Re: [PATCH] iio: adc: mediatek: fix unset field

[Fabien Parent]

Hi Jonathan,

On Sun, Oct 18, 2020 at 12:07 PM Jonathan Cameron <jic23@xxxxxxxxxx> wrote:
>
> On Tue, 13 Oct 2020 17:37:12 +0200
> Matthias Brugger <matthias.bgg@xxxxxxxxx> wrote:
>
> > On 12/10/2020 21:46, Fabien Parent wrote:
> > > dev_comp field is used in a couple of places but it is never set. This
> > > results in kernel oops when dereferencing a NULL pointer. Set the
> > > `dev_comp` field correctly in the probe function.
> > >
> > > Fixes: 6d97024dce23 ("iio: adc: mediatek: mt6577-auxadc, add mt6765 support")
> > >
> > > Signed-off-by: Fabien Parent <fparent@xxxxxxxxxxxx>
> >
> > Ouch.
> >
> > Reviewed-by: Matthias Brugger <matthias.bgg@xxxxxxxxx>
> >
> > > ---
> > >   drivers/iio/adc/mt6577_auxadc.c | 2 ++
> > >   1 file changed, 2 insertions(+)
> > >
> > > diff --git a/drivers/iio/adc/mt6577_auxadc.c b/drivers/iio/adc/mt6577_auxadc.c
> > > index ac415cb089cd..7bd48377cd79 100644
> > > --- a/drivers/iio/adc/mt6577_auxadc.c
> > > +++ b/drivers/iio/adc/mt6577_auxadc.c
> > > @@ -276,6 +276,8 @@ static int mt6577_auxadc_probe(struct platform_device *pdev)
> > >             goto err_disable_clk;
> > >     }
> > >
> > > +   adc_dev->dev_comp = of_device_get_match_data(&pdev->dev);
> > > +
>
> Could we switch this to device_get_match_data(&pdev->dev)?
>
> Whilst is unlikely this driver will used in a platform using ACPI, there
> is nothing inside the driver itself preventing this (which is good as no
> reason to do so!)   My main motivation for this is to reduce the chances
> of cut and paste of the of_* functions in future driver.
>
> Also switch the headers to linux/property.h and linux/mod_devicetable.h
> to more tightly reflect what we are using in the driver.

I applied these changes in v2.

>
> Thanks,
>
> Jonathan
>
> > >     mutex_init(&adc_dev->lock);
> > >
> > >     mt6577_auxadc_mod_reg(adc_dev->reg_base + MT6577_AUXADC_MISC,
> > >
>