Re: [PATCH] staging: iio: ad7192: Use the dedicated reset function

[Jonathan Cameron]

On Thu, 14 Sep 2017 16:31:06 +0200
Michael Hennerich <michael.hennerich@xxxxxxxxxx> wrote:

> On 14.09.2017 15:50, Stefan Popa wrote:
> > SPI host drivers can use DMA to transfer data, so the buffer should be properly allocated.
> > Keeping it on the stack could cause an undefined behavior.
> > 
> > The dedicated reset function solves this issue.
> > 
> > Signed-off-by: Stefan Popa <stefan.popa@xxxxxxxxxx>  
> 
> Acked-by: Michael Hennerich <michael.hennerich@xxxxxxxxxx>

Applied to the togreg branch of iio.git rather than staging
branch as the reset functionality is reasonably recent and
not going to be available in stable kernels etc..

Good work. I was reading this on a plane the other day and
noticed the same issue - always nice when someone else
fixes something on your todo list ;)

Jonathan

> 
> Well done!
> 
> 
> > ---
> >   drivers/staging/iio/adc/ad7192.c | 4 +---
> >   1 file changed, 1 insertion(+), 3 deletions(-)
> > 
> > diff --git a/drivers/staging/iio/adc/ad7192.c b/drivers/staging/iio/adc/ad7192.c
> > index d11c6de..6150d27 100644
> > --- a/drivers/staging/iio/adc/ad7192.c
> > +++ b/drivers/staging/iio/adc/ad7192.c
> > @@ -223,11 +223,9 @@ static int ad7192_setup(struct ad7192_state *st,
> >   	struct iio_dev *indio_dev = spi_get_drvdata(st->sd.spi);
> >   	unsigned long long scale_uv;
> >   	int i, ret, id;
> > -	u8 ones[6];
> >   
> >   	/* reset the serial interface */
> > -	memset(&ones, 0xFF, 6);
> > -	ret = spi_write(st->sd.spi, &ones, 6);
> > +	ret = ad_sd_reset(&st->sd, 48);
> >   	if (ret < 0)
> >   		goto out;
> >   	usleep_range(500, 1000); /* Wait for at least 500us */
> >   
> 
>