Re: [PATCH] iio: accel: kxsd9: Fix runtime PM error handling and scoping

[Jonathan Cameron <jic23@kernel.org>]

On Tue, 16 Jun 2026 01:33:30 +0530
Biren Pandya <birenpandya@gmail.com> wrote:

> The kxsd9 driver uses pm_runtime_get_sync() in multiple places without
> checking its return value, which can lead to silent failures. It also
> relies on manual pm_runtime_put_autosuspend() calls in various return
> paths, which is prone to memory leaks if a return path is missed.
> 
> Fix the runtime PM handling by using the new scoped guards and proper
> error checking:
> - In kxsd9_write_raw() and kxsd9_read_raw(), use the scoped
>   PM_RUNTIME_ACQUIRE_IF_ENABLED_AUTOSUSPEND() macro to safely automate
>   cleanup on function return, while maintaining the behavior of
>   waking up a suspended device via pm_runtime_resume_and_get().
>   This allows us to cleanly remove all manual puts and error gotos.

Somewhere here mention that one of the puts was missing.

> - In kxsd9_buffer_preenable(), replace pm_runtime_get_sync() with
>   pm_runtime_resume_and_get() to safely check for errors and handle
>   usage-counter unwinding on failure.
> - In kxsd9_common_remove(), replace pm_runtime_get_sync() with
>   pm_runtime_resume_and_get() and only invoke kxsd9_power_down()
>   if the resume succeeds. This prevents unbalanced regulator disable
>   warnings and bus timeouts if the device is already suspended.
> 
> Signed-off-by: Biren Pandya <birenpandya@gmail.com>

Given this fixes a path, needs a Fixes tag.

Otherwise, what Andy said.

> ---
>  drivers/iio/accel/kxsd9.c | 50 +++++++++++++++++++--------------------
>  1 file changed, 24 insertions(+), 26 deletions(-)
> 
> diff --git a/drivers/iio/accel/kxsd9.c b/drivers/iio/accel/kxsd9.c
> index 4717d80fc24a..f23d1660e6da 100644
> --- a/drivers/iio/accel/kxsd9.c
> +++ b/drivers/iio/accel/kxsd9.c
> @@ -139,68 +139,63 @@ static int kxsd9_write_raw(struct iio_dev *indio_dev,
>  			   int val2,
>  			   long mask)
>  {
> -	int ret = -EINVAL;
>  	struct kxsd9_state *st = iio_priv(indio_dev);
>  
> -	pm_runtime_get_sync(st->dev);
> +	PM_RUNTIME_ACQUIRE_IF_ENABLED_AUTOSUSPEND(st->dev, pm);
> +	if (PM_RUNTIME_ACQUIRE_ERR(&pm))
> +		return PM_RUNTIME_ACQUIRE_ERR(&pm);
>  
>  	if (mask == IIO_CHAN_INFO_SCALE) {
>  		/* Check no integer component */
>  		if (val)
>  			return -EINVAL;

This one is a real fix that needed addressing as it exits
with an error code leaving the power on.

> -		ret = kxsd9_write_scale(indio_dev, val2);
> +		return kxsd9_write_scale(indio_dev, val2);
>  	}
>  
> -	pm_runtime_put_autosuspend(st->dev);
> -
> -	return ret;
> +	return -EINVAL;
>  }