Re: [PATCH] iio: adc: max9611: Fix temperature reading in probe

[Jonathan Cameron]

On Tue, 6 Aug 2019 09:31:14 +0200
Jacopo Mondi <jacopo@xxxxxxxxxx> wrote:

> Hi Jonathan,
> 
> On Mon, Aug 05, 2019 at 06:12:44PM +0100, Jonathan Cameron wrote:
> > On Mon,  5 Aug 2019 17:55:15 +0200
> > Jacopo Mondi <jacopo+renesas@xxxxxxxxxx> wrote:
> >  
> > > The max9611 driver reads the die temperature at probe time to validate
> > > the communication channel. Use the actual read value to perform the test
> > > instead of the read function return value, which was mistakenly used so
> > > far.
> > >
> > > The temperature reading test was only successful because the 0 return
> > > value is in the range of supported temperatures.
> > >
> > > Fixes: 69780a3bbc0b ("iio: adc: Add Maxim max9611 ADC driver")
> > > Signed-off-by: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx>  
> >
> > Applied to the fixes-togreg branch of iio.git and marked for
> > stable.  That'll be a bit fiddly given other changes around this
> > so we may need to do backports.
> >  
> 
> Indeed, I should have mentioned this patch depends on Joe's
> ae8cc91a7d85 ("iio: adc: max9611: Fix misuse of GENMASK macro")
> which is now in linux-next, otherwise it might atually trigger errors
> due to the wrong mask value.
> 
> I wonder if there's a way to keep track of these dependencies for the
> sake of backporting, or it's an operation that has to be carried out
> manually...
A note in the commit message is normally enough as all the stable
maintainers check that first.  In this particular case both patches
are marked for stable so will get picked up automatically in the right
order (hopefully!).

Thanks,

Jonathan

> 
> Thanks
>    j
> 
> >  
> > > ---
> > >  drivers/iio/adc/max9611.c | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/iio/adc/max9611.c b/drivers/iio/adc/max9611.c
> > > index 917223d5ff5b..e9f6b1da1b94 100644
> > > --- a/drivers/iio/adc/max9611.c
> > > +++ b/drivers/iio/adc/max9611.c
> > > @@ -480,7 +480,7 @@ static int max9611_init(struct max9611_dev *max9611)
> > >  	if (ret)
> > >  		return ret;
> > >
> > > -	regval = ret & MAX9611_TEMP_MASK;
> > > +	regval &= MAX9611_TEMP_MASK;
> > >
> > >  	if ((regval > MAX9611_TEMP_MAX_POS &&
> > >  	     regval < MAX9611_TEMP_MIN_NEG) ||
> > > --
> > > 2.22.0
> > >  
> >