Bug 582525 - RFE: Detect powered off display correctly
Summary: RFE: Detect powered off display correctly
Keywords:
Status: CLOSED CANTFIX
Alias: None
Product: Fedora
Classification: Fedora
Component: xorg-x11-drv-intel
Version: 13
Hardware: All
OS: Linux
low
medium
Target Milestone: ---
Assignee: Adam Jackson
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2010-04-15 09:06 UTC by Kamil Páral
Modified: 2010-10-01 15:02 UTC (History)
4 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed: 2010-10-01 15:02:33 UTC
Type: ---
Embargoed:


Attachments (Terms of Use)
logs (470.00 KB, application/x-tar)
2010-04-15 09:06 UTC, Kamil Páral
no flags Details

Description Kamil Páral 2010-04-15 09:06:06 UTC
Created attachment 406712 [details]
logs

Description of problem:
I have laptop with external display connected through docking station. When I turn off the external display (even when plugging it out of electrical socket), it is still detected as connected by xrandr. When I boot my laptop with external display powered off, I don't see the login screen - the GDM uses spanned desktop and displays the login window exactly on the powered off external display - so I don't see it, I just see plain blue space of the laptop display.

The only way how to make xrandr aware that the external display is powered off is to disconnect DVI cable from the docking station. Then it correctly recognizes that the external display has been disconnected.

Version-Release number of selected component (if applicable):
Fedora 13
kernel-2.6.33.2-43.fc13.x86_64
mesa-dri-drivers-7.8.1-1.fc13.x86_64
mesa-libGL-7.8.1-1.fc13.x86_64
mesa-libGLU-7.8.1-1.fc13.x86_64
xorg-x11-drv-intel-2.10.0-4.fc13.x86_64
xorg-x11-server-utils-7.4-16.fc13.x86_64
xorg-x11-server-Xorg-1.8.0-4.fc13.x86_64
Smolt: http://www.smolts.org/client/show/pub_f5cefaa5-cad6-4d74-bb97-7263951ac836

How reproducible:
always

Steps to Reproduce:
1. Power off laptop in docking station.
2. Power off external display.
3. Boot laptop.

Actual results:
The external display is not recognized as disconnected when powered off.

Expected results:
The external display is recognized as disconnected when powered off.

Comment 1 Kamil Páral 2010-04-15 09:08:24 UTC
Oh and this bug was reported when doing Intel Test Day:
https://fedoraproject.org/wiki/Test_Day:2010-04-15_Intel
trying this test case:
https://fedoraproject.org/wiki/QA:Testcase_intelvideo_multihead

Comment 2 Adam Williamson 2010-04-16 18:20:56 UTC
A new version of the Intel driver, xorg-x11-drv-intel-2.11.0-1.fc13, has just been added: https://admin.fedoraproject.org/updates/xorg-x11-drv-intel-2.11.0-1.fc13 . Can you please test with this version and see if the bug is reproducible? If you have an installed Fedora 13, you can download and install the driver from the Koji link. If you are testing with live images, the nightly live images from 2010-04-17 (or possibly 2010-04-18) onwards should include this version: http://alt.fedoraproject.org/pub/alt/nightly-composes/desktop/ . This comment is being added to all open Fedora 13 intel bugs, please ignore if it does not make sense in the context of your bug.

Comment 3 Kamil Páral 2010-04-21 15:47:05 UTC
No, xorg-x11-drv-intel-2.11.0-1.fc13 does not fix the problem.

Comment 4 Adam Jackson 2010-04-22 19:58:18 UTC
That's not wrong though.  We don't have any way of knowing whether an external monitor is powered (well, we could, but we don't implement any .  In fact, the DDC spec requires that monitors respond to EDID requests even when powered off, and the DVI connector supplies trickle power to make this work.

Comment 5 Adam Jackson 2010-04-22 19:58:53 UTC
Excuse me.  "We don't implement any of DDC/CI", and even then I'm only kind of sure it has that feature.

Comment 6 Kamil Páral 2010-04-23 08:23:31 UTC
I have absolutely no knowledge in this area. But you say it is possible to detect that, but it's just not implemented. So why this bug was closed instead of changing it to RFE?

When the default is spanned desktop, it's quite vital not to stretch the desktop to a powered off display. Especially when to login screen appears on the powered off display.

Comment 7 Kamil Páral 2010-05-11 10:45:11 UTC
According to Karel Volný's comment [1] reopening as RFE.

[1] http://lists.fedoraproject.org/pipermail/test/2010-May/090854.html

Adam, I will be glad if you can provide additional comments.

Comment 8 Adam Jackson 2010-05-12 13:56:14 UTC
So I re-read the CI spec for this.  CI does define another path to get at DPMS _controls_.  It's an optional monitor feature, so some displays may not implement it.  But, it does not really specify any way of getting absolute power state.  There might be a way to infer it from various bits of behaviour when you try to power it on, but that's likely to vary wildly between display controller chips.

At any rate, all of this is blocked on having CI support in the kernel at all.  So I mean, leave the bug open if it makes you feel better.


Note You need to log in before you can comment on or make changes to this bug.