[PATCH -next] i2c: imx: Fix PM reference leak in i2c_imx_reg_slave()

[PATCH -next] i2c: imx: Fix PM reference leak in i2c_imx_reg_slave()

[Ye Weihua]

The PM reference count is not expected to be incremented on return in
these functions.

However, pm_runtime_get_sync() will increment the PM reference count
even on failure. forgetting to put the reference again will result in
a leak.

Replace it with pm_runtime_resume_and_get() to keep the usage counter
balanced.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Ye Weihua <yeweihua4@huawei.com>
---
 drivers/i2c/busses/i2c-imx.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index b80fdc1f0092..dc5ca71906db 100644
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -801,7 +801,7 @@ static int i2c_imx_reg_slave(struct i2c_client *client)
 	i2c_imx->last_slave_event = I2C_SLAVE_STOP;
 
 	/* Resume */
-	ret = pm_runtime_get_sync(i2c_imx->adapter.dev.parent);
+	ret = pm_runtime_resume_and_get(i2c_imx->adapter.dev.parent);
 	if (ret < 0) {
 		dev_err(&i2c_imx->adapter.dev, "failed to resume i2c controller");
 		return ret;
@@ -1253,7 +1253,7 @@ static int i2c_imx_xfer(struct i2c_adapter *adapter,
 	struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(adapter);
 	int result;
 
-	result = pm_runtime_get_sync(i2c_imx->adapter.dev.parent);
+	result = pm_runtime_resume_and_get(i2c_imx->adapter.dev.parent);
 	if (result < 0)
 		return result;
 
@@ -1496,7 +1496,7 @@ static int i2c_imx_remove(struct platform_device *pdev)
 	struct imx_i2c_struct *i2c_imx = platform_get_drvdata(pdev);
 	int irq, ret;
 
-	ret = pm_runtime_get_sync(&pdev->dev);
+	ret = pm_runtime_resume_and_get(&pdev->dev);
 	if (ret < 0)
 		return ret;
 
-- 
2.17.1

Re: [PATCH -next] i2c: imx: Fix PM reference leak in i2c_imx_reg_slave()

[Wolfram Sang]

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On Thu, Apr 08, 2021 at 07:06:38PM +0800, Ye Weihua wrote:
> The PM reference count is not expected to be incremented on return in
> these functions.
> 
> However, pm_runtime_get_sync() will increment the PM reference count
> even on failure. forgetting to put the reference again will result in
> a leak.
> 
> Replace it with pm_runtime_resume_and_get() to keep the usage counter
> balanced.
> 
> Reported-by: Hulk Robot <hulkci@huawei.com>
> Signed-off-by: Ye Weihua <yeweihua4@huawei.com>

After rebasing, only one hunk was left:

> @@ -801,7 +801,7 @@ static int i2c_imx_reg_slave(struct i2c_client *client)
>  	i2c_imx->last_slave_event = I2C_SLAVE_STOP;
>  
>  	/* Resume */
> -	ret = pm_runtime_get_sync(i2c_imx->adapter.dev.parent);
> +	ret = pm_runtime_resume_and_get(i2c_imx->adapter.dev.parent);
>  	if (ret < 0) {
>  		dev_err(&i2c_imx->adapter.dev, "failed to resume i2c controller");
>  		return ret;

I applied this to for-next, thanks!


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