Can't force resolution on my LCD TV

[vikingpl]

I'm working on Radeon Gigabyte 6850 OC. My default monitor resolution is 1600x900 and that's fine. My second display is Philips Tv 7404H. With fglrx (or Windows) driver supported resolutions are

1920x1080    1776x1000    1680x1050    1400x1050     1600x900    1360x1024    1280x1024    1440x900    1280x960   1280x768   1280x720   1024x768   1152x648   800x600   720x480   640x480

but on radeon driver

1920x1080      60.0 +   50.0     24.0  
   1280x1024      60.0  
   1360x768       59.8  
   1024x768       60.0* 
   800x600        60.3  
   640x480        60.0

I can force for example 1280x720 with cvt tool and xrandr --newmode but I have no idea how to add 1600x900@50 (/ 25) and clone my primary display 1:1. I got unsupported video format message on my TV. Any ideas?
Thank You.

OpenSuse 11.4, kernel-desktop-2.6.39.2-35.1.x86_64

[darkbasic]

~$ gtf 1600 900 50

# 1600x900 @ 50.00 Hz (GTF) hsync: 46.30 kHz; pclk: 97.04 MHz
Modeline "1600x900_50.00" 97.04 1600 1680 1848 2096 900 901 904 926 -HSync +Vsync

xrandr --newmode "1600x900_50.00" 97.04 1600 1680 1848 2096 900 901 904 926 -HSync +Vsync

xrandr --addmode DVI-0 1600x900_50.00

xrandr --output DVI-0 --mode 1600x900_50.00

[vikingpl]

Yes, I tried this but I got "Unsupported video format".

[agd5f]

You probably need reduced blanking timings. Try cvt rather than gtf. Also, IIRC, the drm edid code does not parse all the hdmi extension blocks which is generally where the common consumer device modes live. It should be possible to port the edid hdmi extension block parsing from X to the kernel.

[vikingpl]

I tried both: cvt and gtf. I can't use -r mode because my tv has at max 1600x900@50Hz and for reduced blanking multiply of 60 is required. Also tried Option "ExactModeTimingsDVI" "false" (I have DVI->HDMI cable but modes are not detected on hdmi->hdmi as well).

[agd5f]

You can also just copy the modeline from fglrx or your xorg log.

[vikingpl]

Just finished testing. Fglrx modes:

Modeline "1600x900_50.00"  148.50  1600 2448 2492 2640  900 1084 1089 1125 +hsync +vsync
  Modeline "1600x900_25.00"   74.25  1600 2448 2492 2640  900 1084 1089 1125 +hsync +vsync
  Modeline "1600x900_30.00"   74.18  1600 2008 2052 2200  900 1084 1089 1125 +hsync +vsync
  Modeline "1600x900_24.00"   74.18  1600 2558 2602 2750  900 1084 1089 1125 +hsync +vsync

But none of them works with radeon driver