Re: [Patch v2] Make PCI extended config space (MMCONFIG) a driver opt-in

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

On Fri, 2007-12-28 at 14:14 -0500, Loic Prylli wrote:
> 
> Not knowing whether there is any chipset with the visibility feature,
> but without the retry capability, and given that CRS is irrelevant for
> most Linux platforms (it only matters just after power-on, long before
> Linux is started in the common case),

"common case" I suppose in your mouth means desktop machines ? :-)

In the embedded world, I would expect CRS to be something that linux has
to deal with regulary. Maybe enable_crs should be moved to quirks on
those platforms who want it...

> This is mostly independant, allowing a PCIE->PCI-X bridge to generate
> CRS is a different bit (bit 15 of pcie->devctl on the bridge). FWIW,
> Linux does not seem to touch it, and it defaults to zero, so it does
> not
> seem like most current PCIE->PCI-X bridge will never generates a CRS
> (some BIOSes might do it, but not the couple of platforms I looked
> at).
> Again the choice of setting here seems something better left to the
> specific BIOS/embedded-code for a given platform.

Ok, I wasn't sure about that one.

Ben.