5.11.17: xhci_hcd 0000:0a:00.3: WARN Event TRB for slot 3 ep 12 with no TDs queued?

5.11.17: xhci_hcd 0000:0a:00.3: WARN Event TRB for slot 3 ep 12 with no TDs queued?

[Udo van den Heuvel]

Hello,

When 5.11.17 gives me a load of:

xhci_hcd 0000:0a:00.3: WARN Event TRB for slot 3 ep 12 with no TDs queued

What happened?
What can I do (to help) fix it?


Kind regards,
Udo

PS:

AMD Ryzen 5 3400G with Radeon Vega Graphics on Gigabyte X570 AORUS PRO 
running kernel.org w/ Fedora 34.

Re: 5.11.17: xhci_hcd 0000:0a:00.3: WARN Event TRB for slot 3 ep 12 with no TDs queued?

[Mathias Nyman]

Hi

On 2.5.2021 18.22, Udo van den Heuvel wrote:
> Hello,
> 
> When 5.11.17 gives me a load of:
> 
> xhci_hcd 0000:0a:00.3: WARN Event TRB for slot 3 ep 12 with no TDs queued
> 
> What happened?

Either your host is sending spurious events, or more likely this TD (transfer descriptor)
was already handled and given back by driver due some event mid TD.
Host still has this TD cached and generates events for last entry of TD after xhci driver gave it back.

> What can I do (to help) fix it?

First try 5.12 (just came out) It has some xhci driver changes in this area.

If that doesn't help please take dynamic debug logs and xhci traces:

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
< trigger the issue >
Send output of dmesg
Send content of /sys/kernel/debug/tracing/trace

Trace can be huge, dmesg helps me find the right place in trace.

Thanks
-Mathias

Re: 5.11.17: xhci_hcd 0000:0a:00.3: WARN Event TRB for slot 3 ep 12 with no TDs queued?

[Udo van den Heuvel]

On 03-05-2021 10:57, Mathias Nyman wrote:
>> When 5.11.17 gives me a load of:
>>
>> xhci_hcd 0000:0a:00.3: WARN Event TRB for slot 3 ep 12 with no TDs queued
>>
>> What happened?
> 
> Either your host is sending spurious events, or more likely this TD (transfer descriptor)
> was already handled and given back by driver due some event mid TD.
> Host still has this TD cached and generates events for last entry of TD after xhci driver gave it back.

It happened again without me really using USB. (i.e.: no plugging in/out 
of USB items)
Does that tell you anything?
The PC has USB keyboard/mouse, but also a connection to the USB hub in 
the monitor.

>> What can I do (to help) fix it?
> 
> First try 5.12 (just came out) It has some xhci driver changes in this area.

5.12.6 here...

I'll look into generating a trace.

Udo