Re: Flash Back -- kernel 2.1.111

Vojtech Pavlik
2002-02-24T21:40:38Z

On Sun, Feb 24, 2002 at 09:15:06PM +0000, Alan Cox wrote:

> > The previous code didn't distinguish the bus speed between different
> > busses and it doesn't do now as well.
> > It could be really helpfull to look at the patch actually. Don't you
> > think?
>
> I know what would actually help here, (the other code wasn't broken IMHO)
> and would clean this up properly for not just IDE. Add a bus_speed field
> to the struct pci_bus - that is where the info belongs and its the platform
> specific bus code that can find the bus speed out (if anyone)

I have some experimental IDE based code which can detect the PCI bus
speed by doing some IDE transfers and measuring the time it takes. It
isn't 100% reliable, though. I haven't found any other way to detect PCI
clock reliably, unfortunately it cannot be safely guessed from the CPU
clock or FSB clock or anything.

--
Vojtech Pavlik
SuSE Labs