Re: [PATCH] iio: gyro: mpu3050: Fix runtime PM leak in mpu3050_drdy_trigger_set_state()

[Jonathan Cameron]

On Wed, 16 Sep 2026 16:29:49 +0000
Wentao Liang <vulab@xxxxxxxxxxx> wrote:

> The enable path of the trigger state callback called
> pm_runtime_get_sync() and returned early on every following register
> access failure without releasing the runtime PM reference, leaving
> the device powered permanently. Use pm_runtime_resume_and_get() to
> propagate resume errors without bumping the usage count, and release
> the reference on all error paths before returning.
> 
> Fixes: 3904b28efb2c ("iio: gyro: Add driver for the MPU-3050 gyroscope")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Wentao Liang <vulab@xxxxxxxxxxx>

Take another look at the code that results and think about whether having a
unified cleanup block makes sense as it stands.  There are two legs in this
function in if / else and the cleanup block only has anything to do with one
of them.  That is a strong sign that it is time to split the function up
and introduce two helpers (one for each of the if / else). Those helper
functions can then do appropriate error handling.

So fix is valid but larger changes needed to ensure the code remains
maintainable.

Thanks,

Jonathan


> ---
>  drivers/iio/gyro/mpu3050-core.c | 19 +++++++++++++------
>  1 file changed, 13 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/iio/gyro/mpu3050-core.c b/drivers/iio/gyro/mpu3050-core.c
> index d84e04e4b431..aab2984a0c09 100644
> --- a/drivers/iio/gyro/mpu3050-core.c
> +++ b/drivers/iio/gyro/mpu3050-core.c
> @@ -988,20 +988,23 @@ static int mpu3050_drdy_trigger_set_state(struct iio_trigger *trig,
>  		return 0;
>  	} else {
>  		/* Else we're enabling the trigger from this point */
> -		pm_runtime_get_sync(mpu3050->dev);
> +		ret = pm_runtime_resume_and_get(mpu3050->dev);
> +		if (ret)
> +			return ret;
> +
>  		mpu3050->hw_irq_trigger = true;
>  
>  		/* Disable all things in the FIFO */
>  		ret = regmap_write(mpu3050->map, MPU3050_FIFO_EN, 0);
>  		if (ret)
> -			return ret;
> +			goto err_pm_put;
>  
>  		/* Reset and enable the FIFO */
>  		ret = regmap_set_bits(mpu3050->map, MPU3050_USR_CTRL,
>  				      MPU3050_USR_CTRL_FIFO_EN |
>  				      MPU3050_USR_CTRL_FIFO_RST);
>  		if (ret)
> -			return ret;
> +			goto err_pm_put;
>  
>  		mpu3050->pending_fifo_footer = false;
>  
> @@ -1013,12 +1016,12 @@ static int mpu3050_drdy_trigger_set_state(struct iio_trigger *trig,
>  				   MPU3050_FIFO_EN_GYRO_ZOUT |
>  				   MPU3050_FIFO_EN_FOOTER);
>  		if (ret)
> -			return ret;
> +			goto err_pm_put;
>  
>  		/* Configure the sample engine */
>  		ret = mpu3050_start_sampling(mpu3050);
>  		if (ret)
> -			return ret;
> +			goto err_pm_put;
>  
>  		/* Clear IRQ flag */
>  		ret = regmap_read(mpu3050->map, MPU3050_INT_STATUS, &val);
> @@ -1037,10 +1040,14 @@ static int mpu3050_drdy_trigger_set_state(struct iio_trigger *trig,
>  
>  		ret = regmap_write(mpu3050->map, MPU3050_INT_CFG, val);
>  		if (ret)
> -			return ret;
> +			goto err_pm_put;
>  	}
>  
>  	return 0;
> +
> +err_pm_put:
> +	pm_runtime_put_autosuspend(mpu3050->dev);
> +	return ret;
>  }
>  
>  static const struct iio_trigger_ops mpu3050_trigger_ops = {