ATI open-source driver and modelines

Question

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

Answer 1

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)