Arch Linux

elahav

Member

From: Ottawa, ON

Registered: 2005-04-18

Posts: 90

ATI open-source driver and modelines

Since the 8.3x versions of fglrx do not work with custom modelines, I have tried to switch to the open-source driver. However, I still seem to have a problem with modelines. Here is the relevant section in my xorg.conf file:

Section "Monitor"
        Identifier   "Monitor0"
        VendorName   "Monitor Vendor"
        ModelName    "LCD Panel 1280x768"
        HorizSync    30-82
        VertRefresh  40-70
        Option      "dpms"
        # 1280x768 @ 60.00 Hz (GTF) hsync: 47.70 kHz; pclk: 80.14 MHz
        Modeline "1280x768_60"  80.14  1280 1344 1480 1680  768 769 772 795  -HSync +Vsync
EndSection

Here is what I get when I start X (excerpt from Xorg.0.log):

(--) RADEON(0): Virtual size is 1280x768 (pitch 1280)
(**) RADEON(0): *Mode "1280x768_60": 68.9 MHz (scaled from 0.0 MHz), 49.0 kHz, 6
0.0 Hz
(II) RADEON(0): Modeline "1280x768_60"   68.93  1280 1296 1320 1408  768 771 777
 816

I don't understand why the driver changes the modeline parameters. Any ideas?

On a related issue - anyone got the 8.2x fglrx drivers working with the latest kernel and X? Everything was fine with my setup before I upgraded to 2.6.20 and 7.2.0.

Elad

skale

Member

From: Atlanta, GA

Registered: 2006-08-04

Posts: 146

Re: ATI open-source driver and modelines

What's changed?  If the monitor works fine (without bad resolution or the streaks characteristic of ugly refresh rates), I'd leave it alone.  The driver probably has its own ideas about modes.  Of course, that's just me.

This stuff might concern you, from the radeon man page.

Option "DDCMode" "boolean"
    Force to use the modes queried from the connected monitor.
    The default is off. 
Option "MonitorLayout" "string"

    This option is used to overwrite the detected monitor types. This is only required when driver makes a false detection. The possible monitor types are:
    NONE -- Not connected
    CRT -- Analog CRT monitor
    TMDS -- Desktop flat panel
    LVDS -- Lapto flat panel
    This option can be used in following format:
    Option "MonitorLayout" "[type on primary], [type on secondary]"
    For example, Option "MonitorLayout" "CRT, TMDS"

    Primary/Secondary head for dual-head cards:
    (when only one port is used, it will be treated as the primary regardless)
    Primary head:
    DVI port on DVI+VGA cards
    LCD output on laptops
    Internal TMDS prot on DVI+DVI cards
    Secondary head:
    VGA port on DVI+VGA cards
    VGA port on laptops
    External TMDS port on DVI+DVI cards

    The default value is undefined.

Last edited by skale (2007-03-13 00:56:19)