Subject: bug#34176: X200 kernel panic on S3 resume (linux-libre > 4.18.9)

From: Mike Gerwitz <[email-masked]>
Date: Sun, 27 Jan 2019 10:34:11 -0500

On Wed, Jan 23, 2019 at 01:08:39 -0500, Mike Gerwitz wrote:
> Right after sending this message, I recalled that I used powertop to do
> "auto tuning".  Sure enough, one of the lines was this:
>
>    Good          Autosuspend for USB device UHCI Host Controller [usb6]
>
> By disabling it, it runs this command:
>
>   echo on > /sys/bus/usb/devices/usb6/power/control
>
> And it resolves my suspend issues on 4.20.3-gnu.

[...]

> This bug can be closed.

Sorry, I take that back.  I could have sworn it did resolve the issue,
but that does not seem to be the case.

This seems unrelated to powertop; `auto' seems to be the default setting
of /sys/bus/usb/devices/*/power/control, which is reset on reboot.  In
any case, setting it to `on' does not solve my suspend issue.

It's not a hardware issue, because earlier kernel versions work just
fine.

I tried debugging this further, but even on a minimal Guix system, I
cannot seem to work around the problem.

Any advice, anyone?

-- 
Mike Gerwitz