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No Analog Output

Dear Lazyweb,
I failed to figure out why I get no signal out of my DVI port with a DVI>DSUB dongle and a CRT attached when using Linux on my Macbook Pro. It works fine with a DVI cable, but on my CRT it’s blank. Xorg feels like everything is fine and I have a big framebuffer, my mouse is happily moving around the dead space. “Option” “WasteMoreTime” “off” didn’t seem to do the trick.

No surprise OSX works fine on that setup.

This entry was posted on Monday, February 11th, 2008 at 5:53 pm and is filed under lazyweb, openSUSE, x, xorg. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

6 Responses to “No Analog Output”

  1. Ted Gould Says:
    February 11th, 2008 at 6:36 pm

    Jimmac,

    With my Macbook Pro I foudn that I had to use the nvidia tools to get it working with the external monitor. Specifically firing up “nvidia-settings”. It wrote out the xorg.conf fie that I needed to make everything happy. This was with a projector, but I’m guessing your external display is similar.

    –Ted

  2. Tom Says:
    February 11th, 2008 at 6:57 pm

    If your using an nvidia card, you may need to use the “ConnectedMonitor” option (or similar, i foget exactly) to force it to be in “CRT” (analog) mode, as the driver is just assuming its digital. nvidia-settings probably lets you do it on the fly. If its an ati or intel card i have no idea sorry.

  3. Adam Williamson Says:
    February 11th, 2008 at 9:57 pm

    And if it happens to be Intel graphics (don’t know if any Macbooks use Intel adapters, but I’ve seen this exact bug lately), update to intel driver 2.2.0.90 or current git. 2.2.0 was a crap release and this was one of several bugs in it. Current git or 2.2.0.90 work fine.

  4. jimmac Says:
    February 12th, 2008 at 12:23 am

    Sadly my MBP has an ATI chip :/ The “MonitorLayout” suggested in the manpage doesn’t seem to do anything either.

  5. Phil Armstrong Says:
    February 12th, 2008 at 12:28 pm

    Does

    Option “MonitorLayout” “TMDS,CRT”

    in the xorg.conf device section make any difference?

    Alternatively, there are some Mac specific options for when the driver can’t detect the mapping of outputs reliably. Can’t remember what they’re called offhand though.

  6. jimmac Says:
    February 12th, 2008 at 5:31 pm

    Ok, so actually the trick seems to be the ForceMonitors option. Sax has generated

    Option “ForceMonitors” “auto,crt1″

    Changing that to Option “ForceMonitors” “lvds,crt” worked for me. Everything seems to mention crt1, but that doesn’t work for me. Strange.

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