Messages in this thread | | | Date | Thu, 16 Sep 2004 22:34:51 +0200 | From | Vojtech Pavlik <> | Subject | Re: device driver for the SGI system clock, mmtimer |
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On Thu, Sep 16, 2004 at 11:35:52AM -0700, Jesse Barnes wrote: > On Thursday, September 16, 2004 11:14 am, Vojtech Pavlik wrote: > > On Thu, Sep 16, 2004 at 09:09:12AM -0700, Jesse Barnes wrote: > > > On Thursday, September 16, 2004 9:03 am, Bjorn Helgaas wrote: > > > > Christoph Lameter wrote: > > > > > The timer hardware was designed around the multimedia timer > > > > > specification by Intel but to my knowledge only SGI has implemented > > > > > that standard. The driver was written by Jesse Barnes. > > > > > > > > As far as I can see, drivers/char/hpet.c talks to the same hardware. > > > > HP sx1000 machines (and probably others) also implement the HPET. > > > > > > No, it's different hardware. > > > > mmtimer and hpet are the same hardware actually, just a different > > specification revision, hpet being the newer one. > > Well, the SHub RTC hardware (which mmtimer accesses) isn't really HPET or > mmtimer hardware, but I tried to make the mmtimer *API* useful for HPET style > hardware. The idea was to have several drivers supporting the mmtimer API > with different hardware underneath.
Sorry, I got confused by the driver name.
> > HPET registers are MMIO so it's in theory possible, while not really > > useful if you're using it as your system timer as well. > > I don't think anyone does this.
x86-64 does if SMP is enabled and HPET is present.
-- 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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