From: Boris Brezillon <boris.brezillon@free-electrons.com>
Date: Fri, 16 Jun 2017 10:30:33 +0200
Subject: drm/vc4: Send a VBLANK event when disabling a CRTC
Git-commit: edeb729f7929d1372ab426a7f56fd0b337ba5751
Patch-mainline: v4.14-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

VBLANK events are missed when the CRTC is being disabled because the
driver does not wait till the end of the frame before stopping the
HVS and PV blocks. In this case, we should explicitly issue a VBLANK
event if there's one waiting.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Link: http://patchwork.freedesktop.org/patch/msgid/1497601833-24588-1-git-send-email-boris.brezillon@free-electrons.com

Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/vc4/vc4_crtc.c |   13 +++++++++++++
 1 file changed, 13 insertions(+)

--- a/drivers/gpu/drm/vc4/vc4_crtc.c
+++ b/drivers/gpu/drm/vc4/vc4_crtc.c
@@ -518,6 +518,19 @@ static void vc4_crtc_disable(struct drm_
 	WARN_ON_ONCE((HVS_READ(SCALER_DISPSTATX(chan)) &
 		      (SCALER_DISPSTATX_FULL | SCALER_DISPSTATX_EMPTY)) !=
 		     SCALER_DISPSTATX_EMPTY);
+
+	/*
+	 * Make sure we issue a vblank event after disabling the CRTC if
+	 * someone was waiting it.
+	 */
+	if (crtc->state->event) {
+		unsigned long flags;
+
+		spin_lock_irqsave(&dev->event_lock, flags);
+		drm_crtc_send_vblank_event(crtc, crtc->state->event);
+		crtc->state->event = NULL;
+		spin_unlock_irqrestore(&dev->event_lock, flags);
+	}
 }
 
 static void vc4_crtc_update_dlist(struct drm_crtc *crtc)