Red Hat Bugzilla – Bug 470445
Dual-monitor via sisusb fails to initialize on OLPC XO hardware
Last modified: 2018-04-11 06:22:51 EDT
Description of problem:
If a USB VGA adapter is used, the XO laptop can drive an external monitor. This can be done by modifying xorg.conf and works fine if only the external monitor is used. However, if xorg.conf is set up to drive both the external monitor and the built-in Geode-based internal LCD display, X fails to start. Instead, it repeatedly tries to initialize the graphics mode on both screens, then falls back to text mode, and repeats the process. This cycle can be interrupted by unplugging the USB VGA adapter.
This testing was done with a UVA200 sisusb adapter: <http://www.futureshop.ca/catalog/proddetail.asp?logon=&langid=EN&sku_id=0665000FS10091172&catid=256>
Steps to Reproduce:
1. Replace xorg.conf with the attached file
2. Plug in the USB VGA adaptor
3. Reset X (Ctrl-Alt-Backspace)
Both screens repeatedly flicker as if they are switching graphics modes.
X should start using both screens.
The attached xorg.conf works fine if either of the Screen settings in the ServerLayout are removed.
Created attachment 322822 [details]
xorg.conf attempting to use both screens
Created attachment 322825 [details]
log file produced with failed initialization
Are you able to do some magic with xrandr(1) or gnome-display-properties? If yes, then if you read http://udrepper.livejournal.com/20187.html can you make it work following his steps?
I'm not quite sure how to adapt the steps given at http://udrepper.livejournal.com/20187.html to this situation, since there are two separate Devices being used (the AMD Geode and the sisusb). However, I wasn't very familiar with xrandr (I'd previously used Xinerama for this sort of thing), so I did some digging around and found this page http://wiki.debian.org/XStrikeForce/HowToRandR12 which notes that:
"RandR 1.2 does not support multiple boards yet (it's planned for RandR 1.3). It means that any RandR 1.2 aware driver will crash the server if you have 2 boards. Even one board with a RandR 1.2 driver and another board with a classic driver does not work. It just crashes the X server."
That sounds like exactly what I am seeing here, so there may not be a fix for this....
Adam, is this correct? Is there any hope for this bug or is this WONTFIX (anytime soon, that is)?
This bug appears to have been reported against 'rawhide' during the Fedora 10 development cycle.
Changing version to '10'.
More information and reason for this action is here:
This is the same as bug 510059 which is part of Fedora 'fit and finish'
*** This bug has been marked as a duplicate of bug 510059 ***