[PATCH 4.9 074/175] soc: ti: Fix reference imbalance in knav_dma_probe

Greg Kroah-Hartman
2020-12-28T16:35:54Z

From: Zhang Qilong <zhangqilong3@huawei.com>

[ Upstream commit b4fa73358c306d747a2200aec6f7acb97e5750e6 ]

The patch fix two reference leak.

1) pm_runtime_get_sync will increment pm usage counter even it
failed. Forgetting to call put operation will result in
reference leak.

2) The pm_runtime_enable will increase power disable depth. Thus
a pairing decrement is needed on the error handling path to
keep it balanced.

We fix it by: 1) adding call pm_runtime_put_noidle or
pm_runtime_put_sync in error handling. 2) adding pm_runtime_disable
in error handling, to keep usage counter and disable depth balanced.

Fixes: 88139ed030583 ("soc: ti: add Keystone Navigator DMA support")
Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/soc/ti/knav_dma.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/soc/ti/knav_dma.c b/drivers/soc/ti/knav_dma.c
index 1a7b5caa127b5..b86bea4537325 100644
--- a/drivers/soc/ti/knav_dma.c
+++ b/drivers/soc/ti/knav_dma.c
@@ -752,8 +752,9 @@ static int knav_dma_probe(struct platform_device *pdev)
pm_runtime_enable(kdev->dev);
ret = pm_runtime_get_sync(kdev->dev);
if (ret < 0) {
+ pm_runtime_put_noidle(kdev->dev);
dev_err(kdev->dev, "unable to enable pktdma, err %d\n", ret);
- return ret;
+ goto err_pm_disable;
}

/* Initialise all packet dmas */
@@ -767,13 +768,21 @@ static int knav_dma_probe(struct platform_device *pdev)

if (list_empty(&kdev->list)) {
dev_err(dev, "no valid dma instance\n");
- return -ENODEV;
+ ret = -ENODEV;
+ goto err_put_sync;
}

debugfs_create_file("knav_dma", S_IFREG | S_IRUGO, NULL, NULL,
&knav_dma_debug_ops);

return ret;
+
+err_put_sync:
+ pm_runtime_put_sync(kdev->dev);
+err_pm_disable:
+ pm_runtime_disable(kdev->dev);
+
+ return ret;
}

static int knav_dma_remove(struct platform_device *pdev)
--
2.27.0