[PATCH] Use todc on Mot PReP platforms

Tom Rini trini at kernel.crashing.org
Fri Aug 12 05:43:07 EST 2005

On Wed, Aug 10, 2005 at 09:37:35AM -0700, Matt Porter wrote:

> This restores behavior from 2.4 where PReP platforms identified
> as Motorola would calibrate the decrementer using the RTC. On
> real Motorola PReP hardware this isn't needed. However, in order
> to boot a stock 2.6 PReP kernel on qemu (which emulates a Motorola
> PReP system) it is necessary to allow it to calibrate the decrementer
> using an emulated RTC.  If the decrementer rate is read from
> residual data then timing is screwed since a qemu PReP system typically
> runs much faster than the original hardware.
> If anybody has objections to this as the default, let me know. It
> still works (as did 2.4) on a couple of my Mot PReP boxes and doesn't
> affect the IBM PReP paths. My goal with this is to be able to run
> a stock 2.6 defconfig PReP build on qemu.

So, I like this, and not just because I'm playing with qemu as well.
Leigh, can you run this on any 'interesting' PReP you've got that might
tickle a bug here?  Thanks.

Tom Rini

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