On 01/19/2010 11:42 AM, Jeff Garrett wrote: > 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? maybe later with -tip tree + pci/linux-next. YH -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
