xorg resolution

  • http://www.unixmen.com/ubuntu-12-10-and-amd-catalyst-problem-solved/
  • http://www.x.org/wiki/FAQVideoModes
  • http://grenage.com/xorg.html
  • https://wiki.ubuntu.com/X/Config/Resolution#Adding_undetected_resolutions
  • http://askubuntu.com/questions/94053/fails-to-get-size-of-gamma-error-when-trying-to-set-resolution
  • http://fluxbox-wiki.org/index.php?title=Cambiare_risoluzione
  • http://dreamlinuxforums.org/index.php?topic=6528.15
  • http://wiki.ubuntu-it.org/Hardware/Video/DoppioMonitor
  • http://wiki.ubuntu-it.org/Hardware/Video/DoppioMonitor/BigDesktop

hardware:

sudo lshw | grep display
 
glxinfo
 
lspci | grep VGA
lspci -nn | grep ATI
 
01:00.0 VGA compatible controller [0300]: Advanced Micro Devices [AMD] nee ATI RV635
 
[Mobility Radeon HD 3650] [1002:9591]
 
Monitor name: LP154WX4-TLC8  LGPhilipsLCD

monitor sending bad (or no) resolution information to the driver. The driver then restricts itself to common defaults (e.g. 640x480 or 800x600, or sometimes 1024x768). Sometimes a bad cable is at fault.

sudo get-edid

dice: DDC2 transfers

higher refresh rates (to avoid "flicker") were useful on CRTs because of the technology involved. The phosphors on the CRT would decay(lose brightness) if they weren't refreshed quickly enough and that could cause eyestrain. An LCD monitor doesn't work that way, basically it remains in state until changed.

Error

gedit /var/log/Xorg.0.log
 
(II) VESA(0): Not using mode "1280x1024" (no mode of this name)
No valid modes left. Trying less strict filter...

Drivers

VESA, ATI or Intel?:

sudo apt-get install xresprobe
sudo ddcprobe

ATI fglrx drivers

sudo apt-get purge nvidia*
sudo dpkg-reconfigure xserver-xorg
sudo aticonfig --help
radeontool --help
sudo apt-get install fglrx-updates
./amd-driver-installer-12.6-legacy-x86.x86_64.run
less /usr/share/ati/fglrx-install.log
 
sudo aticonfig --initial -f
sudo aticonfig --acpi-services=off

Configuration

calcola i parametri adatti alla risoluzione

cvt 1024 1080 61
 
# 1024x1080 60.94 Hz (CVT) hsync: 68.31 kHz; pclk: 94.00 MHz
Modeline "1024x1080_61.00"   94.00  1024 1096 1200 1376  1080 1083 1093 1121 -hsync +vsync
 
xrandr --newmode 1024_1080  94.00  1024 1096 1200 1376  1080 1083 1093 1121 -hsync +vsync
xrandr --addmode 1024_1080
xrandr --output default --mode 1024_1080
error:
xrandr: Failed to get size of gamma for output default
xrandr -s 800x600 -r 61
xrandr -s 1024x768 -r 61

xorg.conf: There should be none;if there is one,it should not be empty.

/etc/X11/xorg.conf
sudo service gdm stop
sudo Xorg -configure
sudo service gdm start
sudo dpkg-reconfigure xserver-xorg
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 "1280x1024"  "1024x768"   "640x480"
    EndSubSection
       SubSection "Display"
               Depth           16
               Modes           "1600x1200" "1280x1024" "1024x768" "800x600" "640x480"
       EndSubSection
       SubSection "Display"
               Depth           24
               Modes           "1600x1200" "1280x1024" "1024x768" "800x600" "640x480"
       EndSubSection
EndSection
Section "Monitor"
   Identifier   "LGPhilipsLCD LP154WX4-TLC8"
   Option      "DPMS"
   HorizSync   30-81
   VertRefresh   56-76
EndSection
 
Section "Screen"
   Identifier   "Default Screen"
   Device      "Intel X4500"
   Monitor      "LGPhilipsLCD LP154WX4-TLC8"
   DefaultDepth   24
   SubSection "Display"
      Modes      "1280x800"
   EndSubSection
EndSection
locate MonitorsDB