Subject: Re: PCI memory space mapping on RD94/JC94
To: None <simonb@wasabisystems.com>
From: None <cgd@sibyte.com>
List: port-arc
Date: 06/24/2001 23:14:29
simonb@wasabisystems.com ("Simon Burge") writes:
> > I think just disabling expansion ROM is enough.
> 
> Very weird...

oh, i dunno.  8-)

even if having the expansion ROM enabled isn't the actual cause of the
problem being seen (not paid enough attention to even really know what
it is 8-), it's still not kosher to try to access the device through
other BARs with it enabled.

the PCI 2.2 spec, page 205 (section 6.2.5.2) says, about Expansion ROM
base address registers:

> In order to minimize the number of address decoders needed, a device
> may share a decoder between the Expansion ROM Base Address register
> and other Base Address Registers.  When expansion ROM decode is
> enabled, the decoder is used for accesses to the expansion ROM and
> device independent software must not access the device through any
> other Base Address registers.




cgd