From 3b712e43e3876b42b38321ecf790a1f5fe59c834 Mon Sep 17 00:00:00 2001
From: Sean Paul <seanpaul@chromium.org>
Date: Wed, 3 Oct 2018 16:22:31 -0400
Subject: [PATCH] drm/msm: Grab a vblank reference when waiting for commit_done
Git-commit: 3b712e43e3876b42b38321ecf790a1f5fe59c834
Patch-mainline: v4.20-rc6
References: bsc#1051510

Similar to the atomic helpers, we should enable vblank while we're
waiting for the commit to finish. DPU needs this, MDP5 seems to work
fine without it.

Reviewed-by: Abhinav Kumar <abhinavk@codeaurora.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/msm/msm_atomic.c |    5 +++++
 1 file changed, 5 insertions(+)

--- a/drivers/gpu/drm/msm/msm_atomic.c
+++ b/drivers/gpu/drm/msm/msm_atomic.c
@@ -93,7 +93,12 @@ static void msm_atomic_wait_for_commit_d
 		if (!crtc->state->enable)
 			continue;
 
+		if (drm_crtc_vblank_get(crtc))
+			continue;
+
 		kms->funcs->wait_for_crtc_commit_done(kms, crtc);
+
+		drm_crtc_vblank_put(crtc);
 	}
 }