Re: [PATCH v5 2/2] media: i2c: add Himax HM1246 image sensor driver

[Andy Shevchenko <andriy.shevchenko@linux.intel.com>]

On Wed, Nov 05, 2025 at 05:53:30AM +0000, Tarang Raval wrote:

...

> > > +static inline struct hm1246 *to_hm1246(struct v4l2_subdev *sd)

> > > +     return container_of_const(sd, struct hm1246, sd);
> >
> > It's unclear and confusing that _const() variant is used here.
> > Either const qualifier is missed somewhere, or _const is redundant.
> 
> The use of container_of_const() here is intentional and follows the direction 
> taken across multiple recent sensor drivers suggested by Sakari. 
> (e.g. ov2735, vd56g3, vd55g1, ov64a40, imx283).
> 
> AFAIK, using container_of_const() is a no-op for non-const 
> arguments,

I believe you want to say that it has no additional effect on the result or so.
Because it may not be a no-op, otherwise code won't work as expected.

> but keeps the helper type-safe and future-proof against 
> possible changes in the V4L2 API. This also maintains consistency with 
> other upstream drivers and avoids subtle warnings if any of the subdev 
> Callbacks later become const-qualified.



-- 
With Best Regards,
Andy Shevchenko