[PATCH v3 2/4] drm/imx: notify drm core before sending event during crtc disable

Robert Beckett
2019-06-25T18:02:51Z

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 occured 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@collabora.com>
---
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 9cc1d678674f..e04d6efff1b5 100644
--- a/drivers/gpu/drm/imx/ipuv3-crtc.c
+++ b/drivers/gpu/drm/imx/ipuv3-crtc.c
@@ -91,14 +91,14 @@ static void ipu_crtc_atomic_disable(struct drm_crtc *crtc,
ipu_dc_disable(ipu);
ipu_prg_disable(ipu);

+ drm_crtc_vblank_off(crtc);
+
spin_lock_irq(&crtc->dev->event_lock);
if (crtc->state->event) {
drm_crtc_send_vblank_event(crtc, crtc->state->event);
crtc->state->event = NULL;
}
spin_unlock_irq(&crtc->dev->event_lock);
-
- drm_crtc_vblank_off(crtc);
}

static void imx_drm_crtc_reset(struct drm_crtc *crtc)
--
2.18.0