On Thursday, October 03, 2013 12:14:38 pm Bjorn Helgaas wrote: > On Mon, Sep 23, 2013 at 12:15 AM, Alexey Neyman <sti...@att.net> wrote: > > [Resending due to no response to the original message in a week] > > > > Hi all, > > > > I have a board with a BIOS bug that reports the following I/O port > > regions in _CRS on one of the host bridges: > > > > 0x0000-0x03af // #0 > > 0x03e0-0x0cf7 // #1 > > 0x03b0-0x03bb // #2 > > 0x03c0-0x03df // #3 > > 0x0000-0xdfff // #4 > > 0xf000-0xffff // #5 > > > > Obviously, region number #4 is erroneous as it overlaps with regions > > #0..3. The code in coalesce_windows() in arch/x86/pci/acpi.c attempts to > > recover from such kind of BIOS bugs by merging the overlapping regions. > > Current code expands region #0 to 0x0000-0xdffff and makes region #4 > > ignored. As a result, overlap of the expanded region #0 with regions > > #1..3 remains undetected (as the inner loop already compared them with > > region #0). As a result, regions #1..3 are inserted into the resource > > tree even though they overlap with adjusted region #0 - which later > > results in resource conflicts for PCI devices with IO ports in one of > > those regions (e.g., for an PCI IDE controller in legacy mode - which > > has port 0x3f6). The kernel then refuses to initialize these devices. > > > > The fix: instead of expanding res1 and ignoring res2, do the opposite. > > The res2 window is yet to be compared against all windows between res1 > > and res2 (regions #1..3 in the above example), so the resulting resource > > map will include just the expanded region - and will ignore any > > overlapping ones. > > > > Signed-off-by: Alexey Neyman <sti...@att.net> > > Can you please open a report at http://bugzilla.kernel.org, assign it > to drivers/pci, and attach a complete dmesg log?
https://bugzilla.kernel.org/show_bug.cgi?id=62511 I am not at liberty to disclose full hardware configuration of the board, as it is a proprietary prototype board not in production. I've provided the relevant messages from dmesg though. Regards, Alexey. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
