Messages in this thread | | | Date | Sat, 12 Jan 2008 20:42:48 -0800 | From | Arjan van de Ven <> | Subject | Re: [Patch v2] Make PCI extended config space (MMCONFIG) a driver opt-in |
| |
On Sat, 12 Jan 2008 20:36:59 -0500 Tony Camuso <tcamuso@redhat.com> wrote:
> Thanks, Arjan. > > The problem we have been experiencing has to do with Northbridges, > not with devices.
correct for now. HOWEVER, and this is the point Linus has made several times: Just about NOBODY has devices that need the extended config space. At all. So making this opt-in for devices allows our users to boot and use their system if they are in the majority that has no need for even getting close to this mess.
> > As far as the device is concerned, after the Northbridge translates > the config access into PCI bus cycles, the device has no idea what > mechanism drove the Northbridge to the translation.
Wanne bet there'll be devices that screw this up? THere's devices that even screwed up the 64-256 region after all.
> The patch I devised concerned itself with Northbridges and separated > MMCONFIG-compliant buses from those that could not handle MMCONFIG.
THis kind of patchup has been going on for the better part of a year (well 2 years) by now and it's STILL NOT ENOUGH, as you can see by the more patchups that have been proposed as "alternative" to my approach.
> > In my humble opinion, Port IO config access is here to stay, having > been defined as an architected mechanism in the PCI 2.1 spec. > > This is most especially true for x86. > > In other words, for x86, I don't think we need to worry about Port > IO config access ever going away at all.
You're wrong there. Sad to say, but you're wrong there.
-- If you want to reach me at my work email, use arjan@linux.intel.com For development, discussion and tips for power savings, visit http://www.lesswatts.org
| |