[Patch ping #5] On Thursday, October 03, 2013 04:16:07 pm Alexey Neyman wrote: > 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.
Could anybody review/commit? 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/
