Re: [PATCH] PCI: pciehp: Fix system hang on resume after hot-unplug during suspend

From: Lukas Wunner
Date: Tue Oct 01 2024 - 07:07:36 EST


On Mon, Sep 30, 2024 at 11:27:28AM +0800, AceLan Kao wrote:
> Lukas Wunner <lukas@xxxxxxxxx> 2024 9 27 5:28
> > there is a known issue
> > that a deadlock may occur when hot-removing nested PCIe switches (which is
> > what you've got here). Keith Busch recently re-discovered the issue.
> > You may want to try if the hang goes away if you apply this patch:
> >
> > https://lore.kernel.org/all/20240612181625.3604512-2-kbusch@xxxxxxxx/
> >
> > If it does go away then at least we know what the root cause is.
>
> Yes, the 2 patches work.

Okay so you can't reproduce the issue with those patches?

That would mean 9d573d19547b ("PCI: pciehp: Detect device replacement
during system sleep") isn't the culprit, whew!


> > The patch is a bit hackish, but there's an ongoing effort to tackle the
> > problem more thoroughly:
> >
> > https://lore.kernel.org/all/20240722151936.1452299-1-kbusch@xxxxxxxx/
> > https://lore.kernel.org/all/20240827192826.710031-1-kbusch@xxxxxxxx/
>
> v2 can't be applied clearly, so I made some changes.
> And this series doesn't work for me.

Okay, I'll look at those patches separately.

Thanks,

Lukas