Bug#816176: linux-image-4.3.0-0.bpo.1-amd64: xhci_hub_control causes abnormally high CPU usage when no USB devices attached

[Moritz Mühlenhoff <jmm@inutil.org>]

Am Tue, Sep 25, 2018 at 08:19:13PM +0200 schrieb Yves-Alexis Perez:
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> On Sun, 28 Feb 2016 12:19:43 +0100 Anders Nylander <randomsalad@gmail.com>
> wrote:
> 
> > Following the removal of of the USB device, I noticed very high CPU usage
> > being caused by kworker and ksoftirqd.
> > Using perf to log 10s of data and then reading the report, I noticed that
> > xhci_hcd/xhci_hub_control was generating a LOT of work for the kworker
> > (~42%).
> 
> I'm experiencing a very similar behavior on my ThinkPad X250 attached to a
> dock. It doesn't happen every time I resume, but quite often these days (on
> 4.18.8-1). Unplugging an USB3 disk plugged to the dock fixed the problem for
> me, and replugging it worked as well, so maybe there's some kind of loop I
> managed to break with that.
> 
> I also noticed https://bugzilla.redhat.com/show_bug.cgi?id=1325488 on the
> exact same setup, but there's no other info there.
> 
> I'll try to dig upstream, but unfortunately it's not that easily reproducible
> here.

Is that still an issue with current kernels?

Cheers,
        Moritz