William Shallum

Linux force 1920x1080 CVT-RB timings (for LG M227 TV Monitor)

Posted Dec 24 2011, 10:56 by William Shallum [updated Oct 2 2014, 08:14]

The TV monitor when fed through HDMI prefers TV mode (overscan) by default. It needs to be fed a 1920x1080 signal with CVT-RB timing to display 1:1 pixels.

The kernel parameter to use is (for linux framebuffer)

video=1920x1080RM@60

Note: this is for kernel 2.6.39-bpo.2 (from Debian backports). In newer versions it seems that the R and M should be switched: “1920x1080MR@60”. As always, use the source.

For X11, these xrandr invocations should help. TODO: put this in xorg.conf

xrandr --newmode "1920x1080R@60" 138.50 1920 1968 2000 2080 1080 1083 1088 1111 +hsync -vsync
xrandr --addmode HDMI4 "1920x1080R@60"
xrandr --output HDMI4 --mode "1920x1080R@60"

The timings can be obtained from the cvt utility:

cvt -r 1920 1080 60