Re: More info on port 80 symptoms on MCP51 machine.

H. Peter Anvin
2007-12-15T22:48:31Z

Allen Martin wrote:
>
> Nothing inside the chipset should be decoding port 80 writes. It's
> possible this board has a port 80 decoder wired onto the board that's
> misbehaving. I've seen other laptop boards with port 80 decoders
> wired onto the board, even if the 7 segment display is only populated
> on debug builds.
>
> We use PCI port 80 decoders internally for debugging quite often, so
> if there were some chipset issue related to port 80 it would have
> showed up a long time ago, and this is the first I've heard of
> hangs related to port 80 writes.
>

Presumably you have programmable decoders to trigger SMI? If not, then
they're probably doing the equivalent in a SuperIO chip or similar.

-hpa