diff mbox series

iio: adc: mediatek: fix unset field

Message ID 20201012194618.2170970-1-fparent@baylibre.com (mailing list archive)
State New, archived
Headers show
Series iio: adc: mediatek: fix unset field | expand

Commit Message

Fabien Parent Oct. 12, 2020, 7:46 p.m. UTC
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@baylibre.com>
---
 drivers/iio/adc/mt6577_auxadc.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

Matthias Brugger Oct. 13, 2020, 3:37 p.m. UTC | #1
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@baylibre.com>

Ouch.

Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>

> ---
>   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);
> +
>   	mutex_init(&adc_dev->lock);
>   
>   	mt6577_auxadc_mod_reg(adc_dev->reg_base + MT6577_AUXADC_MISC,
>
Jonathan Cameron Oct. 18, 2020, 10:07 a.m. UTC | #2
On Tue, 13 Oct 2020 17:37:12 +0200
Matthias Brugger <matthias.bgg@gmail.com> 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@baylibre.com>  
> 
> Ouch.
> 
> Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
> 
> > ---
> >   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.

Thanks,

Jonathan

> >   	mutex_init(&adc_dev->lock);
> >   
> >   	mt6577_auxadc_mod_reg(adc_dev->reg_base + MT6577_AUXADC_MISC,
> >
Fabien Parent Oct. 18, 2020, 5:16 p.m. UTC | #3
Hi Jonathan,

On Sun, Oct 18, 2020 at 12:07 PM Jonathan Cameron <jic23@kernel.org> wrote:
>
> On Tue, 13 Oct 2020 17:37:12 +0200
> Matthias Brugger <matthias.bgg@gmail.com> 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@baylibre.com>
> >
> > Ouch.
> >
> > Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
> >
> > > ---
> > >   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,
> > >
>
diff mbox series

Patch

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