Messages in this thread | | | Date | Sat, 28 Oct 2006 21:57:39 +0200 | From | Vojtech Pavlik <> | Subject | Re: AMD X2 unsynced TSC fix? |
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On Sat, Oct 28, 2006 at 02:22:11PM -0400, Lee Revell wrote:
> On Fri, 2006-10-27 at 20:59 -0700, Andi Kleen wrote: > > > Fortunately, we usually have an HPET, these days. You can > > definitely > > > resync and get near-linear values of RDTSC. > > > > No we don't -- most BIOS still don't give us the HPET table > > even when it is there in hardware. In the future this will change sure > > but people will still run a lot of older motherboards. > > I have exactly such a system (see thread "x86-64 with nvidia MCP51 > chipset: kernel does not find HPET"). Is there anything at all I can do > to make the kernel see the HPET? Can I try to guess the address? BIOS > upgrade?
In most cases where the HPET is present but not reported, it's not configured. Usually, you need to write a chipset-specific register to configure the address.
Finding the register, finding some free MMIO space, writing the address to the register and telling the address to the kernel is enough.
-- Vojtech Pavlik Director SuSE Labs - 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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