How can one change login screen resolution with propreitary graphic driver installed?

Question

I installed the latest AMD BETA driver from this site . The installation was perfect. But now I am not able to see my login screen(where you type your password, as you know). My monitor displays "OUT OF RANGE" when I am on my login screen . But I can type in my password and enter into my Desktop without any problem. Probably the login screen resolution is beyond the resolution of my monitor. If that is the case, then how can I change the resolution of the login screen alone? (BTW, my graphic card is ATI Radeon 5570 HD. I have DELL monitor with maximum resolution of 1366x768. Also I can view my desktop without problems.)

PS:- This question is very much similar to this question. But none of the solutions solve the problem in 14.04 which I am using. Note that the problem stated above was also present in Ubuntu 13.10.

Answer 1

After searching I found the answer in launchpad. This is an issue with xorg.conf file actually. One can generate the xorg.conf file by using the command

sudo aticonfig --initial

if one is having the AMD driver. Else one may try

sudo nvidia-xconfig

if one has nvidia graphic driver.

Then one needs to open the xorg.conf file by running the below command,

sudo gedit /etc/X11/xorg.conf

In the command above one can use one's favorite text editor instead of gedit. In the xorg.conf file one must edit the screen section which is this:

Section "Screen"
 Identifier "aticonfig-Screen[0]-0"
 Device "aticonfig-Device[0]-0"
 Monitor "aticonfig-Monitor[0]-0"
 DefaultDepth 24
 SubSection "Display"
  Viewport 0 0
  Depth 24
 EndSubSection
EndSection

To something like this:

Section "Screen"
 Identifier "aticonfig-Screen[0]-0"
 Device "aticonfig-Device[0]-0"
 Monitor "aticonfig-Monitor[0]-0"
 DefaultDepth 24
 SubSection "Display"
  Viewport 0 0
  Depth 24
  Modes "1366x768"
 EndSubSection
EndSection

One can give whichever resolution is compatible with one's monitor after Modes instead of 1366x768. This solves the problem. Credits to this answer here from launchpad.