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Problem with HD resolution (720p) when using fglrx.

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  • Problem with HD resolution (720p) when using fglrx.

    Hello I'm new here.

    I have a 15m HDMI-HDMI-cord (by Deltaco, claims to support 1080i) but I can't get the fglrx-driver to switch to 720p resolution (1280x720). I have to use aticonfig --force-monitor=tmds2i to even get a picture. The maximum resolution I get is 1024x768.

    My best guess is that fglrx does not get the EDID information an thus defaults to maximum 1024x768. This could be because of the cord, 15m is pushing it, I know.

    HOWEVER, here comes the kicker: when using the open source ati-driver everything works just fine! EDID information is received without problem. But this driver does not support accelerated OpenGL yet (I want to use Elisa for my HTPC). So my guess is that it's not because of the cord as I initially thought. I even bought a HDMI-DVI gender changer, but I would still not get any increased resolution/EDID-information.

    My last cord was a 10m DVI-HDMI type from Eagle. When I'm using this cord, the fglrx-driver works fine.

    Any ideas? Can I Force the fglrx-driver to always output a 720p-signal or force it to support a monitor even if the fglrx-driver does not detect it? I tried editing the xorg.conf in various ways without any luck. My current xorg.conf is a vanilla with an additional driver "fglrx" added.

    My Xorg.0.log output:

    Extremely grateful for any hints or tips. I tried posting this elsewhere with zero replies.

  • #2
    I believe there are some controls in CCC specifically for setting TV timings & outputs, although I haven't played with them myself. Have you experimented with those ?


    • #3
      Originally posted by bridgman View Post
      I believe there are some controls in CCC specifically for setting TV timings & outputs, although I haven't played with them myself. Have you experimented with those ?
      Thank you for your quick reply! To answer your question, no I haven't. I had the impression that TV output was specifically for s-video / composite output so haven't given them much attention.

      I will defiantly give this a try. I'm going away for a short skiing weekend so I won't be able to try it until I'm back on the 2:nd or 3:rd. I will report back when I have tried it.

      Happy New Year in the meantime!


      • #4
        Hello again,

        I tried locating the TV-options in CCC but could not find anything. It only lists default resolutions (320x200 - 1024x768). I tried using the option aticonfing --tv-geometry=1280x720 to force a specific resolution, but I only get segmentation fault printed to the console.

        I'm using the 8.12 driver and I actually get the same result using another computer when using aticonfig. I suspect that this might be a bug or a regression in the 8.12-driver.

        Anyhow, I'm back to square one. Fglrx don't recieve the correct EDID-info and therefore does not give me the correct resolutions.

        Does anybody know how to report bugs to the fglrx team? Do they have any public bugtracker?

        EDIT: Found this bug and this thread
        Problem exists since 2005 it seems. I guess I will buy an NVIDIA-card instead (I have an 780g motherboard right now) if I can"t get modelines to work.
        Last edited by Magnusart; 01-04-2009, 02:24 PM.


        • #5


          • #6
            Wow, I actually got it to work.

            The problem is still there but I have a workaround. It seems that the fglrx driver has problem with EDID (as stated previously) but it accepts modelines in the xorg.conf file. My second problem was that Catalyst 8.12 gives me segfaults when I use aticonfig, so I had to downgrade to an earlier driver.

            I used this modeline generated with the command "gft 1280 720 60" from the terminal: ModeLine "1280x720_60.00" 74.5 1280 1336 1472 1664 720 721 724 746 -hsync +vsync

            That did the trick, but at first I got the above resolution into a 1024x728 area on my screen (it was streched and masked, both at the same time). But by removing the fglrx driver (using /usr/share/ati/ and reinstalling fglrx 8.11, I was able to get the correct resolution right away.

            I hope this helps someone else as well. I spent considerable time trying to figure this out. Please ask for any clarifications.