Bug 26853

Summary: resolution drops to VGA when external monitor is connected while X starts
Product: xorg Reporter: Rolf Leggewie <bugs.freedesktop.org>
Component: Driver/intelAssignee: Jesse Barnes <jbarnes>
Status: RESOLVED NOTOURBUG QA Contact: Xorg Project Team <xorg-team>
Severity: normal    
Priority: medium    
Version: 7.4 (2008.09)   
Hardware: Other   
OS: All   
URL: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/531164
Whiteboard:
i915 platform: i915 features:
Attachments:
Description Flags
dmesg log with drm.debug=0x04 none

Description Rolf Leggewie 2010-03-02 23:38:58 UTC
ASUS 1001p netbook with 1024x600 internal resolution. When I connect an external monitor (resolution 1680x1050) while X starts the resolution drops to VGA. In that case (IIRC), the display applet or grandr will later not be able to rectify the situation. If I start X on the internal display only, connect the external monitor and then extend the viewable area with grandr or the display applet everything works fine.

much more information and logs available at https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/531164
Comment 1 ykzhao 2010-03-15 06:58:46 UTC
Will you please add the boot option of "drm.debug=0x04" and attach the output of dmesg?

Thanks.
Comment 2 Rolf Leggewie 2010-05-05 01:52:15 UTC
It's well possible I may not be able to test this before beginning of June.  Please bear with me.
Comment 3 Rolf Leggewie 2010-05-05 01:52:37 UTC
Sorry, beginning of July, even.
Comment 4 Jesse Barnes 2010-07-15 11:01:01 UTC
Wow, this is an old one.  Assuming it's fixed though.

X will configure the outputs differently depending on what's connected at startup, so this could be expected behavior.  You may have to unclone or unmirror the displays after starting up this way before you can change things.
Comment 5 Rolf Leggewie 2010-11-29 14:58:59 UTC
Created attachment 40650 [details]
dmesg log with drm.debug=0x04

(In reply to comment #4)
> Wow, this is an old one.  Assuming it's fixed though.

Old?  It's only been a few months old.  I apologize for the delay beyond the previously envisioned month of July.  I travel a lot and for extended periods of time and I can only test this at home.

Today, I booted with the latest Ubuntu mainline kernel (2.6.36-999-generic) and the issue is still present, albeit differently and to a much less severe degree.  The gdm login on my netbook will not be 1024*600 but 800*600.  Once I'm logged in to X, the resolution on the internal and external display is at it should be.

I attach the requested log.
Comment 6 Chris Wilson 2010-12-31 00:08:27 UTC
The kernel is behaving correctly; the fbcon is expected to be complete on all attached displays (its primary design role is for kernel panics). Your gui display applet is at fault here, convince yourself by using xrandr from the commandline instead.

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