Red Hat Bugzilla – Bug 138347
Second monitor not turned on after reboot in dual-head config
Last modified: 2007-11-30 17:07:04 EST
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Description of problem:
I use a Matrox G550 AGP card and two Sony E500 monitors in a dual-head
configuration for extra screen real estate for XFree86. The
configuration worked fine after I edited my XF86Config file, but when
I rebooted the box, the second monitor failed to turn on (it remained
in power save mode). In my case the second monitor is the one
connected to the DVI port on the card. This happens every time I
reboot the box without fail. The only workaround I know of is to stop
X (telinit 3), remove the XF86Config file (mv /etc/X11/XF86Config
/tmp), run redhat-config-xfree86, which turns on the second monitor in
mirror mode, kill redhat-config-xfree86, restore the XF86Config file
(mv /tmp/XF86Config /etc/X11/), and restart X (telinit 5).
Version-Release number of selected component (if applicable):
Steps to Reproduce:
2.If you don't have X configured to start on bootup, go to runlevel 5
(telinit 5) or simply start X (startx).
Actual Results: Second monitor remains in power save/no signal mode.
Expected Results: Second monitor should power up and show second half
of the desktop.
Created attachment 106281 [details]
My /etc/X11/XF86Config file for dual heads on a Matrox G550.
Sounds similar to Bug 126820, though of course Fedora is using x.org
instead of XFree86.
Created attachment 106282 [details]
/var/log/XFree86.0.log after bootup (second monitor not on)
Created attachment 106283 [details]
/var/log/XFree86.log after running redhat-config-xfree86, killing it, restoring config, and restarting X again.
The open source "mga" driver does not work properly with DVI hardware
as the support is experimental only, and was never completed in XFree86
or X.org. Matrox started shipping their drivers proprietary after this,
and has never contributed fixes for DVI back to the X projects. As such,
DVI panels are basically unsupported on mga hardware at this point.
The "mga" manpage has links to Matrox's website, where you can download
Matrox's proprietary driver and hallib module which some people have
reported good results. While Red Hat does not support 3rd party drivers,
you may find they work for your hardware better than the open source
one supplied with the OS. Hopefully this unsupported workaround will
be a useable solution. Alternatively, you might try replacing the
card with a card that has better open source driver support. While I
can't recommend a specific card, you might be able to find suggestions
on one of the XFree86 or X.Org mailing lists. Alternatively you can
contact Red Hat Global Support Services at http://www.redhat.com/support
or at 1-888-RED-HAT1 which is our official support mechanism for
Red Hat Enterprise Linux. Hope this helps.
Setting status to "WONTFIX", as unfortunately, Matrox has not supplied
hardware documentation for the G550 hardware to open source developers,
so DVI will probably never be supported in the open source 'mga'
driver included with XFree86 (in RHEL3) and X.Org X11 (in RHEL4).