On Fri, Jan 15, 2010 at 10:14:17AM -0800, Jesse Barnes wrote: > On Thu, 14 Jan 2010 16:39:13 -0800 > Yinghai Lu <yinghai@xxxxxxxxxx> wrote: > > > On 01/14/2010 03:49 PM, Bjorn Helgaas wrote: > > > On Thursday 14 January 2010 04:38:08 pm Yinghai Lu wrote: > > >> On 01/14/2010 03:09 PM, Bjorn Helgaas wrote: > > >>> On Thursday 14 January 2010 03:46:35 pm Yinghai Lu wrote: > > >>>> > > >>>> Bjorn pointed out we need to remove mmconf range > > >>>> > > >>>> Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx> > > >>>> > > >>>> --- ... > > >>> > > >>> This can't be right, can it? Let's say the kernel was built with > > >>> CONFIG_PCI_MMCONFIG turned off, or the user used "pci=nommconf", > > >>> or the kernel decides not to use MMCONFIG for some other reason. > > >>> > > >>> In that case, the hardware may still be configured to support > > >>> MMCONFIG, but the pci_mmcfg_list will be empty, so your code will > > >>> leave the window alone. We might assign some of that MMCONFIG > > >>> space to a device, but the hardware will route it to MMCONFIG, > > >>> not to the device. > > >> > > >> so if there is mmconf specified, we just skip the whole function? > > > > > > No, I'm saying that intel-bus.c must ALWAYS remove the MMCONFIG > > > region from the host bridge apertures, even if Linux isn't using > > > MMCONFIG. > > > > > > That means intel-bus.c has to be smart enough to figure out on its > > > own what the MMCONFIG area is. It can't depend on mmconfig-shared.c > > > to do it, because mmconfig-shared.c might not be there. > > > > that seems go too far away... > > > > Subject: [PATCH -v2] x86/pci: intel ioh need to subtrac mmconf range > > > > Bjorn pointed out we need to remove mmconf range > > > > -v2: if mmconf is not there, get out early. > > > > Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx> > > > > --- ... > > This goes against the real intent of intel_bus.c doesn't it? When we > first added it, the thought was that it would be a purely native way of > getting at bridge window information and not rely on firmware. If > you're going to make it dependent on MMCONFIG now, why not trust other > firmware tables as well, like _CRS? > > The MMCONFIG ranges are pretty easy to get at, the public docs have > info about the registers that control the MMCONFIG decode ranges, so > you should be able to read them out and add them to this file, > preserving the original intent. I did attempt a bisection last week, but my pared down config kept hitting a sysfs_create_file panic. I didn't succeed. Should I try the v2 patch above? What tree is it against? -Jeff -- 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
