Re: HPET enabled in BIOS, not presented as available_clocksource -- config, kernel code, &/or BIOS?

[PGNet Dev <pgnet.dev@gmail.com>]

On 5/13/17 10:41 AM, Randy Dunlap wrote:
> [adding HPET driver maintainer]

Thanks

> A couple of comments below...

>> In BIOS, HPET's enabled.
> 
> How about if you just boot Linux without Xen?  Does HPET show up then?

yes, it appears so:

cat devices/system/clocksource/clocksource0/available
   tsc hpet acpi_pm

>> 		[    8.491738] hpet_acpi_add: no address or irqs in _CRS
> 
> Above line marks a big failure. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

I suspected that's problematic.

In the non-Xen case

dmesg | grep -i hpet
   [    0.000000] ACPI: HPET 0x000000009E8298F8 000038 (v01 SUPERM 
SMCI--MB 01072009 AMI. 00000005)
   [    0.000000] ACPI: HPET id: 0x8086a701 base: 0xfed00000
   [    0.000000] clocksource: hpet: mask: 0xffffffff max_cycles: 
0xffffffff, max_idle_ns: 133484882848 ns
   [    0.000000] hpet clockevent registered
   [    0.144010] DMAR-IR: HPET id 0 under DRHD base 0xfed90000
   [    1.398047] hpet0: at MMIO 0xfed00000, IRQs 2, 8, 0, 0, 0, 0, 0, 0
   [    1.404226] hpet0: 8 comparators, 64-bit 14.318180 MHz counter
   [    1.412080] clocksource: Switched to clocksource hpet
   [    3.627234] rtc_cmos 00:02: alarms up to one month, y3k, 242 bytes 
nvram, hpet irqs