Date: Fri, 21 Nov 2008 09:06:11 +0100
From: Ingo Molnar <mingo@elte.hu>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Dimitri Sivanich <sivanich@sgi.com>, Thomas Gleixner <tglx@linutronix.de>,
       linux-kernel@vger.kernel.org, Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH 0/2 v3] SGI RTC: add clocksource/clockevent driver and
	generic timer vector
Message-ID: <20081121080610.GG16242@elte.hu>
References: <20081023163041.GA14574@sgi.com> <20081119212202.GA3377@sgi.com> <20081120095943.GF6885@elte.hu> <49261276.10408@zytor.com>
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* H. Peter Anvin <hpa@zytor.com> wrote:

> Ingo Molnar wrote:
> > * Dimitri Sivanich <sivanich@sgi.com> wrote:
> > 
> >> The following patches provide a driver for synchronized RTC 
> >> clocksource and clockevents for SGI systems, as well as a generic 
> >> timer system interrupt.
> >>
> >> With these patches, a module can be installed that registers the 
> >> system-wide synchronized RTC clocksource and timers as both a 
> >> clocksource and clockevents device running in high resolution mode.
> >>
> >> [PATCH 1/2 v3] SGI RTC: add clocksource driver
> >> [PATCH 2/2 v3] SGI RTC: add generic timer system interrupt
> > 
> > Looks very clean and well-done to me.
> > 
> > I had to take a good look at the rtc_timer_head->expires[] construct - 
> > but i guess that's the best approach, as the max number of entries is 
> > hard to judge at build time. (and we wont get any real limit 
> > protection from gcc anyway)
> > 
> > Thomas, any objections?
> 
> I have *extremely* serious reservations about reserving even more 
> hardware vectors for SGI only.  This affects all systems, and quite 
> frankly should not be necessary at all.
> 
> The SGI UV people have pushed this at a number of points in the 
> past, and we have told them to use an irqchip instead.  This patch 
> tries to allocate yet another reserved vector, instead.

ah, yes, i suggested that in the past. And i was _so_ happy that this 
driver wasnt calling into the BIOS anymore but talking straight to the 
hardware ;-)

it shouldnt be hard to define a proper irqchip here.

	Ingo
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