Re: [PATCH][2.6][5/5]Support for HPET based timer

[Vojtech Pavlik]

On Wed, Aug 20, 2003 at 01:08:56AM +0100, Jamie Lokier wrote:
> Vojtech Pavlik wrote:
> > On Tue, Aug 19, 2003 at 12:20:22PM -0700, Pallipadi, Venkatesh wrote:
> > 
> > > 5/5 - hpet5.patch - This can be a standalone patch. Without this
> > >                     patch we loose interrupt generation capability
> > >                     of RTC (/dev/rtc), due to HPET. With this patch
> > >                     we basically try to emulate RTC interrupt
> > >                     functions in software using HPET counter 1.
> > > 
> > 
> > This is very wrong IMO. We shouldn't try to emulate the RTC interrupt
> > for the kernel, instead the HPET should use native APIC interrupt
> > routing.
> 
> Even on those machines where APIC interrupts are not usable?
> (E.g. due to interactions with the SMM BIOS).

Well, I suspect the machines with HPET should better have usable APIC
interrupts, because you won't be able to use all the HPET timers then -
only two can be routed via the timer and RTC interrupts, the other need
to use APIC or direct FSB delivery.

-- 
Vojtech Pavlik
SuSE Labs, SuSE CR
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