On Wed, 2010-01-27 at 15:34 -0800, Yinghai Lu wrote: > On 01/27/2010 01:03 PM, Bjorn Helgaas wrote: > > On Wednesday 27 January 2010 01:50:12 pm Linus Torvalds wrote: > >> > >> On Wed, 27 Jan 2010, Bjorn Helgaas wrote: > >>> > >>> Without intel_bus.c, we essentially assume config 1 all the time. > >>> If we keep intel_bus.c and this patch for .33, things should work > >>> for configs 1 and 4. Adding support for config 4 is good. > >> > >> Quite frankly, is there any major downside to just disabling/removing > >> intel_bus.c for 2.6.33? If we're not planning on having it in the long run > >> anyway - or even if we are, but we can't be really happy about the state > >> of it as it would be in 2.6.33, not using it at all seems to be the > >> smaller headache. > >> > >> The machines that it helps are also the machines where you can fix things > >> up with 'use_csr', no? And they are pretty rare, and they didn't use to > >> work without that use_csr in 2.6.32 either, so it's not even a regression. > >> > >> Am I missing something? > > > > Only that when we added intel_bus.c, Yinghai reported that the reason > > was because a machine had a broken _CRS, so "pci=use_crs" wouldn't help. > > > > At the time, Windows hadn't been brought up on that box. My > > speculation is that by now, they've done that bringup and probably > > fixed the _CRS issue, so it might work now. > > > > If that's the case, we could drop intel_bus.c from .33 and just use > > "pci=use_crs" on those boxes until we can figure out how to turn it > > on automatically. > > BIOS fixed that problem already. but > 1. how to turn that pci=use_crs for that box automatically ? > how about our other kind of boxes? Yes, we need a way to turn on "pci=use_crs" automatically. My first thought is to turn it on for all BIOSes with dates of 2010 or later, and in addition, have a whitelist of the pre-2010 machines that require it. > 2. how about when apci is disabled? When ACPI is disabled, I think we just have to accept that we lose some functionality. I don't see the need for alternate ways to accomplish everything that ACPI does. It's becoming less and less useful to disable ACPI; I think it's only interesting as a debugging tool, and even then it's a sledgehammer. Bjorn -- 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
