From c16b85559dcfb5a348cc085a7b4c75ed49b05e2c Mon Sep 17 00:00:00 2001
From: Helen Koike <helen.koike@collabora.com>
Date: Mon, 3 Jun 2019 13:56:09 -0300
Subject: [PATCH] drm/vc4: fix fb references in async update
Git-commit: c16b85559dcfb5a348cc085a7b4c75ed49b05e2c
Patch-mainline: v5.2-rc4
References: bsc#1141312

[ adjusted the context to match with SLE15-SP1 -- tiwai ]

Async update callbacks are expected to set the old_fb in the new_state
so prepare/cleanup framebuffers are balanced.

Calling drm_atomic_set_fb_for_plane() (which gets a reference of the new
fb and put the old fb) is not required, as it's taken care by
drm_mode_cursor_universal() when calling drm_atomic_helper_update_plane().

Cc: <stable@vger.kernel.org> # v4.19+
Fixes: 539c320bfa97 ("drm/vc4: update cursors asynchronously through atomic")
Suggested-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Helen Koike <helen.koike@collabora.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190603165610.24614-5-helen.koike@collabora.com
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/vc4/vc4_plane.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/gpu/drm/vc4/vc4_plane.c
+++ b/drivers/gpu/drm/vc4/vc4_plane.c
@@ -815,7 +815,7 @@ static void vc4_plane_atomic_async_updat
 
 	if (plane->state->fb != state->fb) {
 		vc4_plane_async_set_fb(plane, state->fb);
-		drm_atomic_set_fb_for_plane(plane->state, state->fb);
+		swap(plane->state->fb, state->fb);
 	}
 
 	/* Set the cursor's position on the screen.  This is the