2021-04-24 06:47:41

by Mauro Carvalho Chehab

Subject: [PATCH 06/78] media: renesas-ceu: fix pm_runtime_get_sync() usage count

The pm_runtime_get_sync() internally increments the
dev->power.usage_count without decrementing it, even on errors.
replace it by the new pm_runtime_resume_and_get(), introduced by:
commit dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
in order to properly decrement the usage counter and avoid memory
leaks.

While here, check if the PM runtime was caught at open time.

Signed-off-by: Mauro Carvalho Chehab <[email protected]>
---
drivers/media/platform/renesas-ceu.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/media/platform/renesas-ceu.c b/drivers/media/platform/renesas-ceu.c
index cd137101d41e..965a7259e707 100644
--- a/drivers/media/platform/renesas-ceu.c
+++ b/drivers/media/platform/renesas-ceu.c
@@ -1099,7 +1099,10 @@ static int ceu_open(struct file *file)

mutex_lock(&ceudev->mlock);
/* Causes soft-reset and sensor power on on first open */
- pm_runtime_get_sync(ceudev->dev);
+ ret = pm_runtime_resume_and_get(ceudev->dev);
+ if (ret < 0)
+ return ret;
+
mutex_unlock(&ceudev->mlock);

return 0;
--
2.30.2

2021-04-24 08:12:37

by jacopo mondi

Subject: Re: [PATCH 06/78] media: renesas-ceu: fix pm_runtime_get_sync() usage count

Hi Mauro,

On Sat, Apr 24, 2021 at 08:44:16AM +0200, Mauro Carvalho Chehab wrote:
> The pm_runtime_get_sync() internally increments the
> dev->power.usage_count without decrementing it, even on errors.
> replace it by the new pm_runtime_resume_and_get(), introduced by:

Nit: 'Replace' as it follows a full stop ?

> commit dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter")
> in order to properly decrement the usage counter and avoid memory
> leaks.
>
> While here, check if the PM runtime was caught at open time.

Nit: Maybe "PM runtime error ..." or something similar as I'm missing the
subject of the phrase.

>
> Signed-off-by: Mauro Carvalho Chehab <[email protected]>
> ---
> drivers/media/platform/renesas-ceu.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/media/platform/renesas-ceu.c b/drivers/media/platform/renesas-ceu.c
> index cd137101d41e..965a7259e707 100644
> --- a/drivers/media/platform/renesas-ceu.c
> +++ b/drivers/media/platform/renesas-ceu.c
> @@ -1099,7 +1099,10 @@ static int ceu_open(struct file *file)
>
> mutex_lock(&ceudev->mlock);
> /* Causes soft-reset and sensor power on on first open */
> - pm_runtime_get_sync(ceudev->dev);
> + ret = pm_runtime_resume_and_get(ceudev->dev);
> + if (ret < 0)
> + return ret;

The mutex should be released before returning

> +
> mutex_unlock(&ceudev->mlock);
>
> return 0;
> --
> 2.30.2
>