Re: xhci_hcd 0000:00:14.0: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 1 comp_code 1

Paul Menzel
2024-04-08T16:42:49Z

[one addition]

Am 08.04.24 um 18:37 schrieb Paul Menzel:
> Dear Mathias, dear Michał,
>
>
> Thank you very much for your assistance.
>
>
> Am 08.04.24 um 09:17 schrieb Mathias Nyman:
>> On 7.4.2024 15.25, Michał Pecio wrote:
>>> This (and the absence of any earlier errors on the endpoint) looks
>>> like the hardware may be confirming a "successful" transfer twice or
>>> the driver may be processing one such confirmation twice.
>>
>> It's also possible this TD/TRB was cancelled due to the disconnect.
>> Could be that even if driver removes the TD from the list and cleans
>> out the TRB from the ring buffer (turns TRB to no-op) hardware may
>> have read ahead and cached the TRB, and process it anyway.
>>
>>> [   94.088594] usb 1-2: USB disconnect, device number 8
>>> [   94.089370] xhci_hcd 0000:00:14.0: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 1 comp_code 1
>>> [   94.089403] xhci_hcd 0000:00:14.0: Looking for event-dma 00000001250310f0 trb-start 0000000125031100 trb-end 0000000125031100 seg-start 0000000125031000 seg-end 0000000125031ff0
>>> [   94.089427] xhci_hcd 0000:00:14.0: last xhci_td_cleanup: first_dma 1250310f0 last_dma 1250310f0 status -115 from finish_td
>>>
>>> (I say "successful" but it really isn't - the device is no longer
>>> listening. But there is no delivery confirmation on isochronous OUT
>>> endpoints so the xHC doesn't suspect anything.)
>>>
>>> Could you try again with this updated debug patch to get more info?
>>
>> Would also be helpful to add xhci dynamic debug and xhci tracing (two
>> separate logs). These will show in detail everything that is going on.
>>
>> Steps:
>>
>> mount -t debugfs none /sys/kernel/debug
>> echo 'module xhci_hcd =p' >/sys/kernel/debug/dynamic_debug/control
>> echo 'module usbcore =p' >/sys/kernel/debug/dynamic_debug/control
>> echo 81920 > /sys/kernel/debug/tracing/buffer_size_kb
>> echo 1 > /sys/kernel/debug/tracing/events/xhci-hcd/enable
>> echo 1 > /sys/kernel/debug/tracing/tracing_on
>> < Reproduce issue >
>> Send output of dmesg
>> Send content of /sys/kernel/debug/tracing/trace
>>
>> please copy the /sys/kernel/debug/tracing/trace file somewhere as soon
>> as possible after reproducing the issue. It grows fast.
>
> For posterity I created Linux Kernel Bugzilla issue #218695 [1], and
> attached the files there. Hopefully everything was captured, that you
> need. The discussion could continue on this list, but do as it suits you
> best.

Just to clarify, although there are six error log lines I only plugged
and unplugged the USB headset once.

> Kind regards,
>
> Paul
>
>
> [1]: https://bugzilla.kernel.org/show_bug.cgi?id=218695