linux-kernel - Re: [PATCH v2 2/2] iio: gyro: mpu3050-core: use pm_runtime_resume_and

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Message-ID: <a75be02da0b55997b2384a481d85b680d1372a78.camel@gmail.com>
Date: Tue, 03 Feb 2026 09:45:34 +0000
From: Nuno Sá <noname.nuno@...il.com>
To: Antoniu Miclaus <antoniu.miclaus@...log.com>, Linus Walleij	
 <linus.walleij@...aro.org>, Jonathan Cameron <jic23@...nel.org>, Lars-Peter
 Clausen <lars@...afoo.de>, linux-iio@...r.kernel.org,
 linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 2/2] iio: gyro: mpu3050-core: use
 pm_runtime_resume_and_get()

On Mon, 2026-02-02 at 16:56 +0200, Antoniu Miclaus wrote:
> Replace pm_runtime_get_sync() with pm_runtime_resume_and_get() in
> mpu3050_read_raw() and mpu3050_buffer_preenable(). Unlike
> pm_runtime_get_sync(), the usage count is not incremented on error.
> 
> In preenable, call pm_runtime_put_autosuspend() if set_8khz_samplerate()
> fails since postdisable won't be called on preenable failure.
> 
> Signed-off-by: Antoniu Miclaus <antoniu.miclaus@...log.com>
> ---

To me this is more than just reference counting. It's also about proper error handling.

- Nuno Sá

>  drivers/iio/gyro/mpu3050-core.c | 17 +++++++++++++----
>  1 file changed, 13 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/iio/gyro/mpu3050-core.c b/drivers/iio/gyro/mpu3050-core.c
> index ee2fcd20545d..1cc421eb4782 100644
> --- a/drivers/iio/gyro/mpu3050-core.c
> +++ b/drivers/iio/gyro/mpu3050-core.c
> @@ -322,7 +322,9 @@ static int mpu3050_read_raw(struct iio_dev *indio_dev,
>  		}
>  	case IIO_CHAN_INFO_RAW:
>  		/* Resume device */
> -		pm_runtime_get_sync(mpu3050->dev);
> +		ret = pm_runtime_resume_and_get(mpu3050->dev);
> +		if (ret)
> +			return ret;
>  		mutex_lock(&mpu3050->lock);
>  
>  		ret = mpu3050_set_8khz_samplerate(mpu3050);
> @@ -647,12 +649,19 @@ static irqreturn_t mpu3050_trigger_handler(int irq, void *p)
>  static int mpu3050_buffer_preenable(struct iio_dev *indio_dev)
>  {
>  	struct mpu3050 *mpu3050 = iio_priv(indio_dev);
> +	int ret;
>  
> -	pm_runtime_get_sync(mpu3050->dev);
> +	ret = pm_runtime_resume_and_get(mpu3050->dev);
> +	if (ret)
> +		return ret;
>  
>  	/* Unless we have OUR trigger active, run at full speed */
> -	if (!mpu3050->hw_irq_trigger)
> -		return mpu3050_set_8khz_samplerate(mpu3050);
> +	if (!mpu3050->hw_irq_trigger) {
> +		ret = mpu3050_set_8khz_samplerate(mpu3050);
> +		if (ret)
> +			pm_runtime_put_autosuspend(mpu3050->dev);