Re: [PATCH/RFC] ARM: Rename ARCH_SHMOBILE to ARCH_SHMOBILE_LEGACY

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Magnus,

On Thursday 07 November 2013 15:04:57 Magnus Damm wrote:
> On Thu, Nov 7, 2013 at 8:54 AM, Laurent Pinchart wrote:
> > SH-Mobile platforms are transitioning from non-multiplatform to
> > multiplatform kernel. A new ARCH_SHMOBILE_MULTI configuration symbol has
> > been created to group all multiplatform-enabled SH-Mobile SoCs. The
> > existing ARCH_SHMOBILE configuration symbol groups SoCs that haven't
> > been converted yet.
> > 
> > This arrangement works fine for the arch/ code, but lots of drivers
> > needed on both ARCH_SHMOBILE and ARCH_SHMOBILE_MULTI depend on
> > ARCH_SHMOBILE only. In order to avoid changing them, rename
> > ARCH_SHMOBILE to ARCH_SHMOBILE_LEGACY, and create a new boolean
> > ARCH_SHMOBILE configuration symbol that is selected by both
> > ARCH_SHMOBILE_LEGACY and ARCH_SHMOBILE_MULTI.
> > 
> > Signed-off-by: Laurent Pinchart
> > <laurent.pinchart+renesas@ideasonboard.com>
> 
> Thanks, this looks good to me.
> 
> Acked-by: Magnus Damm <damm@opensource.se>

Thank you.

> I have one semi-related question below:
> > @@ -1619,7 +1621,7 @@ config HZ_FIXED
> >         default 200 if ARCH_EBSA110 || ARCH_S3C24XX || ARCH_S5P64X0 || \
> >                 ARCH_S5PV210 || ARCH_EXYNOS4
> >         default AT91_TIMER_HZ if ARCH_AT91
> > -       default SHMOBILE_TIMER_HZ if ARCH_SHMOBILE
> > +       default SHMOBILE_TIMER_HZ if ARCH_SHMOBILE_LEGACY
> >         default 0
> >  
> >  choice
> 
> For the hunk above, it makes sense that we cannot HZ in the multiplatform
> case, so I think your patch is right.
> 
> I do however wonder what's the plan with multiplatform and the HZ value, how
> do we handle hardware platforms that use 32768 Hz as clock?
> Historically those platforms work best with a even-divide-by-a-power-of-two
> HZ value, so with a HZ\x100 value things may drift slowly...

Good question. Would it make sense to allow freely selected HZ values on 
multiplatform kernels ? Or maybe only if if ARCH_SHMOBILE is selected ? Or 
maybe full tickless kernels are the solution :-)

-- 
Regards,

Laurent Pinchart