/include/drm/drm_modeset_helper_vtables.h +++ b/include/drm/drm_modeset_helper_vtables.h @@ -165,7 +165,11 @@ 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 @@ -547,7 +551,9 @@ 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 @@ -734,6 +740,11 @@ 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: |