{"id":302,"date":"2009-01-01T18:09:24","date_gmt":"2009-01-02T01:09:24","guid":{"rendered":"http:\/\/www.graphics-muse.org\/wp\/?p=302"},"modified":"2009-01-07T11:31:40","modified_gmt":"2009-01-07T18:31:40","slug":"fedora-10-issues-with-intel-driver-and-multihead","status":"publish","type":"post","link":"https:\/\/www.graphics-muse.org\/wp\/?p=302","title":{"rendered":"Fedora 10 issues with intel driver and multihead"},"content":{"rendered":"

Over the holidays I upgraded my laptop to Fedora 10 (previously I had only upgraded my MythTV server).\u00a0 The upgrade went fairly smoothly following the information from my previous post on upgrading a MythTV server to F10<\/a>.\u00a0 However, my laptop supports dual monitors.\u00a0 Of course, that didn’t work out of the box.<\/p>\n

The laptop, my trusty Acer Aspire 1691WLMi with Intel i915GM graphics, offers output to the LCD, an external VGA port and a TV out.\u00a0 The latter I use when I use the laptop as a MythTV frontend and plug into the big screen TV. The VGA port I use when giving talks at user groups or presentations at work.<\/p>\n

Note:\u00a0 Use of the laptop as a MythTV frontend is no longer much of an issue now that the big screen TV died right before xmas.\u00a0 *sigh* However, I still use the laptop as a frontend while working, with an external monitor used for normal use and the LCD as my TV screen.
\n<\/em><\/span><\/p>\n

With Fedora 9 and prior the setup for using multihead with the intel driver required making changes to the xorg.conf file.\u00a0 With F10 there is no xorg.conf file – the configuration is automatically determined by the driver.\u00a0 This works fine for singlehead configuration (just the LCD, for example) but fails with the external monitor.\u00a0 The reason it fails is that the default virtual display size is too small to place the monitors side by side (or even top and bottom) in the video memory space.\u00a0 What is required is a Virtual entry in the Screen Display section of the xorg.conf.\u00a0 This will increase the default size to something large enough to fit both monitors.<\/p>\n

And here is where things broke with F10.\u00a0 If you specify the Virtual entry in that section of the xorg.conf file the gdm greeter<\/strong> locks up the system before you can login and use the new configuration.\u00a0 This is a known problem (see the Red Hat report<\/a> and the associated freedesktop.org bug reports on the intel driver<\/a> and GEM<\/a>) that may be fixed but the latest F10 updates (as of 2009-01-01) apparently do not include the fix.<\/p>\n

The workaround is to disable acceleration in the driver by adding the noaccel<\/strong><\/em> option (see my F10 xorg.conf<\/a> file for an example).\u00a0 Disabling acceleration isn’t a problem for me so far, especially since the older F9 configuration specified that anything over 2048×2048 (which is what I need for my dual monitors) would disable 3D support anyway.\u00a0 However it does affect the quality of video playback under the MythTV frontend.\u00a0 The best configuration I can get from this is to go under Setup->TV Settings->Playback and change the following:<\/p>\n