[PATCH v4 2/2] drm/mediatek: add devlink to cmdq dev

["jason-jh.lin" <jason-jh.lin@xxxxxxxxxxxx>]

Add devlink to cmdq to make sure the order of suspend and resume
is correct.

Signed-off-by: jason-jh.lin <jason-jh.lin@xxxxxxxxxxxx>
---
 drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 43 ++++++++++++++++++-------
 1 file changed, 31 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
index 0b4012335e7a..612d1d69c16c 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
@@ -60,6 +60,7 @@ struct mtk_drm_crtc {
 #endif
 
 	struct device			*mmsys_dev;
+	struct device			*drm_dev;
 	struct mtk_mutex		*mutex;
 	unsigned int			ddp_comp_nr;
 	struct mtk_ddp_comp		**ddp_comp;
@@ -159,6 +160,7 @@ static void mtk_drm_crtc_destroy(struct drm_crtc *crtc)
 	mtk_drm_cmdq_pkt_destroy(&mtk_crtc->cmdq_handle);
 
 	if (mtk_crtc->cmdq_client.chan) {
+		device_link_remove(mtk_crtc->drm_dev, mtk_crtc->cmdq_client.chan->mbox->dev);
 		mbox_free_channel(mtk_crtc->cmdq_client.chan);
 		mtk_crtc->cmdq_client.chan = NULL;
 	}
@@ -902,6 +904,7 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
 		return -ENOMEM;
 
 	mtk_crtc->mmsys_dev = priv->mmsys_dev;
+	mtk_crtc->drm_dev = priv->dev;
 	mtk_crtc->ddp_comp_nr = path_len;
 	mtk_crtc->ddp_comp = devm_kmalloc_array(dev, mtk_crtc->ddp_comp_nr,
 						sizeof(*mtk_crtc->ddp_comp),
@@ -969,6 +972,18 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
 	}
 
 	if (mtk_crtc->cmdq_client.chan) {
+		struct device_link *link;
+
+		/* add devlink to cmdq dev to make sure suspend/resume order is correct */
+		link = device_link_add(priv->dev, mtk_crtc->cmdq_client.chan->mbox->dev,
+				       DL_FLAG_PM_RUNTIME | DL_FLAG_STATELESS);
+		if (!link) {
+			dev_err(priv->dev, "Unable to link dev=%s\n",
+				dev_name(mtk_crtc->cmdq_client.chan->mbox->dev));
+			ret = -ENODEV;
+			goto cmdq_err;
+		}
+
 		ret = of_property_read_u32_index(priv->mutex_node,
 						 "mediatek,gce-events",
 						 i,
@@ -976,22 +991,26 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
 		if (ret) {
 			dev_dbg(dev, "mtk_crtc %d failed to get mediatek,gce-events property\n",
 				drm_crtc_index(&mtk_crtc->base));
-			mbox_free_channel(mtk_crtc->cmdq_client.chan);
-			mtk_crtc->cmdq_client.chan = NULL;
-		} else {
-			ret = mtk_drm_cmdq_pkt_create(&mtk_crtc->cmdq_client,
-						      &mtk_crtc->cmdq_handle,
-						      PAGE_SIZE);
-			if (ret) {
-				dev_dbg(dev, "mtk_crtc %d failed to create cmdq packet\n",
-					drm_crtc_index(&mtk_crtc->base));
-				mbox_free_channel(mtk_crtc->cmdq_client.chan);
-				mtk_crtc->cmdq_client.chan = NULL;
-			}
+			goto cmdq_err;
+		}
+
+		ret = mtk_drm_cmdq_pkt_create(&mtk_crtc->cmdq_client,
+					      &mtk_crtc->cmdq_handle,
+					      PAGE_SIZE);
+		if (ret) {
+			dev_dbg(dev, "mtk_crtc %d failed to create cmdq packet\n",
+				drm_crtc_index(&mtk_crtc->base));
+			goto cmdq_err;
 		}
 
 		/* for sending blocking cmd in crtc disable */
 		init_waitqueue_head(&mtk_crtc->cb_blocking_queue);
+
+cmdq_err:
+		if (ret) {
+			mbox_free_channel(mtk_crtc->cmdq_client.chan);
+			mtk_crtc->cmdq_client.chan = NULL;
+		}
 	}
 #endif
 	return 0;
-- 
2.18.0