Bug 72754 - Dual head: screen(s) do not turn back on after power save
Summary: Dual head: screen(s) do not turn back on after power save
Status: CLOSED WORKSFORME
Alias: None
Product: DRI
Classification: Unclassified
Component: DRM/Intel (show other bugs)
Version: unspecified
Hardware: x86-64 (AMD64) Linux (All)
: medium normal
Assignee: Intel GFX Bugs mailing list
QA Contact: Intel GFX Bugs mailing list
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2013-12-16 10:39 UTC by Tom Francart
Modified: 2017-07-24 22:56 UTC (History)
1 user (show)

See Also:
i915 platform:
i915 features:

Attachments
Xorg log file (53.80 KB, text/plain)
2013-12-16 10:39 UTC, Tom Francart 		no flags Details
Xrandr --verbose output (18.14 KB, text/plain)
2013-12-16 10:41 UTC, Tom Francart 		no flags Details
intel_reg_dumper output (14.49 KB, text/plain)
2013-12-16 10:42 UTC, Tom Francart 		no flags Details
View All

Description Tom Francart 2013-12-16 10:39:40 UTC 
Created attachment 90831 [details]
Xorg log file

Chipset: Intel(R) Ivybridge Mobile (GT2)
Driver: i965
Architecture: x86_64
libdrm version: 2.4.43-0ubuntu
Distro: Ubuntu quantal, kernel 3.5.0-44-generic
Machine: Dell Latitude E6230

I have a dual-head setup. When my monitors go into powersave mode (DPMS) and thereafter powersave is disabled, randomly one or both do not turn back on (no backlight, no image). It can be fixed by switching to console and back one or more times (Ctrl+Alt+F1), or by running xrandr and doing a mode switch (one or more times). 
I want to emphasise the random nature: it does not always happen, and I have to repeat the solution one or more times for the problem to disappear. The monitor that does not turn on is also random (either one or both).

The setup is a Dell Latitude E6230 Laptop on a Dell Docking station. Both external monitors are connected to the docking station using DVI connectors. The laptop's display is turned off. This configuration is achieved using 

xrandr --output DP3 --off --output DP2 --off --output DP1 --off --output HDMI3 --mode 1920x1080 --pos 1080x40 --rotate normal --primary --output HDMI2 --mode 1920x1080 --pos 0x0 --rotate left --left-of HDMI3 --output HDMI1 --off --output LVDS1 --off --output VGA1 --off
Comment 1 Tom Francart 2013-12-16 10:41:19 UTC 
Created attachment 90832 [details]
Xrandr --verbose output
Comment 2 Tom Francart 2013-12-16 10:42:48 UTC 
Created attachment 90833 [details]
intel_reg_dumper output

This was obtained with one of the screens erroneously turned off
Comment 3 Chris Wilson 2013-12-16 10:58:33 UTC 
3.5 is too old for the purposes of an upstream bug report, especially in an area as active as modesetting.
Comment 4 Chris Wilson 2013-12-16 11:05:39 UTC 
Also note that SNA is more robust in this area as well.
Comment 5 Tom Francart 2014-01-02 14:10:04 UTC 
The problem was solved after upgrade to kernel 3.11.0 (Ubuntu saucy).
Thanks for the tip.
Comment 6 Chris Wilson 2014-01-02 15:06:54 UTC 
Let's hope it was indeed truly fixed...

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