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

Lukas Wunner
2025-02-26T09:10:50Z

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?

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/

Thanks,

Lukas