Messages in this thread | | | Subject | RE: [PATCH][2.6][5/5]Support for HPET based timer | Date | Thu, 21 Aug 2003 13:56:32 -0700 | From | "Pallipadi, Venkatesh" <> |
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> -----Original Message----- > From: Vojtech Pavlik [mailto:vojtech@suse.cz] > Indeed. The main problem, however, for me was to decide which > IRQ to use > for the HPET. The HPET has a big mask of allowable IRQs, the APIC has > many pins - so how to decide which one to use and if possible > not share > it with a PCI device?
This possibly can be done by selecting the pin that is not already programmed by setup_IO_APIC_irqs(), and do a manual setup_IO_APIC_irqs() on that, for HPET usage.
> That'd work probably. I don't believe there will ever be systems with > HPET and without a working IOAPIC. But, well, insane things do happen. > > As for the user disabling it, we could disable HPET then, > too. Anyway, I > agree with your proposal of first going for legacy mode and > doing native > mode later.
Thanks for all the comments/suggestions. I will work on using early ioremap in place of fixmap and resend the patch.
> (PS. It's a pretty stupid thing in the HPET spec to only be able to > gobble up BOTH the PIT and RTC interrupts and not separately.)
I totally agree with you. Just one additional bit would have solved the these problems. Also, I do not understand why RTC interrupts were overridden at all, when HPET cannot provide complete RTC functionality and it does not know anything about RTC time.
Thanks, -Venkatesh
> -- > Vojtech Pavlik > SuSE Labs, SuSE CR > - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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