Re: [PATCH 4/5] iio: light: lm3533-als: remove explicit parent assignment

2020-05-29 Thread Ardelean, Alexandru
On Fri, 2020-05-29 at 12:16 +0200, Johan Hovold wrote:
> [External]
> 
> On Fri, May 22, 2020 at 11:22:07AM +0300, Alexandru Ardelean wrote:
> > This assignment is the more peculiar of the bunch as it assigns the parent
> > of the platform-device's device (i.e. pdev->dev.parent) as the IIO device's
> > parent.
> > 
> > It's unclear whether this is intentional or not.
> > Hence it is in it's own patch.
> 
> Yeah, we have a few mfd drivers whose child drivers registers their
> class devices directly under the parent mfd device rather than the
> corresponding child platform device.
> 
> Since it's done consistently I think you need to update them all if you
> really want to change this. 
> 
> And it may not be worth it since at least in theory someone could now be
> relying on this topology.

Thanks for the feedback.
I guess, it could make sense to do here:
  devm_iio_device_alloc(pdev->dev.parent, ...)

Currently it's:
  devm_iio_device_alloc(>dev, ...)

That would make it slightly more consistent.
i.e. the life-time of the object would be attached to the parent of the platform
device, versus the platform-device.

Currently, as it is, the allocation [of the IIO device] is tied the platform-
device, and the IIO registration to the parent (of the platform-device).
I'm not super-familiar with the internals here, but does this sound a bit wrong?
Is there a chance where the IIO device could be de-allocated, while registered?


> 
> > Signed-off-by: Alexandru Ardelean 
> > ---
> >  drivers/iio/light/lm3533-als.c | 1 -
> >  1 file changed, 1 deletion(-)
> > 
> > diff --git a/drivers/iio/light/lm3533-als.c b/drivers/iio/light/lm3533-als.c
> > index bc196c212881..0f380ec8d30c 100644
> > --- a/drivers/iio/light/lm3533-als.c
> > +++ b/drivers/iio/light/lm3533-als.c
> > @@ -852,7 +852,6 @@ static int lm3533_als_probe(struct platform_device
> > *pdev)
> > indio_dev->channels = lm3533_als_channels;
> > indio_dev->num_channels = ARRAY_SIZE(lm3533_als_channels);
> > indio_dev->name = dev_name(>dev);
> > -   indio_dev->dev.parent = pdev->dev.parent;
> > indio_dev->modes = INDIO_DIRECT_MODE;
> >  
> > als = iio_priv(indio_dev);
> 
> Johan
___
devel mailing list
de...@linuxdriverproject.org
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel


Re: [PATCH 4/5] iio: light: lm3533-als: remove explicit parent assignment

2020-05-29 Thread Johan Hovold
On Fri, May 22, 2020 at 11:22:07AM +0300, Alexandru Ardelean wrote:
> This assignment is the more peculiar of the bunch as it assigns the parent
> of the platform-device's device (i.e. pdev->dev.parent) as the IIO device's
> parent.
>
> It's unclear whether this is intentional or not.
> Hence it is in it's own patch.

Yeah, we have a few mfd drivers whose child drivers registers their
class devices directly under the parent mfd device rather than the
corresponding child platform device.

Since it's done consistently I think you need to update them all if you
really want to change this. 

And it may not be worth it since at least in theory someone could now be
relying on this topology.

> Signed-off-by: Alexandru Ardelean 
> ---
>  drivers/iio/light/lm3533-als.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/drivers/iio/light/lm3533-als.c b/drivers/iio/light/lm3533-als.c
> index bc196c212881..0f380ec8d30c 100644
> --- a/drivers/iio/light/lm3533-als.c
> +++ b/drivers/iio/light/lm3533-als.c
> @@ -852,7 +852,6 @@ static int lm3533_als_probe(struct platform_device *pdev)
>   indio_dev->channels = lm3533_als_channels;
>   indio_dev->num_channels = ARRAY_SIZE(lm3533_als_channels);
>   indio_dev->name = dev_name(>dev);
> - indio_dev->dev.parent = pdev->dev.parent;
>   indio_dev->modes = INDIO_DIRECT_MODE;
>  
>   als = iio_priv(indio_dev);

Johan
___
devel mailing list
de...@linuxdriverproject.org
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel