[v2 PATCH 3/3] drm/mediatek: Fix cursor plane is not config when primary is updating

[jason-jh.lin]

If cursor plane has updated but primary plane config task is not
finished, mtk_drm_crtc_update_config will call mbox_flush() to clear
all task in current GCE thread and let cursor plane re-send a new
GCE task with cursor + primary plane config to replace the unfinished
GCE task.

So the plane config flag should not be cleared when mailbox callback
with a error status.

Fixes: 9efb16c2fdd6 ("drm/mediatek: Clear pending flag when cmdq packet is done")
Signed-off-by: jason-jh.lin <jason-jh.lin at mediatek.com>
---
 drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
index 274e5c67507d..b96dbc867890 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
@@ -281,6 +281,9 @@ static void ddp_cmdq_cb(struct mbox_client *cl, void *mssg)
 	struct mtk_crtc_state *state;
 	unsigned int i;
 
+	if (data->sta < 0)
+		return;
+
 	state = to_mtk_crtc_state(mtk_crtc->base.state);
 
 	state->pending_config = false;
-- 
2.18.0