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SubjectRe: [PATCH] [v2] media: vsp1: Fix runtime PM imbalance on error
Hello Dinghao,

Thank you for the patch.

On Mon, Jun 08, 2020 at 01:29:19PM +0800, Dinghao Liu wrote:
> pm_runtime_get_sync() increments the runtime PM usage counter even
> when it returns an error code. Thus a pairing decrement is needed on
> the error handling path to keep the counter balanced.
>
> Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

I have however received multiple similar patches recently, for different
drivers. I've CC'ed Rafael, the PM maintainer, in one of those e-mail
threads, and questioned whether we should really mass-patch drivers, or
fix the issue in pm_runtime_get_sync(). I'll defer pushing this patch
until that discussion comes to a conclusion.

> ---
>
> Changelog:
>
> v2: - Fix the imbalance in vsp1_device_get().
> Use vsp1_device_get() and vsp1_device_put()
> to replace pm_runtime_get_sync() and
> pm_runtime_put_sync() in vsp1_probe().
> ---
> drivers/media/platform/vsp1/vsp1_drv.c | 11 ++++++++---
> 1 file changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/media/platform/vsp1/vsp1_drv.c b/drivers/media/platform/vsp1/vsp1_drv.c
> index c650e45bb0ad..dc62533cf32c 100644
> --- a/drivers/media/platform/vsp1/vsp1_drv.c
> +++ b/drivers/media/platform/vsp1/vsp1_drv.c
> @@ -562,7 +562,12 @@ int vsp1_device_get(struct vsp1_device *vsp1)
> int ret;
>
> ret = pm_runtime_get_sync(vsp1->dev);
> - return ret < 0 ? ret : 0;
> + if (ret < 0) {
> + pm_runtime_put_noidle(vsp1->dev);
> + return ret;
> + }
> +
> + return 0;
> }
>
> /*
> @@ -845,12 +850,12 @@ static int vsp1_probe(struct platform_device *pdev)
> /* Configure device parameters based on the version register. */
> pm_runtime_enable(&pdev->dev);
>
> - ret = pm_runtime_get_sync(&pdev->dev);
> + ret = vsp1_device_get(vsp1);
> if (ret < 0)
> goto done;
>
> vsp1->version = vsp1_read(vsp1, VI6_IP_VERSION);
> - pm_runtime_put_sync(&pdev->dev);
> + vsp1_device_put(vsp1);
>
> for (i = 0; i < ARRAY_SIZE(vsp1_device_infos); ++i) {
> if ((vsp1->version & VI6_IP_VERSION_MODEL_MASK) ==

--
Regards,

Laurent Pinchart

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