Dear Michał,


Thank you for your reply.


Am 05.04.24 um 11:32 schrieb Michał Pecio:

>> On a Dell XPS 13 9360/0596KF, BIOS 2.21.0 06/02/2022 with Debian
>> sid/unstable, at least Linux 6.8-rc7 and 6.9-rc1+ log the error
>> below, when unplugging a USB headset from the USB Type A port of the
>> laptop.
> 
> Can you reproduce this on other computers or with other USB devices?

I have not tried it on another GNU/Linux system yet. It does *not* 
happen with a Plantronics Blackwire 315.1 USB headset.

> (I just tested a few random audio dongles on my PC, nothing happens).
> 
> Is there any kernel version known to be free of this problem?

Unfortunately no. It is reproducible with Debian’s Linux kernel 6.7.9-2. 
But in the available logs I found a 6.8+ (“6.9-rc0”) boot with no such 
error messages, but I forgot to save them between reboots now, and lost 
them. Sorry.

>>       xhci_hcd 0000:00:14.0: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 1 comp_code 1
>>       xhci_hcd 0000:00:14.0: Looking for event-dma 0000000128897080 trb-start 0000000128897090 trb-end 0000000128897090 seg-start 0000000128897000 seg-end 0000000128897ff0
> 
> This looks like the xHCI driver freed data structures related to a USB
> transfer concurrently with the hardware executing this transfer. It's
> a bad thing which should never happen, but sometimes it does because of
> bugs in USB controllers or the driver.

Interesting. Thank you for the analysis.

> Can you run patched kernels on the affected laptop? I attach a patch
> I used to track down similar issues on UVC webcams. It doesn't fix
> anything, but adds some dmesg noise which may be helpful in figuring
> out what goes wrong. The patch should work on v6.9-rc1 or -rc2.

Thank you. Please find the log attached with the patch applied on:

     $ git log --no-decorate --oneline -2
     627920e87b52 usb: xhci: Add debug prints
     6c6e47d69d82 Merge tag 'firewire-fixes-6.9-rc2' of 
git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394


Kind regards,

Paul