Re: [PATCH 4/4] iio: accel: mma8452: use devm_pm_runtime_enable() to fix probe error path

[Jonathan Cameron]

On Fri, 29 May 2026 15:45:44 +0500
Stepan Ionichev <sozdayvek@xxxxxxxxx> wrote:

> mma8452_probe() calls pm_runtime_enable() and then iio_device_register().
> If iio_device_register() fails the function jumps to buffer_cleanup but
> the existing manual unwind does not call pm_runtime_disable(), leaking the
> runtime PM enable_count on probe failure and on subsequent rebind.
> 
> Switch to devm_pm_runtime_enable() so the enable (and the matching
> dont_use_autosuspend) are torn down automatically.  On its new error path
> the probe jumps to the existing buffer_cleanup label so the triggered
> buffer, trigger and regulator cleanup chain stays intact.  The
> pm_runtime_disable() and pm_runtime_set_suspended() calls in
> mma8452_remove() are dropped; the devm action runs after .remove() and
> handles the teardown.
> 
> Signed-off-by: Stepan Ionichev <sozdayvek@xxxxxxxxx>
Same again on not mixing devm with goto.

Side effect here is that the tear down order is completely different from
reverse of setup.

> ---
>  drivers/iio/accel/mma8452.c | 7 +++----
>  1 file changed, 3 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/iio/accel/mma8452.c b/drivers/iio/accel/mma8452.c
> index 15172ba2972c..88ed47d33e03 100644
> --- a/drivers/iio/accel/mma8452.c
> +++ b/drivers/iio/accel/mma8452.c
> @@ -1693,7 +1693,9 @@ static int mma8452_probe(struct i2c_client *client)
>  	if (ret < 0)
>  		goto buffer_cleanup;
>  
> -	pm_runtime_enable(&client->dev);
> +	ret = devm_pm_runtime_enable(&client->dev);
> +	if (ret)
> +		goto buffer_cleanup;
>  	pm_runtime_set_autosuspend_delay(&client->dev,
>  					 MMA8452_AUTO_SUSPEND_DELAY_MS);
>  	pm_runtime_use_autosuspend(&client->dev);
> @@ -1733,9 +1735,6 @@ static void mma8452_remove(struct i2c_client *client)
>  
>  	iio_device_unregister(indio_dev);
>  
> -	pm_runtime_disable(&client->dev);
> -	pm_runtime_set_suspended(&client->dev);
> -
>  	iio_triggered_buffer_cleanup(indio_dev);
>  	mma8452_trigger_cleanup(indio_dev);
>  	mma8452_standby(iio_priv(indio_dev));