RE: [PATCH 3/4] rtc: Introduce devm_rtc_allocate_device_priv

[Peng Fan]

Hi Dan,

> Subject: Re: [PATCH 3/4] rtc: Introduce devm_rtc_allocate_device_priv
> 
> On Mon, Jan 20, 2025 at 10:25:35AM +0800, Peng Fan (OSS) wrote:
> >  int __devm_rtc_register_device(struct module *owner, struct
> > rtc_device *rtc) diff --git a/drivers/rtc/dev.c b/drivers/rtc/dev.c
> > index
> >
> c4a3ab53dcd4b7280a3a2981fe842729603a1feb..e0e1a488b795645d
> 7c9453490d6c
> > dba510cc5db5 100644
> > --- a/drivers/rtc/dev.c
> > +++ b/drivers/rtc/dev.c
> > @@ -410,7 +410,8 @@ static long rtc_dev_ioctl(struct file *file,
> >  		}
> >  		default:
> >  			if (rtc->ops->param_get)
> > -				err = rtc->ops->param_get(rtc-
> >dev.parent, &param);
> > +				err = rtc->ops->param_get(rtc->priv ?
> > +							  &rtc->dev :
> rtc->dev.parent, &param);
> 
> This seems kind of horrible...  I can't think of anywhere else which does
> something like this.
> 
> It would almost be better to do something like:
> 
> 	err = rtc->ops->param_get(rtc->priv ? (void *)rtc : rtc-
> >dev.parent, &param);
> 
> The advatange of this is that it looks totally horrible from the get go
> instead of only subtly wrong.  And it would immediately crash if you
> got it wrong implementing the ->param_get() function pointer.

Thanks for help improving the code. I will include this in V2 and post
out after we reach a goal on how to support the 2nd RTC on i.MX95.

Thanks,
Peng.

> 
> regards,
> dan carpenter