Re: [PATCH] usb: xhci: Tear down host on Reset Endpoint and Set TR Dequeue timeout

[Michal Pecio]

On Wed,  4 Nov 2026 09:36:08 +0000, Ambareesh Balaji wrote:
> 2) One real hang with the same symptom on the same controller type
> (kernel 7.3.1, tainted by out-of-tree DKMS modules). After a Focusrite
> Scarlett Solo logged "USB disconnect", usb_hub_wq stayed in D state
> for over 4 minutes in usb_kill_urb(), called from
> scarlett2_private_free() on the disconnect path. Nothing recovered it
> and only a reboot helped. There was no "xHCI host not responding to
> stop endpoint command" in the log.
> 
> Reset Endpoint and Set TR Dequeue Pointer timeouts are only reported
> through xhci_dbg(), so the missing message does not rule them out,
> but it does not confirm them either. I see USB audio hangs like this
> once or twice a month. I have enabled xHCI dynamic debug and tracing
> and will send what I capture if it happens again.

If this happens on real HW then it's a different thing. Having logs
of this anomaly would surely help untangling what happens there.

Were you seeing these issues before 7.3? That release made changes to
the handling of URBs on disconnected devices, which caused some people
problems even in absence of host controller bugs.

Regards,
Michal