From c6eb52b326e7ca98f133f6d6045c683494489a9a Mon Sep 17 00:00:00 2001
From: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Date: Tue, 1 Sep 2020 07:39:52 +0800
Subject: drm/mediatek: Use CPU when fail to get cmdq event
Git-commit: f85acdad07fe36b91f2244263a890bf372528326
Patch-mainline: v5.9-rc6
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322

Even though cmdq client is created successfully, without the cmdq event,
cmdq could not work correctly, so use CPU when fail to get cmdq event.

Fixes: 60fa8c13ab1a ("drm/mediatek: Move gce event property to mutex device node")
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
index 040834bdee9e..c913968ec294 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
@@ -830,13 +830,19 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
 			drm_crtc_index(&mtk_crtc->base));
 		mtk_crtc->cmdq_client = NULL;
 	}
-	ret = of_property_read_u32_index(priv->mutex_node,
-					 "mediatek,gce-events",
-					 drm_crtc_index(&mtk_crtc->base),
-					 &mtk_crtc->cmdq_event);
-	if (ret)
-		dev_dbg(dev, "mtk_crtc %d failed to get mediatek,gce-events property\n",
-			drm_crtc_index(&mtk_crtc->base));
+
+	if (mtk_crtc->cmdq_client) {
+		ret = of_property_read_u32_index(priv->mutex_node,
+						 "mediatek,gce-events",
+						 drm_crtc_index(&mtk_crtc->base),
+						 &mtk_crtc->cmdq_event);
+		if (ret) {
+			dev_dbg(dev, "mtk_crtc %d failed to get mediatek,gce-events property\n",
+				drm_crtc_index(&mtk_crtc->base));
+			cmdq_mbox_destroy(mtk_crtc->cmdq_client);
+			mtk_crtc->cmdq_client = NULL;
+		}
+	}
 #endif
 	return 0;
 }
-- 
2.29.2