From 2f196b7c4b82eeff3574eb2999e78add33ef4361 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Thu, 2 Jun 2016 16:21:44 +0200 Subject: drm/atomic: Add drm_atomic_crtc_state_for_each_plane_state ... and use it in msm&vc4. Again just want to encapsulate drm_atomic_state internals a bit. The const threading is a bit awkward in vc4 since C sucks, but I still think it's worth to enforce this. Eventually I want to make all the obj->state pointers const too, but that's a lot more work ... v2: Provide safe macro to wrap up the unsafe helper better, suggested by Maarten. v3: Fixup subject (Maarten) and spelling fixes (Eric Engestrom). Cc: Eric Anholt Cc: Rob Clark Cc: Maarten Lankhorst Cc: Eric Engestrom Reviewed-by: Maarten Lankhorst Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/1464877304-4213-1-git-send-email-daniel.vetter@ffwll.ch --- include/drm/drm_atomic.h | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) (limited to 'include/drm/drm_atomic.h') diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h index 92c84e9ab09a..4e97186293be 100644 --- a/include/drm/drm_atomic.h +++ b/include/drm/drm_atomic.h @@ -109,6 +109,42 @@ drm_atomic_get_existing_connector_state(struct drm_atomic_state *state, return state->connector_states[index]; } +/** + * __drm_atomic_get_current_plane_state - get current plane state + * @state: global atomic state object + * @plane: plane to grab + * + * This function returns the plane state for the given plane, either from + * @state, or if the plane isn't part of the atomic state update, from @plane. + * This is useful in atomic check callbacks, when drivers need to peek at, but + * not change, state of other planes, since it avoids threading an error code + * back up the call chain. + * + * WARNING: + * + * Note that this function is in general unsafe since it doesn't check for the + * required locking for access state structures. Drivers must ensure that it is + * save to access the returned state structure through other means. One commone + * example is when planes are fixed to a single CRTC, and the driver knows that + * the CRTC locks is held already. In that case holding the CRTC locks gives a + * read-lock on all planes connected to that CRTC. But if planes can be + * reassigned things get more tricky. In that case it's better to use + * drm_atomic_get_plane_state and wire up full error handling. + * + * Returns: + * + * Read-only pointer to the current plane state. + */ +static inline const struct drm_plane_state * +__drm_atomic_get_current_plane_state(struct drm_atomic_state *state, + struct drm_plane *plane) +{ + if (state->plane_states[drm_plane_index(plane)]) + return state->plane_states[drm_plane_index(plane)]; + + return plane->state; +} + int __must_check drm_atomic_set_mode_for_crtc(struct drm_crtc_state *state, struct drm_display_mode *mode); -- cgit v1.2.3