From: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Thu, 5 Apr 2018 17:44:48 +0200
Subject: drm/vc4: Always obey implicit sync
Git-commit: 2227a7a219fdd2b925b1e861f36255efd149ff6d
Patch-mainline: v4.19-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

Same justification as for drm_gem_fb_prepare_fb.

Cc: Eric Anholt <eric@anholt.net>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180405154449.23038-9-daniel.vetter@ffwll.ch
Link: https://patchwork.freedesktop.org/patch/msgid/20180409085134.27321-1-daniel.vetter@ffwll.ch

Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/vc4/vc4_plane.c |   11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

--- a/drivers/gpu/drm/vc4/vc4_plane.c
+++ b/drivers/gpu/drm/vc4/vc4_plane.c
@@ -864,18 +864,21 @@ static int vc4_prepare_fb(struct drm_pla
 	struct dma_fence *fence;
 	int ret;
 
-	if ((plane->state->fb == state->fb) || !state->fb)
+	if (!state->fb)
 		return 0;
 
 	bo = to_vc4_bo(&drm_fb_cma_get_gem_obj(state->fb, 0)->base);
 
+	fence = reservation_object_get_excl_rcu(bo->resv);
+	drm_atomic_set_fence_for_plane(state, fence);
+
+	if (plane->state->fb == state->fb)
+		return 0;
+
 	ret = vc4_bo_inc_usecnt(bo);
 	if (ret)
 		return ret;
 
-	fence = reservation_object_get_excl_rcu(bo->resv);
-	drm_atomic_set_fence_for_plane(state, fence);
-
 	return 0;
 }