[Bug 216373] New: Uncorrected errors reported for AMD GPU #forregzbot

[Thorsten Leemhuis]

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[TLDR: I'm adding this regression report to the list of tracked
regressions; all text from me you find below is based on a few templates
paragraphs you might have encountered already already in similar form.]

Hi, this is your Linux kernel regression tracker.

On 18.08.22 22:38, Bjorn Helgaas wrote:
> [Adding amdgpu folks]
> 
> On Wed, Aug 17, 2022 at 11:45:15PM +0000, bugzilla-daemon at kernel.org wrote:
>> https://bugzilla.kernel.org/show_bug.cgi?id=216373
>>
>>             Bug ID: 216373
>>            Summary: Uncorrected errors reported for AMD GPU
>>     Kernel Version: v6.0-rc1
>>         Regression: No
>> ...
> 
> I marked this as a regression in bugzilla.
> 
>> Hardware:
>> CPU: Intel i7-12700K (Alder Lake)
>> GPU: AMD RX 6700 XT [1002:73df]
>> Motherboard: ASUS Prime Z690-A
>>
>> Problem:
>> After upgrading to v6.0-rc1 the kernel is now reporting uncorrected PCI errors
>> for my GPU.
> 
> Thank you very much for the report and for taking the trouble to
> bisect it and test Kai-Heng's patch!
> 
> I suspect that booting with "pci=noaer" should be a temporary
> workaround for this issue.  If it, can you add that to the bugzilla
> for anybody else who trips over this?
> 
>> I have bisected this issue to: [8795e182b02dc87e343c79e73af6b8b7f9c5e635]
>> PCI/portdrv: Don't disable AER reporting in get_port_device_capability()
>> Reverting that commit causes the errors to cease.
> 
> I suspect the errors still occur, but we just don't notice and log
> them.
> 
>> I have also tried Kai-Heng Feng's patch[1] which seems to resolve a similar
>> problem, but it did not fix my issue.
>>
>> [1]
>> https://lore.kernel.org/linux-pci/20220706123244.18056-1-kai.heng.feng@canonical.com/
>>
>> dmesg snippet:
>>
>> pcieport 0000:00:01.0: AER: Multiple Uncorrected (Non-Fatal) error received:
>> 0000:03:00.0
>> amdgpu 0000:03:00.0: PCIe Bus Error: severity=Uncorrected (Non-Fatal),
>> type=Transaction Layer, (Requester ID)
>> amdgpu 0000:03:00.0:   device [1002:73df] error status/mask=00100000/00000000
>> amdgpu 0000:03:00.0:    [20] UnsupReq               (First)
>> amdgpu 0000:03:00.0: AER:   TLP Header: 40000001 0000000f 95e7f000 00000000
> 
> I think the TLP header decodes to:
> 
>   0x40000001 = 0100 0000 ... 0000 0001 binary
>   0x0000000f = 0000 0000 ... 0000 1111 binary
> 
>   Fmt           010b                 3 DW header with data
>   Type          0000b  010 0 0000    MWr Memory Write Request
>   Length        00 0000 0001b        1 DW
>   Requester ID  0x0000               00:00.0
>   Tag           0x00
>   Last DW BE    0000b                must be zero for 1 DW write
>   First DW BE   1111b                all 4 bytes in DW enabled
>   Address       0x95e7f000
>   Data          0x00000000
> 
> So I think this is a 32-bit write of zero to PCI bus address
> 0x95e7f000.
> 
> Your dmesg log says:
> 
>   pci 0000:02:00.0: PCI bridge to [bus 03]
>   pci 0000:02:00.0:   bridge window [mem 0x95e00000-0x95ffffff]
>   pci 0000:03:00.0: reg 0x24: [mem 0x95e00000-0x95efffff]
>   [drm] register mmio base: 0x95E00000
> 
> So this looks like a write to the device's BAR 5.  I don't see a PCI
> reason why this should fail.  Maybe there's some amdgpu reason?

I'd like to add to the tracking to ensure it's not forgotten.

#regzbot introduced: v5.19..v6.0-rc1 ^
https://bugzilla.kernel.org/show_bug.cgi?id=216373
#regzbot title: pci or amdgpu: Uncorrected errors reported for AMD GPU

Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)

P.S.: As the Linux kernel's regression tracker I deal with a lot of
reports and sometimes miss something important when writing mails like
this. If that's the case here, don't hesitate to tell me in a public
reply, it's in everyone's interest to set the public record straight.