Re: time goes backwards periodically on laptop if booted in low-power mode

[Chris Friesen <cfriesen@nortelnetworks.com>]

Nick Craig-Wood wrote:
> 
> On Sun, Feb 17, 2002 at 08:34:20AM -0800, Dan Kegel wrote:
> > My Toshiba laptop (running stock Red Hat 7.2, kernel 2.4.7-10)
> > appears to suffer from a power management-related time hiccup: when
> > I boot in low-power mode, then switch to high-power mode,
> > time goes backwards by 10ms several times a second.
> > According to the thread
> >  Subject:  [PATCH]: allow notsc option for buggy cpus
> >  From:     Anton Blanchard <anton@linuxcare.com.au>
> >  Date:     2001-03-10 0:58:29
> >  http://marc.theaimsgroup.com/?l=linux-kernel&m=98418670406359&w=2
> > this can be fixed by disabling the TSC option, but there
> > ought to be a runtime fix.  Was a runtime fix ever put
> > together for this situation?
> 
> All the IBM thinkpads we have in the office have exactly this problem.
> The major symptom is that ALT-TAB goes wrong in the sawfish window
> manager oddly!
> 
> I made a patch to fix this (this is its first outing).  It stops
> do_gettimeofday reporting a time less than it reported last time.

I see a minor problem here...what happens if you want to reset your clock (for
whatever purpose) to a previous time?

Chris

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