ACPI issue with ASUS P5A motherboard on 5.2-RELEASE

[Kevin Oberman]

> From: Gregory Poudrel <chojin at chojin.info>
> Date: Sun, 18 Jan 2004 13:30:37 +0100
> Sender: owner-freebsd-current at freebsd.org
> 
> Hello,
> 
> I recently had some problems with my ASUS P5A motherboard (K6-II 350) on
> FreeBSD 5.2-RELEASE.
> In fact, I had GENERIC kernel installed and ACPI activated.
> 
> First problem:
> Time flow was incorrect. In fact, 1 second meaned 0.5 second for FreeBSD.
> Each minute I tested a ntpdate and there was 76 seconds difference.
> When I rebooted and check in BIOS, time was correct and flowed independently.

This is a known bug in the P5A. It's ACPI-Safe clock is broken and runs
at double speed. Use the TSC clock by putting the line:
kern.timecounter.hardware=TSC
into /etc/sysctl.conf.

> Second problem:
> on my LAN there is a gateway on FreeBSD 4.9-STABLE that manages the internet
> connection.
> 
> When I traceroute/ping anything on the net from my PC under 5.2, there was
> 120 ms latency between my gateway and my first hop (provider LNS).
> From any other PC of my LAN, there was normal 60 ms latency.
> I changed network cards of PC under 5.2, changed RJ45 connector... nothing
> changed.

I have not seen this on my P5A (K63-450). I have no idea what might be
causing it.

> I decided on boot to disactivate ACPI by setting hint.acpi.0.disabled to 1.
> No problem anymore, normal time flowing, normal ping.

Without ACPI, you have no ACPI-safe clock, so TSC is chosen.
-- 
R. Kevin Oberman, Network Engineer
Energy Sciences Network (ESnet)
Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab)
E-mail: oberman at es.net			Phone: +1 510 486-8634