Liu, Jiang wrote: > Li, Aubrey <> wrote: >> Bill.Holler wrote: >> >>>> Oh, oh..., that's right, we should use TSC. >>>> But since we will support platform on which TSC is not reliable in >>>> deep c-state, I suggest we use PM timer to make code a bit easier >>>> to readable, :- >>> >>> Do you recommend the HPET timer or the ACPI PM timer as a >>> reliable timer? We are currently investigating the HPET timer. >>> >> ACPI PM timer is already supported in the ACPICA. >> Take a look at $(SRC)/uts/intel/io/acpica/hardware/hwtimer.c >> PM timer is recommended in ACPI spec for deep c-state. >> But I think both can be used as a reliable source. > > If so, PM timer should be a better choice because it's more > standardized than HPET and PM timer with 250 precision should be > enough for C-state. >
What 250 precision means here? Thanks, -Aubrey
