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List:       linux-kernel
Subject:    Re: Wrong bogomips after plugging in AC power
From:       Peter Amstutz <tetron () student ! umass ! edu>
Date:       1999-10-31 16:56:54
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My laptop, an ARM TS3100 (Celeron 433) seems to do something like this.
Specifically, the system clock looses a lot of time, something like 10
minutes to the day.  I suspect that the system, when idle, automatically
underclocks for power/heat saving, thus somehow slowing down the system
time...  It's very annoying, since I have to constantly correct the system
time to my watch to get it to set correct timestamps and such.

On Fri, 29 Oct 1999, Pavel Machek wrote:

> Hi!
> 
> So I've now confirmed that my toshiba can speed-up its cpu under some
> circumstances. When it is powered up while batteries are low (<20%
> will work), it will start with cpu at 150MHz, and bogomips are
> computed accordingly.
> 
> If I plug it into AC power, it will speed up to 300MHz, but bogomips
> still have "slow" value. Therefore all udelays are wrong by factor of
> two -- udelay(50) will only wait approx. 25usec. That seems pretty
> dangerous to me. Maybe we need some other source of short loops?
> 
> 								Pavel 
> -- 
> I'm really pavel@ucw.cz. Look at http://195.113.31.123/~pavel.  Pavel
> Hi! I'm a .signature virus! Copy me into your ~/.signature, please!
> 

           ------------------ Peter Amstutz --------------------
           -------------- tetron@student.umass.edu -------------
           ------- http://www-unix.oit.umass.edu/~tetron -------
           -----------------------------------------------------


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