From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bjorn Helgaas Subject: Re: [Bug #15124] PCI host bridge windows ignored (works with pci=use_crs) Date: Wed, 27 Jan 2010 14:03:40 -0700 Message-ID: <201001271403.41955.bjorn.helgaas@hp.com> References: <201001271345.54454.bjorn.helgaas@hp.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Linus Torvalds Cc: Jesse Barnes , Yinghai Lu , Jeff Garrett , "Rafael J. Wysocki" , Linux Kernel Mailing List , Kernel Testers List , Linux PCI , Myron Stowe , Matthew Garrett , Ingo Molnar 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. Bjorn