Re: [PATCH v4 3/6] iommu/mediatek: Add error path for loop of mm_dts_parse

The mtk_iommu_mm_dts_parse will parse the smi larbs nodes. if the i+1
larb is parsed fail, we should put_device for the 0..i larbs.

There are two places need to comment:
1) The larbid may be not linear mapping, we should loop whole
    the array in the error path.
2) I move this line position: "data->larb_imu[id].dev = &plarbdev->dev;"
    That means set data->larb_imu[id].dev before the error path.
    then we don't need "platform_device_put(plarbdev)" again while
    probe_defer case. All depend on "put_device" in the error path in error
    cases.

Fixes: d2e9a1102cfc ("iommu/mediatek: Contain MM IOMMU flow with the MM TYPE")
Signed-off-by: Yong Wu <yong.wu@mediatek.com>
---
  drivers/iommu/mtk_iommu.c | 42 ++++++++++++++++++++++++++++-----------
  1 file changed, 30 insertions(+), 12 deletions(-)

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 9c5902207bef..f63d4210043d 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c

@@ -1053,8 +1053,10 @@ static int mtk_iommu_mm_dts_parse(struct device *dev, struct component_match **m
  		u32 id;
  
  		larbnode = of_parse_phandle(dev->of_node, "mediatek,larbs", i);
-		if (!larbnode)
-			return -EINVAL;
+		if (!larbnode) {
+			ret = -EINVAL;
+			goto err_larbdev_put;
+		}
  
  		if (!of_device_is_available(larbnode)) {
  			of_node_put(larbnode);

@@ -1067,14 +1069,16 @@ static int mtk_iommu_mm_dts_parse(struct device *dev, struct component_match **m
  
  		plarbdev = of_find_device_by_node(larbnode);
  		of_node_put(larbnode);
-		if (!plarbdev)
-			return -ENODEV;
+		if (!plarbdev) {
+			ret = -ENODEV;
+			goto err_larbdev_put;
+		}
+		data->larb_imu[id].dev = &plarbdev->dev;
  
  		if (!plarbdev->dev.driver) {
-			platform_device_put(plarbdev);
-			return -EPROBE_DEFER;
+			ret = -EPROBE_DEFER;
+			goto err_larbdev_put;
  		}
-		data->larb_imu[id].dev = &plarbdev->dev;
  
  		component_match_add(dev, match, component_compare_dev, &plarbdev->dev);
  		platform_device_put(plarbdev);

@@ -1082,8 +1086,10 @@ static int mtk_iommu_mm_dts_parse(struct device *dev, struct component_match **m
  
  	/* Get smi-(sub)-common dev from the last larb. */
  	smi_subcomm_node = of_parse_phandle(larbnode, "mediatek,smi", 0);
-	if (!smi_subcomm_node)
-		return -EINVAL;
+	if (!smi_subcomm_node) {
+		ret = -EINVAL;
+		goto err_larbdev_put;
+	}
  
  	/*
  	 * It may have two level smi-common. the node is smi-sub-common if it

@@ -1097,8 +1103,10 @@ static int mtk_iommu_mm_dts_parse(struct device *dev, struct component_match **m
  
  	pcommdev = of_find_device_by_node(smicomm_node);
  	of_node_put(smicomm_node);
-	if (!pcommdev)
-		return -EINVAL;
+	if (!pcommdev) {
+		ret = -EINVAL;
+		goto err_larbdev_put;
+	}
  	data->smicomm_dev = &pcommdev->dev;
  
  	link = device_link_add(data->smicomm_dev, dev,

@@ -1106,9 +1114,19 @@ static int mtk_iommu_mm_dts_parse(struct device *dev, struct component_match **m
  	platform_device_put(pcommdev);
  	if (!link) {
  		dev_err(dev, "Unable to link %s.\n", dev_name(data->smicomm_dev));
-		return -EINVAL;
+		ret = -EINVAL;
+		goto err_larbdev_put;
  	}
  	return 0;
+
+err_larbdev_put:
+	/* id may be not linear mapping, loop whole the array */
+	for (i = 0; i < MTK_LARB_NR_MAX; i++) {