xrandr --output HDMI-0 --set underscan off
but I don't see that as a good long-term solution. I believe that forcing underscan on everybody is a bad design decision and I firmly reject their tyrannic Underscan World Order.
If you're using fglrx, then you need to turn KMS off in the first place, don't you? In which case none of this is affecting you AFAIK
Hmm. Thanks for the reply.
I recently move backward from r600g+2.6.37-rc6+UNDERSCAN_OFF to fglrx+2.6.35. I got underscan problem with the later config and I don't know how to disable it. the xrandr solution is not possible in my case since I don't use X.
if you don't use X, why do you need fglrx?
using xrandr does not end your X session. You can add the line xrandr --underscan=off to your .xinitrc
Man, fglrx is buggy (tearing and random TV signal disconnect). I switched back to r600g and felt much better. The higher speed that fglrx provides isn't worth the setup hassle and the bugs.