PEX 8111 PCI-Express to PCI Bridge and FreeBSD

[M. Warner Losh]

In message: <200712281304.47922.jhb at freebsd.org>
            John Baldwin <jhb at freebsd.org> writes:
: On Thursday 27 December 2007 08:16:59 am Konstantin Dimitrov wrote:
: > hello All,
: > 
: > as far as i understand the documentation of the PEX 8111 PCI
: > Express-to-PCI Bridge, which is freely available here:
: > 
: > http://www.plxtech.com/products/expresslane/pex8111.asp
: > 
: > it is "Fully Transparent PCI Express to PCI Bridge", but under FreeBSD
: > it doesn't seem to behave as transparent, i.e. it doesn't seem to work
: > well with the standard FreeBSD PCI-PCI bridge driver, because it's not
: > possible to read/write from/to the PCI IC behind PEX 8111.
: 
: Can you provide more detail on what you mean by read/write?  Can you not do 
: config space transactions to child devices of the bridge or can you not 
: access mapped BARs of child devices or what exactly?

Yes.  I believe this may be the 'classic' problem that we've seen
before: FreeBSD assumes that the BIOS assigned bridge resources and
none are assigned.  It may also be as simple as bus numbering.

Warner