Re: [PATCH v3] PCI: Skip Target Speed quirk on clamped ports with no link

Thorsten Leemhuis <[email protected]> Tue, 4 Aug 2026 07:32:53 +0200
Newsgroups org.kernel.vger.linux-pci,dev.linux.lists.regressions,org.kernel.vger.linux-kernel
Message-ID <[email protected]>
On 8/4/26 00:07, Maciej W. Rozycki wrote:
> On Mon, 3 Aug 2026, Thorsten Leemhuis wrote:
>>> Since commit 72780f796468 ("PCI: Always lift 2.5GT/s restriction in PCIe
>>> failed link retraining") the Target Speed quirk lifts a firmware-imposed
>>> 2.5GT/s restriction on any downstream port, without checking whether the
>>> link is up.  Where nothing is plugged in, the retraining that follows can
>>> never complete, so each attempt costs PCIE_LINK_RETRAIN_TIMEOUT_MS.  The
>>> quirk makes two of them -- the initial one and the restore on the error
>>> path -- adding a fixed 2 s to every boot.
>>
>> TWIMC, this patch fixes a regression Edward reported here:
>> https://bugzilla.kernel.org/show_bug.cgi?id=221801
> 
>  Thank you for the pointer.

yw
>  As it happens attempts were made to cc me on that bug, which however went 
> nowhere as messages were sent to my long-defunct <[email protected]> 
> e-mail address, a clear oversight of mine as I went, back in the day, 
> through numerous sites to get this updated.
> 
>  I have now asked bugzilla admins to help me recover my account.

FWIW, Artem does that and I'm not a fan of it at all -- I think it is
only appropriate when one knows the person occasionally interacts
directly (e.g. not via mail) with bugzilla (and thus I only do it in
those cases).
>> [side note: the report could be more specific, yes -- I wanted to ask
>> Edward to clarify a few things (like the actual slowdown) before
>> forwarding it, but it didn't came to that when I noticed this patch and
>> asked Edward to just check if it helped -- which is did.]
> 
>  Tested-by tags welcome!

FWIW, as I forgot to mention it easlier: Edward is CCed.

@Edward, if you'd like a record of your test result end up in the
history, reply with

 Tested-by: Full Name <email address>

to this thread, just omit the space in the beginning and change it
accordingly.

Ciao, Thorsten