On Tue, 26 Jan 2010 10:21:29 -0800 Yinghai Lu <yinghai@xxxxxxxxxx> wrote: > On 01/26/2010 10:16 AM, Linus Torvalds wrote: > > > > > > On Tue, 26 Jan 2010, Bjorn Helgaas wrote: > >> > >> which IS big enough, and we know the bridge is in fact forwarding the > >> [mem 0xd0000000-0xdfffffff 64bit pref] region, because the Radeon works > >> when Jeff boots with "pci=use_crs". > > > > I bet it's a subtractive decode thing. Sure, it could be just another > > undocumented range register (does anybody have the datasheet for that > > thing?) but Intel tends to often have subtractive decode. > > > > That system in question has three PCI express root ports, but two of them > > have IO and memory disabled according to the lspci info. So maybe it's as > > simple as that "I/O Hub PCI Express Root Port 7" just catching anything > > that nobody else does, and the single IOH host chip doing the same? > > > >> I think we should remove intel_bus.c before .33. It's breaking boxes > >> and we don't know how to fix it. Even if we do find out how to fix it, > >> I think we should move toward using _CRS instead, because that's what > >> Windows uses and it's an easy way for the firmware to tell us about > >> platform quirks. > > > > I suspect that for 33 it is indeed best to just revert. But somebody is > > bound to have information on how the actual hardware works. Yinghai? > > I have asked intel if there is any bit that could be enabled the routing. > there is no info about for their documentations. I could probably dig something up in our confidential database, but this is the main problem with intel_bus.c. It'll always be behind with _CRS provides. Sure _CRS may be wrong sometimes, but it'll always work well enough to bring Windows up, so we ought not to ignore it. The underlying problems with our _CRS support still aren't fixed though, so switching that on for 2.6.33 isn't an option. -- Jesse Barnes, Intel Open Source Technology Center -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
