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I have two machines with HPETs that support FSB/MSI routing, and both those work (they are newer machines). Then I have a 2-core AMD and a 2-core Intel core Duo that does not support this option (they are a couple of years old), that simply refuse to generate any interrupts from the HPET. I've tried legacy option, I've tried to specifically route to IOAPIC int 0 and 2, I've tried all kinds of int settings, but there is no interrupt from the HPET.

I know the 2-core AMD is kind of odd, because I couldn't make it work before either. However, when I still used APIC timer to schedule, I had everything working on it (disc, network, USB), but right now nothing works because I have no working timer. Windows XP seems to suggest that it is using the HPET in legacy-mode.

Any ideas? Somebody else that had trouble with HPET on "half-old" multicore PCs?

rdos wrote:Any ideas? Somebody else that had trouble with HPET on "half-old" multicore PCs?

I suggest to drop HPET support at all. Even if you manage to get it working, it won't generate precise interrupts. It's not as good as it's name suggests (I had troubles with HPET under linux and win as well, despite of their drivers were correct). APIC timer is more reliable.

Apparently HPETs were introduced in 2005 so are you sure your "half old" is not around that era.

p.s Don't feel bad, Linux did not support HPET until 2.6