drm: atomic: Clarify documentation around drm_atomic_crtc_needs_modeset (d807ed1c) · Commits · 戴 / test

drivers/gpu/drm/drm_atomic_helper.c

+5 −4

Original line number	Diff line number	Diff line
		@@ -458,10 +458,11 @@ mode_fixup(struct drm_atomic_state *state)
		* removed from the crtc.
		* crtc_state->active_changed is set when crtc_state->active changes,
		* which is used for dpms.
		* See also: drm_atomic_crtc_needs_modeset()
		*
		* IMPORTANT:
		*
		* Drivers which update ->mode_changed (e.g. in their ->atomic_check hooks if a
		* Drivers which set ->mode_changed (e.g. in their ->atomic_check hooks if a
		* plane update can't be done without a full modeset) _must_ call this function
		* afterwards after that change. It is permitted to call this function multiple
		* times for the same update, e.g. when the ->atomic_check functions depend upon
		@@ -510,9 +511,9 @@ drm_atomic_helper_check_modeset(struct drm_device *dev,

		for_each_connector_in_state(state, connector, connector_state, i) {
		/*
		* This only sets crtc->mode_changed for routing changes,
		* drivers must set crtc->mode_changed themselves when connector
		* properties need to be updated.
		* This only sets crtc->connectors_changed for routing changes,
		* drivers must set crtc->connectors_changed themselves when
		* connector properties need to be updated.
		*/
		ret = update_connector_routing(state, connector,
		connector_state);

+10 −1

Original line number	Diff line number	Diff line
		@@ -365,8 +365,17 @@ int __must_check drm_atomic_nonblocking_commit(struct drm_atomic_state *state);
		*
		* To give drivers flexibility struct &drm_crtc_state has 3 booleans to track
		* whether the state CRTC changed enough to need a full modeset cycle:
		* connectors_changed, mode_changed and active_change. This helper simply
		* connectors_changed, mode_changed and active_changed. This helper simply
		* combines these three to compute the overall need for a modeset for @state.
		*
		* The atomic helper code sets these booleans, but drivers can and should
		* change them appropriately to accurately represent whether a modeset is
		* really needed. In general, drivers should avoid full modesets whenever
		* possible.
		*
		* For example if the CRTC mode has changed, and the hardware is able to enact
		* the requested mode change without going through a full modeset, the driver
		* should clear mode_changed during its ->atomic_check.
		*/
		static inline bool
		drm_atomic_crtc_needs_modeset(struct drm_crtc_state *state)

+5 −0

Original line number	Diff line number	Diff line
		@@ -116,6 +116,11 @@ struct drm_plane_helper_funcs;
		* never return in a failure from the ->atomic_check callback. Userspace assumes
		* that a DPMS On will always succeed. In other words: @enable controls resource
		* assignment, @active controls the actual hardware state.
		*
		* The three booleans active_changed, connectors_changed and mode_changed are
		* intended to indicate whether a full modeset is needed, rather than strictly
		* describing what has changed in a commit.
		* See also: drm_atomic_crtc_needs_modeset()
		*/
		struct drm_crtc_state {
		struct drm_crtc *crtc;