Re: [PATCH v2] media: st-delta: Fix PM disable depth imbalance in delta_probe

Hans Verkuil
2022-03-07T07:35:39Z

Hi Miaoqian Lin,

On 3/1/22 04:12, Miaoqian Lin wrote:
> The pm_runtime_enable will increase power disable depth.
> If the probe fails, we should use pm_runtime_disable() to balance
> pm_runtime_enable().
>
> Fixes: f386509 ("[media] st-delta: STiH4xx multi-format video decoder v4l2 driver")
> Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
> ---
> changes in v2:
> - remove unused label.
> ---
> drivers/media/platform/sti/delta/delta-v4l2.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/media/platform/sti/delta/delta-v4l2.c b/drivers/media/platform/sti/delta/delta-v4l2.c
> index c887a31ebb54..36ce0775f3f9 100644
> --- a/drivers/media/platform/sti/delta/delta-v4l2.c
> +++ b/drivers/media/platform/sti/delta/delta-v4l2.c
> @@ -1899,6 +1899,7 @@ static int delta_probe(struct platform_device *pdev)
> err_v4l2:
> v4l2_device_unregister(&delta->v4l2_dev);
> err:
> + pm_runtime_disable(dev);

This isn't right. If the devm_kzalloc at the beginning fails, then it also jump
to this label, but at that time no pm_runtime_enable() has been called yet,
so this patch will just introduce another imbalance.

You *do* need a new label here (like you did in v1 of this patch), and update
the 'goto err;' instances after the call to pm_runtime_enable() to go to that
new label.

Regards,

Hans

> return ret;
> }
>