Em Sun, 9 May 2021 12:33:49 +0100
Jonathan Cameron <jic23@xxxxxxxxxx> escreveu:
> From: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
>
> This case illustrates why the new pm_runtime_sync_and_get() is good
> in that it makes clear the correct way to handle errors.
>
> Calling pm_runtime_put() on failure of the _get() in pm_runtime_get_sync()
> will potentially result in powering down an already powered down device
> (as we never successfully powered it up. Unlikely to cause any problems
> in reality.
>
> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
This one seems a little odd on my eyes, although I don't know much about
IIO, as it calls RPM get only at:
zpa2326_init_runtime()
on a balanced way, as the routine starts with RPM get() ends with RPM put().
Then it does a put at zpa2326_suspend() and a get at zpa2326_resume().
Can RPM usage_count be zero at suspend (or are there some other part
of IIO core that increments it?). Because, if after resume, usage_count
would be equal to 1, as I guess RPM core prevent negative values.
Regards,
Mauro
> ---
> drivers/iio/pressure/zpa2326.c | 6 ++----
> 1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/iio/pressure/zpa2326.c b/drivers/iio/pressure/zpa2326.c
> index 89295c90f801..97ac3ba399f7 100644
> --- a/drivers/iio/pressure/zpa2326.c
> +++ b/drivers/iio/pressure/zpa2326.c
> @@ -664,11 +664,9 @@ static int zpa2326_resume(const struct iio_dev *indio_dev)
> {
> int err;
>
> - err = pm_runtime_get_sync(indio_dev->dev.parent);
> - if (err < 0) {
> - pm_runtime_put(indio_dev->dev.parent);
> + err = pm_runtime_resume_and_get(indio_dev->dev.parent);
> + if (err < 0)
> return err;
> - }
>
> if (err > 0) {
> /*
Thanks,
Mauro
