Subject: Re: Clock 3x too fast on AMD64 laptop [WAS Re: Various issues
	after rebooting]
From: Olivier Fourdan <fourdan@xfce.org>
To: john stultz <johnstul@us.ibm.com>,
       Dominik Brodowski <linux@dominikbrodowski.net>
Cc: lkml <linux-kernel@vger.kernel.org>
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Organization: http://www.xfce.org
Date: Thu, 31 Mar 2005 21:12:37 +0200
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Hi John, Dominik,


On Tue, 2005-03-29 at 14:11 -0800, john stultz wrote:
> Yea. From your description this is most likely the cause of the issue.
> Currently the time of day is still tick-based, using the tsc/pmtmr/hpet
> only for interpolating between ticks. 

Sorry for the late follow up. Unfortunately, a quick hack to disable the
"pmtmr" check shows that even when "trusting" the PM-Timer, the clock
and interrupts still run 3x too fast. That makes no difference.

> Well, if you tried the time of day re-work I've been working on it would
> mask the issue somewhat, but you'd still have the problem that you are
> taking too many timer interrupts.

Where could I get that patch from ? I'd be glad to do some testing for
you if you need it.

> One thing you could try is playing with the CLOCK_TICK_RATE value to see
> if you just have very unique hardware. 

Problem is that the issue shows exactly after one quick power off/power
on sequence. It doesn't show after a real cold start (leaving the laptop
off for a  couple of hours) or even after a reboot.

> A similar sounding issue has also been reported here:
> http://bugme.osdl.org/show_bug.cgi?id=3927

Not sure if that's the exact same problem. What I can say, after reading
that bug report, is that disabling ACPI and/or APIC makes no difference.
Specifying the clock=... makes no difference either. It doesn't seem
related to the AMD64 part of the kernel since it shows equally when
using a 64bit kernel and a 32bit kernel.

Moreover, when that bug shows, there are other different problems
showing (such as the cdrom not being to mount anything, or ndiswrapper
crashing the system with a MCE error).

At first, I thought the issue might be related to the nforce3, but the
bug refers to an ATI chipset so I guess it's not related to the nforce.

Anyway, it doesn't seem to be an uncommon issue with AMD64 based
hardware. I don't know where to start from though.

Cheers,
Olivier.


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