|Summary:||Intel 2.2.1 driver refuses to start up if no display is connected|
|Product:||xorg||Reporter:||Simon Farnsworth <simon.farnsworth>|
|Component:||Driver/intel||Assignee:||Gordon Jin <gordon.jin>|
|Status:||RESOLVED DUPLICATE||QA Contact:||Xorg Project Team <xorg-team>|
|i915 platform:||i915 features:|
Description Simon Farnsworth 2008-03-18 08:38:20 UTC
Created attachment 15251 [details] X configuration The 2.2.1 release of the Intel driver refuses to start if no screen is connected, despite a X configuration file telling it to go ahead anyway. The configuration used is attached.
Comment 1 Simon Farnsworth 2008-03-18 08:39:06 UTC
Created attachment 15252 [details] Log of failing startup And the logfile Xorg generates when we start up without a display
Comment 2 Simon Farnsworth 2008-03-18 09:55:56 UTC
Found the cause, and a workaround for us: xf86ProbeOutputModes in Xorg's hw/xfree86/modes/xf86Crtc.c doesn't set up any modes for outputs that are definitely disconnected (output control function returns XF86OutputStatusDisconnected). i830_crt_detect in the driver's src/i830_crt.c returns XF86OutputStatusDisconnected if one of the believed reliable detection methods returns false. The interaction between the two ensures that there are no modes available for a disconnected output. In our situation, we can work around this by replacing XF86OutputStatusDisconnected with XF86OutputStatusUnknown in i830_crt_detect.