clock problem

[Tom Evans]

On Fri, 2007-05-11 at 08:53 -0600, M. Warner Losh wrote:
> In message: <20070511110759.L700 at thinkpad.dieringer.dyndns.org>
>             Martin Dieringer <martin.dieringer at gmx.de> writes:
> : This is NOT a hardware problem. 1. I have this on 2 machines, 2. the
> : problem is solved by switching to ACPI instead of APM
> 
> It is a hardware problem.  APM + powerd changes the frequency of the
> TSC.  If the TSC is used as the time source, then you'll get bad
> timekeeping.  ACPI uses its own frequency source that is much more
> stable and independent of the TSC, so switching to it fixes the
> problem because you are switching the hardware from using a really bad
> frequency source with ugly steps to using a good frequency source w/o
> steps.
> 
> Warner

Surely that would imply that it is a software misconfiguration issue. If
the TSC is unreliable under fairly standard duties, and there exists an
alternate source that is reliable, surely that indicates the
manufacturer has identified a problem, and solved it with alternate
hardware.

The failure then to use the correct hardware is a software
misconfiguration.

Cheers

Tom
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