[PATCH 1/3] iommu/ipmmu-vmsa: Remove some unused register declarations

Yoshihiro Shimoda yoshihiro.shimoda.uh at renesas.com
Tue Oct 15 05:17:25 UTC 2019


Hi Geert-san,

> From: Geert Uytterhoeven, Sent: Friday, October 11, 2019 9:11 PM
> 
> Hi Shimoda-san,
> 
> Thanks for your patch!
> 
> On Wed, Oct 9, 2019 at 10:27 AM Yoshihiro Shimoda
> <yoshihiro.shimoda.uh at renesas.com> wrote:
> > To support different registers memory mapping hardware easily
> > in the future, this patch removes some unused register
> > declarations.
> >
> > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh at renesas.com>
> 
> Reviewed-by: Geert Uytterhoeven <geert+renesas at glider.be>

Thank you for your review!

> While I can confirm the removed definitions are unused, they were
> still valid (but see comments below).
> Perhaps it would be better to add comments, to state clearly to which
> SoCs or SoC families they apply?  Or do you think this would be futile,
> and would add too much clutter to the source file in the near future?

I think adding comments to the declarations are better to avoid
incorrect implementation in the future. So, I'll make such an incremental patch.

> > --- a/drivers/iommu/ipmmu-vmsa.c
> > +++ b/drivers/iommu/ipmmu-vmsa.c
> > @@ -104,8 +104,6 @@ static struct ipmmu_vmsa_device *to_ipmmu(struct device *dev)
> >  #define IMCTR                          0x0000
> >  #define IMCTR_TRE                      (1 << 17)
> >  #define IMCTR_AFE                      (1 << 16)
> > -#define IMCTR_RTSEL_MASK               (3 << 4)
> 
> FWIW, this is valid for R-Car Gen2 only.  On R-Car Gen3, the field
> contains 3 bits.

That's correct.

Best regards,
Yoshihiro Shimoda

> Gr{oetje,eeting}s,
> 
>                         Geert
> 
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org
> 
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                 -- Linus Torvalds


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