Re: kernel: xhci_hcd 0000:00:14.0: ERROR unknown event type 37 - Kernel 4.19.13

[Nathan Royce]

You can ignore the last set of files with a sample of 1.
I got a nice sample of like 150 about 6 hours ago.
The link I included in the previous reply contains the same filenames,
just updated.
The journal timestamps (to correspond with the trace times) go from
"[513438.430253] computername kernel: xhci_hcd 0000:00:14.0: ERROR
unknown event type 37"
to
"[513438.796965] computername kernel: xhci_hcd 0000:00:14.0: ERROR
unknown event type 37"
That's 150 of them in less than 1/2 second.

On Wed, Jan 2, 2019 at 5:32 AM Mathias Nyman
<mathias.nyman@xxxxxxxxxxxxxxx> wrote:
>
> The event type 37 is a host controller event, most likely a event ring full error.
>
> So there are probably so many events that we fill the event ring before we can handle them.
>
> Could you take traces of this?
> Note that the trace file will be huge.
>
> mount -t debugfs none /sys/kernel/debug
> echo 81920 > /sys/kernel/debug/tracing/buffer_size_kb
> echo 1 > /sys/kernel/debug/tracing/events/xhci-hcd/enable
>
> copy the traces somewhere safe once the error is triggered:
> cp /sys/kernel/debug/tracing/trace  /<somewhere>
>
> -Mathias