Bug 15526

Summary: wrong initial mode selected - black screen
Product: xorg Reporter: Tormod Volden <bugzi11.fdo.tormod>
Component: Driver/RadeonAssignee: xf86-video-ati maintainers <xorg-driver-ati>
Status: RESOLVED FIXED QA Contact: Xorg Project Team <xorg-team>
Severity: normal    
Priority: medium    
Version: unspecified   
Hardware: Other   
OS: All   
URL: https://bugs.launchpad.net/bugs/214105
Whiteboard:
i915 platform: i915 features:
Attachments:
Description Flags
Xorg.0.log with ModeDebug, BusType PCI and DRI off
none
ddcprobe output none

Description Tormod Volden 2008-04-15 15:26:57 UTC 
Created attachment 15942 [details]
Xorg.0.log with ModeDebug, BusType PCI and DRI off  

Reported in Ubuntu Hardy using -ati driver from git 2008-04-04 and xorg-server 2:1.4.1~git20080131-1ubuntu6, https://bugs.launchpad.net/bugs/214105

At start-up an initial mode of 1440x900 is selected, which makes the monitor go black. ddcprobe does not list this resolution, but it appears in the "probed modes".

ATI Radeon 9250 5960 (AGP). (DRI was turned off in the attached log, since the AGP  speed mismatch would freeze the computer.)
Comment 1 Tormod Volden 2008-04-15 15:28:11 UTC 
Created attachment 15943 [details]
ddcprobe output
Comment 2 Dave Airlie 2008-04-15 16:46:25 UTC 
if your xorg.conf has a monitor section please remove it..
Comment 3 Tormod Volden 2008-04-16 14:25:42 UTC 
Thanks, removing the Monitor section did the trick. How does it work? Is another way of selection done if monitor frequencies are specified? Is the ddc probing then ignored?
Comment 4 Dave Airlie 2008-04-16 16:45:07 UTC 
If there is no monitor section we just believe the monitor, if there is a monitor section we check the modes against the constraints of the monitor section, which means the timings in the monitor section constrain the modes wrongly.

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