[PATCH 6.0 0811/1073] iommu/mediatek: Add platform_device_put for recovering the device refcnt

Greg Kroah-Hartman
2022-12-28T16:33:11Z

From: Yong Wu <yong.wu@mediatek.com>

[ Upstream commit dcb40e9fcce9bd251eaff19f3724131db522846c ]

Add platform_device_put to match with of_find_device_by_node.

Meanwhile, I add a new variable "pcommdev" which is for smi common device.
Otherwise, "platform_device_put(plarbdev)" for smi-common dev may be not
readable. And add a checking for whether pcommdev is NULL.

Fixes: d2e9a1102cfc ("iommu/mediatek: Contain MM IOMMU flow with the MM TYPE")
Signed-off-by: Yong Wu <yong.wu@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Link: https://lore.kernel.org/r/20221018024258.19073-2-yong.wu@mediatek.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/iommu/mtk_iommu.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 0c1c0d8e4d06..93005e63fc7f 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -1041,7 +1041,7 @@ static int mtk_iommu_mm_dts_parse(struct device *dev, struct component_match **m
struct mtk_iommu_data *data)
{
struct device_node *larbnode, *smicomm_node, *smi_subcomm_node;
- struct platform_device *plarbdev;
+ struct platform_device *plarbdev, *pcommdev;
struct device_link *link;
int i, larb_nr, ret;

@@ -1072,12 +1072,14 @@ static int mtk_iommu_mm_dts_parse(struct device *dev, struct component_match **m
}
if (!plarbdev->dev.driver) {
of_node_put(larbnode);
+ platform_device_put(plarbdev);
return -EPROBE_DEFER;
}
data->larb_imu[id].dev = &plarbdev->dev;

component_match_add_release(dev, match, component_release_of,
component_compare_of, larbnode);
+ platform_device_put(plarbdev);
}

/* Get smi-(sub)-common dev from the last larb. */
@@ -1095,12 +1097,15 @@ static int mtk_iommu_mm_dts_parse(struct device *dev, struct component_match **m
else
smicomm_node = smi_subcomm_node;

- plarbdev = of_find_device_by_node(smicomm_node);
+ pcommdev = of_find_device_by_node(smicomm_node);
of_node_put(smicomm_node);
- data->smicomm_dev = &plarbdev->dev;
+ if (!pcommdev)
+ return -ENODEV;
+ data->smicomm_dev = &pcommdev->dev;

link = device_link_add(data->smicomm_dev, dev,
DL_FLAG_STATELESS | DL_FLAG_PM_RUNTIME);
+ platform_device_put(pcommdev);
if (!link) {
dev_err(dev, "Unable to link %s.\n", dev_name(data->smicomm_dev));
return -EINVAL;
--
2.35.1