Re: [Qemu-devel] [PATCH 3/4] Add support for HPET periodic timer.

Dan Kenigsberg
2007-08-22T21:11:50Z

On Wed, Aug 22, 2007 at 02:34:24PM +0200, Andi Kleen wrote:
> On Wed, Aug 22, 2007 at 10:03:32AM +0300, Avi Kivity wrote:
> > Maybe the kernel is using the timer, so userspace can't. Just a guess.
>
> HPET has multiple timers (variable, but typically 2 or 4). The kernel
> only uses timer 0. It's possible someone else in user space is using
> it though. Try lsof /dev/hpet

Thanks for the ideas; however even after I made the kernel use tsc as
time source, and made sure that no one opens /dev/hpet, I fail to use
HPET (with same errors as before)

I now have

$ dmesg |grep -i hpet
ACPI: HPET 7D5B6AE0, 0038 (r1 A M I OEMHPET 5000708 MSFT 97)
ACPI: HPET id: 0x8086a301 base: 0xfed00000
hpet0: at MMIO 0xfed00000, IRQs 2, 8, 0, 0
hpet0: 4 64-bit timers, 14318180 Hz
hpet_resources: 0xfed00000 is busy

Any other idea?

Dan.