[PATCH] drm/self_refresh: Don't trigger the entry timer for self refresh work if CRTC state is inactive

[Liu Ying]

If the CRTC state is already inactive, it doesn't make sense to trigger
the entry timer for self refresh work to make the display enter self
refresh mode, because the disabled CRTC hints that either the entire
display pipeline is disabled or the previous atomic commit is triggered
by the self refresh work(the CRTC is disabled, while the relevant encoder
and bridges could be disabled or not depending on the drivers).

Cc: Rob Clark <robdclark at chromium.org>
Cc: Sean Paul <seanpaul at chromium.org>
Cc: Zain Wang <wzz at rock-chips.com>
Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
Cc: Maxime Ripard <mripard at kernel.org>
Cc: Thomas Zimmermann <tzimmermann at suse.de>
Cc: David Airlie <airlied at linux.ie>
Cc: Daniel Vetter <daniel at ffwll.ch>
Signed-off-by: Liu Ying <victor.liu at nxp.com>
---
 drivers/gpu/drm/drm_self_refresh_helper.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/drm_self_refresh_helper.c b/drivers/gpu/drm/drm_self_refresh_helper.c
index dd33fec5aabd..e76eb3cd22c7 100644
--- a/drivers/gpu/drm/drm_self_refresh_helper.c
+++ b/drivers/gpu/drm/drm_self_refresh_helper.c
@@ -204,8 +204,12 @@ void drm_self_refresh_helper_alter_state(struct drm_atomic_state *state)
 		struct drm_self_refresh_data *sr_data;
 		unsigned int delay;
 
-		/* Don't trigger the entry timer when we're already in SR */
-		if (crtc_state->self_refresh_active)
+		/*
+		 * Don't trigger the entry timer when we're already inactive.
+		 * Note that the inactive state hints that either we're already
+		 * in SR or the entire display pipeline is already disabled.
+		 */
+		if (!crtc_state->active)
 			continue;
 
 		sr_data = crtc->self_refresh_data;
-- 
2.25.1