Re: Wrong bogomips after plugging in AC power

[Harald Koenig]

On Oct 29, 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.

at least for the Tecra 750/780 you can cycle though these 3 power modi
(fast/economy/user settings) using Fn-F2.

> 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

or 100 usec if you boot in fast mode and later switch to slow mode...

> dangerous to me. Maybe we need some other source of short loops?

would be `nice to have';)  but how/when do check/realize that you
have to recalibrate your delay loop ?  all real time clock sources 
are pretty slow/bad and have slow access, and most likely rdtsc 
will be clocked down too:(


Harald
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