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.
However, 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 a
result, regions #1..3 are inserted into the resource tree as if they were
consumers of the 0x0000-0xdfff regions, and devices that have resources in one
of these regions (e.g. 0x3f6 for legacy IDE) have a resource conflict - the
kernel does not initialize them.
The attached patch makes the code in coalesce_windows() instead ignore res1
(which is already dealt with), possibly expanding res2 instead. As res2 has
not been reached in the outer loop in coalesce_windows(), the code will then
check for overlaps of the just-expanded resource with the rest of the
resources.
Regards,
Alexey.
Hi all,
Could anybody review/commit the patch?
Regards,
Alexey.
On Thursday, September 12, 2013 05:19:16 pm Alexey Neyman wrote:
> 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.
> However, 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 a result, regions #1..3 are inserted into the
> resource tree as if they were consumers of the 0x0000-0xdfff regions, and
> devices that have resources in one of these regions (e.g. 0x3f6 for legacy
> IDE) have a resource conflict - the kernel does not initialize them.
>
> The attached patch makes the code in coalesce_windows() instead ignore res1
> (which is already dealt with), possibly expanding res2 instead. As res2 has
> not been reached in the outer loop in coalesce_windows(), the code will
> then check for overlaps of the just-expanded resource with the rest of the
> resources.
>
> Regards,
> Alexey.
[ +cc Bjorn Helgaas, Rafael Wysocki, linux-acpi ]
On 09/16/2013 12:41 PM, Alexey Neyman wrote:
> Hi all,
>
> Could anybody review/commit the patch?
LKML is a pretty general list and maintainers don't typically
trawl the list for more work to do. The get_maintainer script
can be used to help determine to whom to address a patch.
peter@thor:~/src/kernels/next$ ./scripts/get_maintainer.pl -f arch/x86/pci/acpi.c
Thomas Gleixner <[email protected]> (maintainer:X86 ARCHITECTURE...)
Ingo Molnar <[email protected]> (maintainer:X86 ARCHITECTURE...)
"H. Peter Anvin" <[email protected]> (maintainer:X86 ARCHITECTURE...)
[email protected] (maintainer:X86 ARCHITECTURE...)
Bjorn Helgaas <[email protected]> (commit_signer:5/8=62%)
"Rafael J. Wysocki" <[email protected]> (commit_signer:3/8=38%)
Feng Tang <[email protected]> (commit_signer:1/8=12%)
Yijing Wang <[email protected]> (commit_signer:1/8=12%)
Mike Yoknis <[email protected]> (commit_signer:1/8=12%)
[email protected] (open list)
Regards,
Peter Hurley
PS - You'll want to inline your patch as well because as you can see
replies don't include it.
> Regards,
> Alexey.
>
> On Thursday, September 12, 2013 05:19:16 pm Alexey Neyman wrote:
>> 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.
>> However, 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 a result, regions #1..3 are inserted into the
>> resource tree as if they were consumers of the 0x0000-0xdfff regions, and
>> devices that have resources in one of these regions (e.g. 0x3f6 for legacy
>> IDE) have a resource conflict - the kernel does not initialize them.
>>
>> The attached patch makes the code in coalesce_windows() instead ignore res1
>> (which is already dealt with), possibly expanding res2 instead. As res2 has
>> not been reached in the outer loop in coalesce_windows(), the code will
>> then check for overlaps of the just-expanded resource with the rest of the
>> resources.
>>
>> Regards,
>> Alexey.
[Resending without HTML part - sorry for possible duplicates]
As requested by Peter, resending the patch with ACPI/x86 maintainers CC'ed.
Short description:
Make coalesce_windows() handle multiple resource overlaps.
Signed-off-by: Alexey Neyman <[email protected]>
Regards,
Alexey.
On Monday, September 16, 2013 07:31:58 PM Peter Hurley wrote:
> [ +cc Bjorn Helgaas, Rafael Wysocki, linux-acpi ]
>
> On 09/16/2013 12:41 PM, Alexey Neyman wrote:
> > Hi all,
> >
> > Could anybody review/commit the patch?
>
> LKML is a pretty general list and maintainers don't typically
> trawl the list for more work to do. The get_maintainer script
> can be used to help determine to whom to address a patch.
>
> peter@thor:~/src/kernels/next$ ./scripts/get_maintainer.pl -f
> arch/x86/pci/acpi.c Thomas Gleixner <[email protected]> (maintainer:X86
> ARCHITECTURE...) Ingo Molnar <[email protected]> (maintainer:X86
> ARCHITECTURE...)
> "H. Peter Anvin" <[email protected]> (maintainer:X86 ARCHITECTURE...)
> [email protected] (maintainer:X86 ARCHITECTURE...)
> Bjorn Helgaas <[email protected]> (commit_signer:5/8=62%)
> "Rafael J. Wysocki" <[email protected]> (commit_signer:3/8=38%)
> Feng Tang <[email protected]> (commit_signer:1/8=12%)
> Yijing Wang <[email protected]> (commit_signer:1/8=12%)
> Mike Yoknis <[email protected]> (commit_signer:1/8=12%)
> [email protected] (open list)
>
> Regards,
> Peter Hurley
>
> PS - You'll want to inline your patch as well because as you can see
> replies don't include it.
>
> > Regards,
> > Alexey.
> >
> > On Thursday, September 12, 2013 05:19:16 pm Alexey Neyman wrote:
> >> 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.
> >> However, 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 a result, regions #1..3 are inserted into the
> >> resource tree as if they were consumers of the 0x0000-0xdfff regions, and
> >> devices that have resources in one of these regions (e.g. 0x3f6 for
> >> legacy
> >> IDE) have a resource conflict - the kernel does not initialize them.
> >>
> >> The attached patch makes the code in coalesce_windows() instead ignore
> >> res1
> >> (which is already dealt with), possibly expanding res2 instead. As res2
> >> has
> >> not been reached in the outer loop in coalesce_windows(), the code will
> >> then check for overlaps of the just-expanded resource with the rest of
> >> the
> >> resources.
> >>
> >> Regards,
> >> Alexey.