Bug 66211

Summary:	Thinkpad T440s with 2nd screen via dock freezes
Product:	Drivers	Reporter:	madevr.orange
Component:	Video(DRI - Intel)	Assignee:	intel-gfx-bugs (intel-gfx-bugs)
Status:	RESOLVED MOVED
Severity:	normal	CC:	intel-gfx-bugs, kepler-milden-nates-haves
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	3.12	Subsystem:
Regression:	No	Bisected commit-id:

Description madevr.orange 2013-11-30 09:04:34 UTC

Hi there.

There seems to be a problem with using a 2nd screen via dock on the Thinkpad T440s. I have the version with Intel HD4400 only, but users with additional dedicated graphics also report this (though Intel seems to be the cause).

Steps to reproduce:
1) Power off Thinkpad T440s, connect 2nd screen to dock, put Thinkpad into dock.
2) Boot Thinkpad: both screens stay black.

or

1) Power on Thinkpad, leave it on and connect 2nd screen to dock
2) Put Thinkpad into dock - the system freezes, 2nd screen shows no image.

In both cases the system can be unfrozen by undocking.

Connecting a 2nd screen directly to the Thinkpad works as intended.

Apparently more users start to experience this problem: https://bbs.archlinux.org/viewtopic.php?id=173134

I am completely new to reporting kernel bugs but am eager to help solving this problem. Let me know how I can help. ;)

Comment 1 kepler 2013-12-16 08:52:45 UTC

I can confirm this. Meanwhile, over at fdo, people seem to be working on the issue:

https://bugs.freedesktop.org/show_bug.cgi?id=71267

Comment 2 Jani Nikula 2014-01-23 08:31:50 UTC

(In reply to kepler from comment #1)
> I can confirm this. Meanwhile, over at fdo, people seem to be working on the
> issue:
> 
> https://bugs.freedesktop.org/show_bug.cgi?id=71267

Yeah, let's track this there. Please reopen if you think this is a different issue.