Rene Herman wrote:
> 
> It's really going to have to be a known _un_used register and (the write 
> direction of) port 0x80 is used exactly for that reason. Port 0xed is a 
> known "alternate diagnostic port" used by Phoenix BIOSes at least but 
> Peter Anvin reported trouble with that one -- probably for the outb 
> direction but assuming that means something was in fact responding, we'd 
> have the same timing problem.
> 

Yes, for the outbound direction.

> I believe we have two "good" options:
> 
> 1) port 0xed was tested by the current reporter and found to be safe 
> (and provide slow enough timing). If DMI  based quirk hacks are 
> available soon enough we can switch 0x80 to 0xed based on it. Are they?

DMI is just a data structure parked in memory, so it should at least be 
theoretically possible to get to it.

	-hpa