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Re: [PATCH 3/5] Deforest the function pointer jungle in the time code.

To: Franck Bui-Huu <vagabon.xyz@gmail.com>
Subject: Re: [PATCH 3/5] Deforest the function pointer jungle in the time code.
From: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Date: Tue, 19 Jun 2007 21:26:40 +0400
Cc: Atsushi Nemoto <anemo@mba.ocn.ne.jp>, ralf@linux-mips.org, macro@linux-mips.org, linux-mips@linux-mips.org
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Franck Bui-Huu wrote:

On Tue, 19 Jun 2007 09:33:33 +0200, "Franck Bui-Huu" <vagabon.xyz@gmail.com> wrote:
> What do you mean by "pnx8550 can have customized copy of cp0_hpt
> routines" ? Do you mean that it should copy the whole clock event
> driver ?

> It seems to me that using cp0 hpt as a clock event only is a valid usage...

Well, I thought the customized cp0 clockevent codes (custom
.set_next_event routine is needed anyway, isn't it?)

I don't think so.

hpt-cp0.c clock event part doesn't care if the counter is cleared when
an interrupt is triggered.

Well, in the generic case it must read back the Count reg. before writing to the Compare reg. and for PNX8550 this is unnecessary -- but indeed, should not harm...

It matters only for clock source (well I
think) that's why I suggested to rewrite a clock source driver only
for this platform...

Yeah, this platform certainly *needs* another clocksource than the counter used for the clock events -- currently it's count/compare 2. And this platform also *needs* a separate clocksource driver as well since the PNX8550 counters *do* support auto-reaload mode here -- in fact, this seems to be the only supported mode from the manual excerpt cited here:

http://www.linux-mips.org/archives/linux-mips/2006-12/msg00194.html

WBR, Sergei

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