Re: Ask for a regression issue of vfio-pci driver with Intel DG2 (A770) discrete graphics card from Linux 6.1

["Linux regression tracking #adding (Thorsten Leemhuis)" <regressions@leemhuis.info>]

[CCing the regression list, as it should be in the loop for regressions:
https://docs.kernel.org/admin-guide/reporting-regressions.html]

[TLDR: I'm adding this report to the list of tracked Linux kernel
regressions; the text you find below is based on a few templates
paragraphs you might have encountered already in similar form.
See link in footer if these mails annoy you.]

On 03.07.23 12:37, Gwan-gyeong Mun wrote:
> 
> Since Linux 6.2 kernel (same happens in Linux 6.4.1), loading vfio-pci
> driver to a specific HW (Intel DG2 A770) target does not work properly.
> (It works fine on Linux 6.1 kernel with the same HW).
> 
> The configuration and hardware information used is described in [1].
> 
> Starting with the Linux 6.2 kernel, the following log is output to dmesg
> when a problem occurs.
> ...
> [ 15.049948] pcieport 0000:00:01.0: Data Link Layer Link Active not set
> in 1000 msec
> [ 15.050024] pcieport 0000:01:00.0: Unable to change power state from
> D3cold to D0, device inaccessible
> [ 15.051067] pcieport 0000:02:01.0: Unable to change power state from
> D3cold to D0, device inaccessible
> [ 15.052141] pcieport 0000:02:04.0: Unable to change power state from
> D3cold to D0, device inaccessible
> [ 17.286554] vfio-pci 0000:03:00.0: not ready 1023ms after resume;
> giving up
> [ 17.286553] vfio-pci 0000:04:00.0: not ready 1023ms after resume;
> giving up
> [ 17.286576] vfio-pci 0000:03:00.0: Unable to change power state from
> D3cold to D0, device inaccessible
> [ 17.286578] vfio-pci 0000:04:00.0: Unable to change power state from
> D3cold to D0, device inaccessible
> ...
> 
> And if you check the DG2 hardware using the "lspci -nnv" command, you
> will see that "Flags:" is displayed as "!!! Unknown header type 7f" as
> shown below. [2]
> The normal output log looks like [3].
> 
> This issue has been occurring since the patch below was applied. [4]
> 
> d8d2b65a940bb497749d66bdab59b530901d3854 is the first bad commit
> commit d8d2b65a940bb497749d66bdab59b530901d3854
> Author: Bjorn Helgaas <bhelgaas@google.com>
> Date:   Fri Dec 9 11:01:00 2022 -0600
> 
>     PCI/portdrv: Allow AER service only for Root Ports & RCECs
> 
> 
> Rolling back the [4] patch makes it work on boot with the latest version
> of the kernel, but the same problem still occurs after "suspend to s2idle".
> This problem existed even before applying [4].
> [...]

Thanks for the report. To be sure the issue doesn't fall through the
cracks unnoticed, I'm adding it to regzbot, the Linux kernel regression
tracking bot:

#regzbot ^introduced d8d2b65a940bb4
#regzbot title PCI/portdrv: vfio-pci driver fails to work with Intel DG2
(A770) discrete graphics
#regzbot ignore-activity

This isn't a regression? This issue or a fix for it are already
discussed somewhere else? It was fixed already? You want to clarify when
the regression started to happen? Or point out I got the title or
something else totally wrong? Then just reply and tell me -- ideally
while also telling regzbot about it, as explained by the page listed in
the footer of this mail.

Developers: When fixing the issue, remember to add 'Link:' tags pointing
to the report (the parent of this mail). See page linked in footer for
details.

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