Arch Linux

storrgie

Member

Registered: 2016-06-03

Posts: 19

[Lenovo T470s] Display Poweroff sometimes becomes unresponsive

I've been lucky to have access to several T470s. I'm seeing this behaviour on several of them. I install the same each time following this abbreviated path.

The machines are fully functional, suspend resume just fine. However, when I leave the machine alone on the docking station for a period long enough for my lock screen to activate and display to turn off (3-5 minutes) then it seems almost entirely likely that when I return the machine will be on but will be unresponsive. My only option is to hard power off and begin the boot sequence again. This behaviour is pretty consistent, if I return to my laptop after stepping up from my desk for more than a half hour I am entirely surprised if a mouse wiggle or keypress will wake the displays, it seems about 95% of the time the displays are completely unresponsive.

Some context for my environment:

- updates consumed daily
- bios updates consumed as often as relased
- microcode updates consumed as often as released
- gnome-shell on wayland
- Lenovo ultra dock with two displayport attached displays
- bios configured for 'balanced', as opposed to 'maximum power', for fear this could be triggered by a thermal issue
- relatively cool environment (66F-72F at all times)

I saw a discussion here which indicated that there was a new default for intel_iommu, but another user reported here that the default for intel_iommu was reverted back to its original state for 4.13.5-1 and I've seen this manifest several times since consuming the 4.13.5-1 update. There is a bug report here for arch and a report for the kernel.

I wanted to register a note that this is occurring on this particular system, as well as provide my own description of the situation. It very well could be related to the intel_iommu settings. and I'm going to try intel_iommu=off for the next couple days and report back. I'd just like someone to chime in if I'm thinking this intel_iommu thing is a panacea for what might be another issue with my system.

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 21,665

Re: [Lenovo T470s] Display Poweroff sometimes becomes unresponsive

Apart from your observations we have relatively little to go by. You should post a journal output from after a "freeze" (does it really freeze? Can you SSH in?) If you have to reboot, you can get the journal from the last boot with the -b parameter, like

journalctl -b-1

for the previous boot.

storrgie

Member

Registered: 2016-06-03

Posts: 19

Re: [Lenovo T470s] Display Poweroff sometimes becomes unresponsive

I'll start an sshd so that I can test to see if networking is present when displays become unresponsive.

I've examined previous boots for many weeks now and there isn't a consistent set of messages that can be time correlated to the event. I will respond here with a dump of the journal when this phenomena occurs again.

It's a bit like Schrödinger's Thinkpad right now because I've been unable to introduce this instability in a reproducible fashion. By checking to see if it has gone into the unresponsive state I wake up all of the displays again and that seems to keep it "alive" longer.

Last edited by storrgie (2017-10-16 11:11:23)