Re: [PATCH] media: sti: Fix reference count leaks

From: Hans Verkuil
Date: Thu Sep 17 2020 - 07:44:00 EST


Hi Jean-Christophe,

I'll take this patch, but while reviewing it I noticed something else:

On 14/06/2020 05:31, wu000273@xxxxxxx wrote:
> From: Qiushi Wu <wu000273@xxxxxxx>
>
> pm_runtime_get_sync() increments the runtime PM usage counter even
> when it returns an error code, causing incorrect ref count if
> pm_runtime_put_noidle() is not called in error handling paths.
> Thus call pm_runtime_put_noidle() if pm_runtime_get_sync() fails.
>
> Signed-off-by: Qiushi Wu <wu000273@xxxxxxx>
> ---
> drivers/media/platform/sti/hva/hva-hw.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/media/platform/sti/hva/hva-hw.c b/drivers/media/platform/sti/hva/hva-hw.c
> index 401aaafa1710..bb13348be083 100644
> --- a/drivers/media/platform/sti/hva/hva-hw.c
> +++ b/drivers/media/platform/sti/hva/hva-hw.c
> @@ -272,6 +272,7 @@ static unsigned long int hva_hw_get_ip_version(struct hva_dev *hva)
>
> if (pm_runtime_get_sync(dev) < 0) {
> dev_err(dev, "%s failed to get pm_runtime\n", HVA_PREFIX);
> + pm_runtime_put_noidle(dev);
> mutex_unlock(&hva->protect_mutex);

This appears to be a spurious mutex_unlock() since I don't see a corresponding mutex_lock.

Jean-Christophe, can you check this and, if I am right, post a patch fixing this?

Regards,

Hans

> return -EFAULT;
> }
> @@ -553,6 +554,7 @@ void hva_hw_dump_regs(struct hva_dev *hva, struct seq_file *s)
>
> if (pm_runtime_get_sync(dev) < 0) {
> seq_puts(s, "Cannot wake up IP\n");
> + pm_runtime_put_noidle(dev);
> mutex_unlock(&hva->protect_mutex);
> return;
> }
>