From 7f53b19cdff78f696b61cd5987dfe1a5d432676b Mon Sep 17 00:00:00 2001 From: Laurent Pinchart Date: Sat, 4 Mar 2017 15:14:47 +0200 Subject: [PATCH] drm: rcar-du: Arm the page flip event after queuing the page flip The page flip event is armed in the atomic begin handler, creating a race condition with the frame end interrupt that could send the event before the atomic operation actually completes. To avoid that, arm the event in the atomic flush handler after queuing the page flip. This change doesn't fully close the race window, as the frame end interrupt could be generated before the page flip is committed to hardware but only handled after the event is armed. However, the race window is now much smaller. Signed-off-by: Laurent Pinchart Reviewed-by: Kieran Bingham Signed-off-by: Kieran Bingham --- drivers/gpu/drm/rcar-du/rcar_du_crtc.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c index 4ed6f2340af0..5f0664bcd12d 100644 --- a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c +++ b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c @@ -581,17 +581,6 @@ static void rcar_du_crtc_atomic_begin(struct drm_crtc *crtc, struct drm_crtc_state *old_crtc_state) { struct rcar_du_crtc *rcrtc = to_rcar_crtc(crtc); - struct drm_device *dev = rcrtc->crtc.dev; - unsigned long flags; - - if (crtc->state->event) { - WARN_ON(drm_crtc_vblank_get(crtc) != 0); - - spin_lock_irqsave(&dev->event_lock, flags); - rcrtc->event = crtc->state->event; - crtc->state->event = NULL; - spin_unlock_irqrestore(&dev->event_lock, flags); - } if (rcar_du_has(rcrtc->group->dev, RCAR_DU_FEATURE_VSP1_SOURCE)) rcar_du_vsp_atomic_begin(rcrtc); @@ -601,9 +590,20 @@ static void rcar_du_crtc_atomic_flush(struct drm_crtc *crtc, struct drm_crtc_state *old_crtc_state) { struct rcar_du_crtc *rcrtc = to_rcar_crtc(crtc); + struct drm_device *dev = rcrtc->crtc.dev; + unsigned long flags; rcar_du_crtc_update_planes(rcrtc); + if (crtc->state->event) { + WARN_ON(drm_crtc_vblank_get(crtc) != 0); + + spin_lock_irqsave(&dev->event_lock, flags); + rcrtc->event = crtc->state->event; + crtc->state->event = NULL; + spin_unlock_irqrestore(&dev->event_lock, flags); + } + if (rcar_du_has(rcrtc->group->dev, RCAR_DU_FEATURE_VSP1_SOURCE)) rcar_du_vsp_atomic_flush(rcrtc); } -- 2.20.1