Adapt drm_pick_crtcs() and update_connector_routing() to fallback to drm_atomic_helper_best_encoder() if funcs->best_encoder() is NULL so that DRM drivers can leave this hook unassigned if they know they want to use drm_atomic_helper_best_encoder(). Update the vtables documentation accordingly. Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/drm_atomic_helper.c | 4 +++- drivers/gpu/drm/drm_fb_helper.c | 13 ++++++++++++- include/drm/drm_modeset_helper_vtables.h | 10 ++++++++-- 3 files changed, 23 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c index f6a3350..849d029 100644 --- a/drivers/gpu/drm/drm_atomic_helper.c +++ b/drivers/gpu/drm/drm_atomic_helper.c @@ -300,8 +300,10 @@ update_connector_routing(struct drm_atomic_state *state, if (funcs->atomic_best_encoder) new_encoder = funcs->atomic_best_encoder(connector, connector_state); - else + else if (funcs->best_encoder) new_encoder = funcs->best_encoder(connector); + else + new_encoder = drm_atomic_helper_best_encoder(connector); if (!new_encoder) { DRM_DEBUG_ATOMIC("No suitable encoder found for [CONNECTOR:%d:%s]\n", diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index 7c2eb75..d44389a 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -2000,7 +2000,18 @@ static int drm_pick_crtcs(struct drm_fb_helper *fb_helper, my_score++; connector_funcs = connector->helper_private; - encoder = connector_funcs->best_encoder(connector); + + /* + * If the DRM device implements atomic hooks and ->best_encoder() is + * NULL we fallback to the default drm_atomic_helper_best_encoder() + * helper. + */ + if (fb_helper->dev->mode_config.funcs->atomic_commit && + !connector_funcs->best_encoder) + encoder = drm_atomic_helper_best_encoder(connector); + else + encoder = connector_funcs->best_encoder(connector); + if (!encoder) goto out; diff --git a/include/drm/drm_modeset_helper_vtables.h b/include/drm/drm_modeset_helper_vtables.h index d4619dc..4e7a53b 100644 --- a/include/drm/drm_modeset_helper_vtables.h +++ b/include/drm/drm_modeset_helper_vtables.h @@ -736,6 +736,11 @@ struct drm_connector_helper_funcs { * inspect dynamic configuration state should instead use * @atomic_best_encoder. * + * You can leave this function to NULL if the connector is only + * attached to a single encoder and you are using the atomic helpers. + * In this case, the core will call drm_atomic_helper_best_encoder() + * for you. + * * RETURNS: * * Encoder that should be used for the given connector and connector @@ -752,8 +757,9 @@ struct drm_connector_helper_funcs { * need to select the best encoder depending upon the desired * configuration and can't select it statically. * - * This function is used by drm_atomic_helper_check_modeset() and either - * this or @best_encoder is required. + * This function is used by drm_atomic_helper_check_modeset(). + * If it is not implemented, the core will fallback to @best_encoder + * (or drm_atomic_helper_best_encoder() if @best_encoder is NULL). * * NOTE: * -- 2.7.4