[PATCH -next] i2c: omap: fix PM reference leak in omap_i2c_probe()

[PATCH -next] i2c: omap: fix PM reference leak in omap_i2c_probe()

[Li Huafei]

pm_runtime_get_sync will increment pm usage counter even it failed.
Forgetting to putting operation will result in reference leak here. Fix
it by replacing it with pm_runtime_resume_and_get to keep usage counter
balanced.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Li Huafei <lihuafei1@huawei.com>
---
 drivers/i2c/busses/i2c-omap.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 12ac4212aded..edbe498d49b8 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -1404,7 +1404,7 @@ omap_i2c_probe(struct platform_device *pdev)
 	pm_runtime_set_autosuspend_delay(omap->dev, OMAP_I2C_PM_TIMEOUT);
 	pm_runtime_use_autosuspend(omap->dev);
 
-	r = pm_runtime_get_sync(omap->dev);
+	r = pm_runtime_resume_and_get(omap->dev);
 	if (r < 0)
 		goto err_free_mem;
 
@@ -1525,7 +1525,7 @@ static int omap_i2c_remove(struct platform_device *pdev)
 	int ret;
 
 	i2c_del_adapter(&omap->adapter);
-	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: omap: fix PM reference leak in omap_i2c_probe()

[Vignesh Raghavendra]

Hi.

On 4/8/21 6:26 PM, Li Huafei wrote:
> pm_runtime_get_sync will increment pm usage counter even it failed.
> Forgetting to putting operation will result in reference leak here. Fix
> it by replacing it with pm_runtime_resume_and_get to keep usage counter
> balanced.
> 
> Reported-by: Hulk Robot <hulkci@huawei.com>
> Signed-off-by: Li Huafei <lihuafei1@huawei.com>
> ---
>  drivers/i2c/busses/i2c-omap.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
> index 12ac4212aded..edbe498d49b8 100644
> --- a/drivers/i2c/busses/i2c-omap.c
> +++ b/drivers/i2c/busses/i2c-omap.c
> @@ -1404,7 +1404,7 @@ omap_i2c_probe(struct platform_device *pdev)
>  	pm_runtime_set_autosuspend_delay(omap->dev, OMAP_I2C_PM_TIMEOUT);
>  	pm_runtime_use_autosuspend(omap->dev);
>  
> -	r = pm_runtime_get_sync(omap->dev);
> +	r = pm_runtime_resume_and_get(omap->dev);
>  	if (r < 0)
>  		goto err_free_mem;
>  
> @@ -1525,7 +1525,7 @@ static int omap_i2c_remove(struct platform_device *pdev)
>  	int ret;
>  
>  	i2c_del_adapter(&omap->adapter);
> -	ret = pm_runtime_get_sync(&pdev->dev);
> +	ret = pm_runtime_resume_and_get(&pdev->dev);
>  	if (ret < 0)
>  		return ret;
>  
> 
There is a similar patch at: lore.kernel.org/r/20210407033030.13419-1-dinghao.liu@zju.edu.cn
But seems like this patch is better as it fixes module remove path as well.
Would appreciate if you could work with author of above patch and come up
with a single patch.

Could you add stable tag and repost given that pm_runtime_resume_and_get()
API is backported to stable kernels such as v5.4?

Regards
Vignesh

Re: [PATCH -next] i2c: omap: fix PM reference leak in omap_i2c_probe()

[Wolfram Sang]

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On Thu, Apr 08, 2021 at 08:56:48PM +0800, Li Huafei wrote:
> pm_runtime_get_sync will increment pm usage counter even it failed.
> Forgetting to putting operation will result in reference leak here. Fix
> it by replacing it with pm_runtime_resume_and_get to keep usage counter
> balanced.
> 
> Reported-by: Hulk Robot <hulkci@huawei.com>
> Signed-off-by: Li Huafei <lihuafei1@huawei.com>

Thanks, yet I applied this series now:

http://patchwork.ozlabs.org/project/linux-i2c/list/?series=217733&state=*


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