Re: PROBLEM: memory corruption with i815 chipset variant

[Alan Cox]

On Mon, 2002-05-27 at 09:11, Nicolas Aspert wrote:
> Alessandro reported the problem to me also. I went through the i815 
> specs and found 2 'strange' things (maybe they are not but...)
> 1) No 'ERRSTS' register (well... a bus that does no error should be a 
> feature ;-)
> 2) The ATTBASE register to which the *_configure functions write is 
> different from other Intel chipsets. In the i815, the ATT base adress 
> should be written between bits 12 and 28, whereas in all other Intel 
> chipsets, it should be written between bits 12 and 31 (don't ask me why 
> Intel feels like changing the adresses/specs for registers at each new 
> chipsets....) .
> Alan, do you think this could cause all those troubles ?

It certainly could be. If bits 29-31 maybe control things like memory
timings then it could do quite horrible things. Fixing it to leave the
ERRSTS register alone and keep bits 29-31 is definitely worth trying. If
that fixes it then its going to be easy enough to drop a fix into the
mainstream code

Alan