[PATCH weston v5 04/42] Remove DPMS-on when going offscreen

[Daniel Stone]

Forcing DPMS on when we lose our session may force an expensive modeset
operation, which is pointless if the next consumer (another compositor,
or the console) is going to do a modeset. These should force DPMS on
regardless.

This actively causes problems for the DRM backend, in that it may
actually require a repaint to set coherent state for DPMS off -> DPMS on
transitions, which is very much not what we want when going offscreen.

As DRM is the only backend which actually implements DPMS, just remove
this call.

Signed-off-by: Daniel Stone <daniels at collabora.com>

Differential Revision: https://phabricator.freedesktop.org/D1483
---
 libweston/compositor.c | 9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/libweston/compositor.c b/libweston/compositor.c
index d552e18..c403bfa 100644
--- a/libweston/compositor.c
+++ b/libweston/compositor.c
@@ -3940,10 +3940,9 @@ weston_compositor_wake(struct weston_compositor *compositor)
 
 	switch (old_state) {
 	case WESTON_COMPOSITOR_SLEEPING:
-		weston_compositor_dpms(compositor, WESTON_DPMS_ON);
-		/* fall through */
 	case WESTON_COMPOSITOR_IDLE:
 	case WESTON_COMPOSITOR_OFFSCREEN:
+		weston_compositor_dpms(compositor, WESTON_DPMS_ON);
 		wl_signal_emit(&compositor->wake_signal, compositor);
 		/* fall through */
 	default:
@@ -3959,10 +3958,6 @@ weston_compositor_wake(struct weston_compositor *compositor)
  * This is used for example to prevent further rendering while the
  * compositor is shutting down.
  *
- * \note When offscreen state is entered, outputs will be powered
- * back on if they were sleeping (in DPMS off mode), even though
- * no rendering will be performed.
- *
  * Stops the idle timer.
  */
 WL_EXPORT void
@@ -3972,8 +3967,6 @@ weston_compositor_offscreen(struct weston_compositor *compositor)
 	case WESTON_COMPOSITOR_OFFSCREEN:
 		return;
 	case WESTON_COMPOSITOR_SLEEPING:
-		weston_compositor_dpms(compositor, WESTON_DPMS_ON);
-		/* fall through */
 	default:
 		compositor->state = WESTON_COMPOSITOR_OFFSCREEN;
 		wl_event_source_timer_update(compositor->idle_source, 0);
-- 
2.9.3