I installed Ubuntu gnome flavor on my laptop machine Dell inspiron N4030, the desired resolution for this device is 1366x766, but it was not found in the list of resolutions for display manager, I made my search, and found that it's possible to add the the desired resolution manually using the following commands
sudo xrandr --newmode "1368x768_60.00" 85.25 1368 1440 1576 1784 768 771 781 798 -hsync +vsync
sudo xrandr --addmode default 1368x768_60.00
and when it comes to execute the command to set the desired resolution I get as folowwing
xrandr --output default --mode "1368x768_60.00"
I get the output as :
xrandr: Failed to get size of gamma for output default
Configure crtc 0 failed
I checked the log for more information and I found this:
(gnome-settings-daemon:1331): color-plugin-WARNING **: unable to get
EDID for xrandr-default: unable to get EDID for output
and here are the details about my driver
sudo lshw -c video *-display UNCLAIMED
description: VGA compatible controller
product: Park [Mobility Radeon HD 5430]
vendor: Advanced Micro Devices, Inc. [AMD/ATI]
physical id: 0
bus info: pci@0000:01:00.0
version: 00
width: 64 bits
clock: 33MHz
capabilities: pm pciexpress msi vga_controller bus_master cap_list
configuration: latency=0
resources: memory:c0000000-cfffffff memory:fbe20000-fbe3ffff ioport:e000(size=256) memory:c0000-dffff
