Re: diagnosing resume failures after disconnected USB4 drives (Was: Re: PCI/ASPM: Fix L1SS saving (linus/master commit 7507eb3e7bfac))

Mika Westerberg
2025-02-26T09:20:04Z

On Wed, Feb 26, 2025 at 10:10:43AM +0100, Lukas Wunner wrote:
> On Wed, Feb 26, 2025 at 10:44:04AM +0200, Mika Westerberg wrote:
> > [Meteor Lake host] <--> [TB 4 dock] <--> [TB 3 NVMe]
> [...]
> > I added "no_console_suspend" to the command line and the did sysrq-w to
> > get list of blocked tasks. I've attached it just in case it is needed.
> [...]
>
> This looks like the deadlock we've had for years when hot-removing
> nested hotplug ports.
>
> If you attach only a single device to the host, I guess the issue
> does not occur, right?

Yes.

> Previous attempts to fix this:
>
> https://lore.kernel.org/all/4c882e25194ba8282b78fe963fec8faae7cf23eb.1529173804.git.lukas@wunner.de/
>
> https://lore.kernel.org/all/20240612181625.3604512-1-kbusch@meta.com/

Well, it does not happen if I revert the commit so isn't that a
regresssion?