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

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Message-ID: <20260207154956.10bd4dff@jic23-huawei>
Date: Sat, 7 Feb 2026 15:49:56 +0000
From: Jonathan Cameron <jic23@...nel.org>
To: Nuno Sá <noname.nuno@...il.com>
Cc: Antoniu Miclaus <antoniu.miclaus@...log.com>, Linus Walleij	
 <linus.walleij@...aro.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 Tue, 03 Feb 2026 09:45:34 +0000
Nuno Sá <noname.nuno@...il.com> wrote:

> 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.
Agreed. I think these should both have fixes tags
and a commit message that calls out a little more clearly what is being fixed.


Jonathan

> 
> - 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);