[PATCH AUTOSEL 4.14 6/8] drm/imx: notify drm core before sending event during crtc disable

From: Sasha Levin
Date: Wed Jul 10 2019 - 11:03:39 EST

From: Robert Beckett <bob.beckett@xxxxxxxxxxxxx>

[ Upstream commit 78c68e8f5cd24bd32ba4ca1cdfb0c30cf0642685 ]

Notify drm core before sending pending events during crtc disable.
This fixes the first event after disable having an old stale timestamp
by having drm_crtc_vblank_off update the timestamp to now.

This was seen while debugging weston log message:
Warning: computed repaint delay is insane: -8212 msec

This occurred due to:
1. driver starts up
2. fbcon comes along and restores fbdev, enabling vblank
3. vblank_disable_fn fires via timer disabling vblank, keeping vblank
seq number and time set at current value
(some time later)
4. weston starts and does a modeset
5. atomic commit disables crtc while it does the modeset
6. ipu_crtc_atomic_disable sends vblank with old seq number and time

Fixes: a474478642d5 ("drm/imx: fix crtc vblank state regression")

Signed-off-by: Robert Beckett <bob.beckett@xxxxxxxxxxxxx>
Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
Signed-off-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
drivers/gpu/drm/imx/ipuv3-crtc.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/imx/ipuv3-crtc.c b/drivers/gpu/drm/imx/ipuv3-crtc.c
index 957fbf8c55eb..7845202d0486 100644
--- a/drivers/gpu/drm/imx/ipuv3-crtc.c
+++ b/drivers/gpu/drm/imx/ipuv3-crtc.c
@@ -99,14 +99,14 @@ static void ipu_crtc_atomic_disable(struct drm_crtc *crtc,

+ drm_crtc_vblank_off(crtc);
if (crtc->state->event) {
drm_crtc_send_vblank_event(crtc, crtc->state->event);
crtc->state->event = NULL;
- drm_crtc_vblank_off(crtc);

static void imx_drm_crtc_reset(struct drm_crtc *crtc)