Re: [PATCH] iio: adc: at91-sama5d2_adc: fix up casting in at91_adc_read_info_raw()

[Jonathan Cameron <jic23@kernel.org>]

On Tue, 17 Jul 2018 10:12:00 +0200
Ludovic Desroches <ludovic.desroches@microchip.com> wrote:

> On Mon, Jul 09, 2018 at 02:06:59PM +0300, Dan Carpenter wrote:
> > This code is problematic because we're supposed to be writing an int but
> > we instead write to only the high 16 bits.  This doesn't work on big
> > endian systems, and there is a potential that the bottom 16 bits are
> > used without being initialized.
> > 
> > Fixes: 23ec2774f1cc ("iio: adc: at91-sama5d2_adc: add support for position and pressure channels")
> > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> >   
> 
> This patch sounds good and as it has been tested by Eugen:
> Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
> 
> Thanks Dan and Eugen.

Applied to the togreg branch of iio.git and pushed out as testing for the
autobuilders to play with it.

Thanks

Jonathan

> 
> > diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c
> > index e02f7d1c86bc..d5ea84cf6460 100644
> > --- a/drivers/iio/adc/at91-sama5d2_adc.c
> > +++ b/drivers/iio/adc/at91-sama5d2_adc.c
> > @@ -1296,6 +1296,7 @@ static int at91_adc_read_info_raw(struct iio_dev *indio_dev,
> >  {
> >  	struct at91_adc_state *st = iio_priv(indio_dev);
> >  	u32 cor = 0;
> > +	u16 tmp_val;
> >  	int ret;
> >  
> >  	/*
> > @@ -1309,7 +1310,8 @@ static int at91_adc_read_info_raw(struct iio_dev *indio_dev,
> >  		mutex_lock(&st->lock);
> >  
> >  		ret = at91_adc_read_position(st, chan->channel,
> > -					     (u16 *)val);
> > +					     &tmp_val);
> > +		*val = tmp_val;
> >  		mutex_unlock(&st->lock);
> >  		iio_device_release_direct_mode(indio_dev);
> >  
> > @@ -1322,7 +1324,8 @@ static int at91_adc_read_info_raw(struct iio_dev *indio_dev,
> >  		mutex_lock(&st->lock);
> >  
> >  		ret = at91_adc_read_pressure(st, chan->channel,
> > -					     (u16 *)val);
> > +					     &tmp_val);
> > +		*val = tmp_val;
> >  		mutex_unlock(&st->lock);
> >  		iio_device_release_direct_mode(indio_dev);
> >  
> > --
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