Bug 32988

Summary: xorg sets wrong resolution when 2 monitors are connected
Product: xorg Reporter: benderamp <benderamp>
Component: Server/GeneralAssignee: Xorg Project Team <xorg-team>
Status: RESOLVED NOTABUG QA Contact: Xorg Project Team <xorg-team>
Severity: normal    
Priority: medium    
Version: git   
Hardware: Other   
OS: All   
Whiteboard:
i915 platform: i915 features:
Attachments:
Description Flags
Xorg.log
none
dmesg output
none
xorg.conf.d dir archive with all config files inside none

Description benderamp 2011-01-11 02:43:51 UTC 
I have xorg 7.6 from opensuse factory, ATI r600 card with opensource driver. 2 monitors connected with DVI: 

- DVI-0 - monitor with 1280x1024 preferred resolution connected with DVI2DVI cable
- DVI-1 - TV with 1028x720 preferred resolution connected with DVI2HDMI cable

If both cables are connected when system boots, I receive 640x480 in kdm and also on the desktop (both on dvi-0 monitor and on dvi-1 tv). I can fix this in kde system config "display and monitor"/"size and orientation" module even without restarting X, but when I reboot comp, the resolution is again reset to 640x480.

If I remove DVI-1 cable (with TV) and resboot, I receive correct 1280x1024 on DVI-0 monitor both in KDM and on the desktop automatically without making any additional configuration.
Comment 1 Alex Deucher 2011-01-11 08:25:52 UTC 
Please attach your xorg log, config, and dmesg output.
Comment 2 benderamp 2011-01-11 10:15:21 UTC 
Created attachment 41883 [details] [review]
Xorg.log
Comment 3 benderamp 2011-01-11 10:16:32 UTC 
Created attachment 41884 [details]
dmesg output
Comment 4 benderamp 2011-01-11 10:20:44 UTC 
Created attachment 41885 [details]
xorg.conf.d dir archive with all config files inside
Comment 5 Alex Deucher 2011-01-11 10:43:02 UTC 
This is an xserver issue rather than a driver issue:
[    29.088] (II) RADEON(1): Using fuzzy aspect match for initial modes
[    29.088] (II) RADEON(1): Output DVI-0 using initial mode 640x480
[    29.088] (II) RADEON(1): Output DVI-1 using initial mode 640x480

The xserver comes up by default in clone mode and it tries to match all attached heads to the largest common mode supported by both.  In your case, that ends up being 640x480.  Most desktop managers will remember your xrandr settings if you use their tools to configure your monitors.  You might try the kde randr applet.  Alternatively, you can manually configure the preferred modes for your monitors in your xorg.conf.  See section III of this page:
http://wiki.debian.org/XStrikeForce/HowToRandR12
Comment 6 Jerome Glisse 2011-03-07 12:08:16 UTC 
User configuration issue

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