Hello Dinghao,
On Wed, 2020-05-20 at 21:29 +0800, Dinghao Liu wrote:
> pm_runtime_get_sync() increments the runtime PM usage counter even
> the call returns an error code. Thus a pairing decrement is needed
> on the error handling path to keep the counter balanced.
I believe, this is the wrong place for such kind of fix.
pm_runtime_get_sync() has obviously a broken semantics with regards to
your observation but no other driver does what you propose.
I think the proper fix belong into PM subsystem, please take a look
onto commit 15bcb91d7e60 "PM / Runtime: Implement autosuspend support".
> Signed-off-by: Dinghao Liu <dinghao.liu@xxxxxxxxxx>
> ---
> drivers/char/hw_random/ks-sa-rng.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/char/hw_random/ks-sa-rng.c b/drivers/char/hw_random/ks-sa-rng.c
> index e2330e757f1f..85c81da4a8af 100644
> --- a/drivers/char/hw_random/ks-sa-rng.c
> +++ b/drivers/char/hw_random/ks-sa-rng.c
> @@ -244,6 +244,7 @@ static int ks_sa_rng_probe(struct platform_device *pdev)
> ret = pm_runtime_get_sync(dev);
> if (ret < 0) {
> dev_err(dev, "Failed to enable SA power-domain\n");
> + pm_runtime_put_sync(dev);
> pm_runtime_disable(dev);
> return ret;
> }
--
Alexander Sverdlin.
