Do not reset Merge while using CMDQ because it doesn't wait for
frame done event as CMDQ does and could lead to underrun when
the layer is switching off.

Fixes: aaf94f7c3ae6 ("drm/mediatek: Add display merge async reset control")

Signed-off-by: Hsiao Chien Sung <shawn.sung@mediatek.com>
---
 drivers/gpu/drm/mediatek/mtk_disp_merge.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_disp_merge.c b/drivers/gpu/drm/mediatek/mtk_disp_merge.c
index e525a6b9e5b0..22f768d923d5 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_merge.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_merge.c
@@ -103,7 +103,7 @@ void mtk_merge_stop_cmdq(struct device *dev, struct cmdq_pkt *cmdq_pkt)
 	mtk_ddp_write(cmdq_pkt, 0, &priv->cmdq_reg, priv->regs,
 		      DISP_REG_MERGE_CTRL);
 
-	if (priv->async_clk)
+	if (!cmdq_pkt && priv->async_clk)
 		reset_control_reset(priv->reset_ctl);
 }
 
-- 
2.18.0