[PATCH] ARM: local timers: Allow boot CPU to have its timer running early

[Marc Zyngier]

On Thu, 2011-06-02 at 14:38 -0500, Rob Herring wrote:
> On 06/02/2011 11:56 AM, Marc Zyngier wrote:
> > On Thu, 2011-06-02 at 18:31 +0200, Jean-Christophe PLAGNIOL-VILLARD
> > wrote:
> >> On 15:03 Wed 01 Jun     , Marc Zyngier wrote:
> >>> Currently, the boot CPU has its local timer enabled long after
> >>> the delay loop has been calibrated. This makes it impossible to
> >>> boot a system that only uses local timers, like the A15.
> >>>
> >>> Use late_time_init hook to initialize the boot CPU local timer.
> >>> Since shmobile is already using this hook, add an ARM specific
> >>> arm_late_time_init hook that platforms can use instead.
> >>>
> >>> Cc: Paul Mundt<lethal at linux-sh.org>
> >>> Cc: Magnus Damm<magnus.damm at gmail.com>
> >>> Signed-off-by: Marc Zyngier<marc.zyngier at arm.com>
> >> I propose to switch to early platform devce and earlytimer
> >>
> >> this will avoid the arm_late_time_init hook
> >>
> >> and will make it cross arch
> >
> > I believe this is orthogonal. shmobile (the only ARM user of
> > late_time_init) is already doing some early_platform stuff for its
> > timers.
> >
> > What I'm trying to achieve here is to make sure the timer on CPU0 is
> > actually up, running and registered as a clock_event_device before we
> > hit the delay loop.
> >
> > Or maybe I've misunderstood what you're pointing me to?
> >
> 
> I believe he is referring to this patch which generically enables the 
> shmobile code for ARM:
> 
> http://www.spinics.net/lists/arm-kernel/msg123736.html

Ah, I see. With that patch, I can indeed loose the additional hook.

> I don't think it has been pulled into mainline yet.

I'll rebase my patch on top of this one if there's a consensus around
it.

Thanks,

	M.
-- 
Reality is an implementation detail.