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

[Thorsten Leemhuis]

On 9/18/26 01:33, Bjorn Helgaas wrote:
> On Sat, Aug 01, 2026 at 10:11:48PM +0200, Andreas Wild wrote:
>> From: "Maciej W. Rozycki" <macro@xxxxxxxxxxx>
>> 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.
>>
>> On an MSI PRO Z690-A WIFI DDR4 (Intel 600 Series PCH) with one empty x1
>> slot, running v7.2-rc5:
>> [...]
>> Fixes: 72780f796468 ("PCI: Always lift 2.5GT/s restriction in PCIe failed link retraining")
>> Cc: stable@xxxxxxxxxxxxxxx
>> Reported-by: Andreas Wild <andiwild@xxxxxxxxx>
>> Closes: https://lore.kernel.org/lkml/20260801092152.5643-1-andiwild@xxxxxxxxx/
>> Tested-by: Andreas Wild <andiwild@xxxxxxxxx>
>> Signed-off-by: Maciej W. Rozycki <macro@xxxxxxxxxxx>
>> Signed-off-by: Andreas Wild <andiwild@xxxxxxxxx>
> 
> I provisionally applied this on pci/misc.  It seems to address at
> least part of a v7.2 regression, so it probably should go on
> pci/for-linus for v7.3.
> 
> But I'd like to have it in -next for a bit before asking Linus to pull
> it. [...]

Great, thx -- and yes, -next sounds totally fine for me, as this fixes a
delay, not a hard breakage.
> But IIUC Aoxtj still sees issues with 72780f796468 ("PCI: Always lift
> 2.5GT/s restriction in PCIe failed link retraining") even with this
> patch
> (https://lore.kernel.org/all/331e97c7-e422-420d-9f3e-5d9f734464b3@xxxxxxxxxxx)
> 
> And M M / Mich (BCC'd) also reports an issue that (IIUC) is not fixed by
> this patch (https://bugzilla.kernel.org/show_bug.cgi?id=221919#c3)
> 
> So evidently there are still issues but maybe this patch fixes part of
> them?
Yeah, Maciej ten days expressed that we to look into this. Anyway, I
suggest someone that is affected by that problem starts a new thread
(please CC all those that are affected by it and the regression list)
with summarizing the current state + this patch, as this thread got a
bit confusing... (please drop a link to that thread here afterwards)

Ciao, Thorsten