Question

10

How to detect and configure an output with xrandr?

rated 0 times [ 10] [ 0] / answers: 1 / hits: 438697 / 3 Years ago, wed, august 25, 2021, 7:50:09

I have a DELL U2410 monitor connected to a Compaq 100B desktop equipped with an integrated AMD/ATI graphics card (AMD E-350). The installed O/S is Ubuntu 10.04 LTS.

The computer is connected to the monitor via the DVI connection.

The problem is that I cannot set the desktop resolution to the native 1920x1200. The maximum allowed resolution is 1600x1200.

Doing some research I found about the xrandr utility. Unfortunately, when trying to use it I cannot configure it to the required resolution. First, it does not report the output name (which supposed to be DVI-0), saying default instead. Without it I cannot use the --fb option.

The EDID utility seems to identify the monitor well. Here's the output from get-edid:

    # EDID version 1 revision 3

Section "Monitor"

    # Block type: 2:0 3:ff

    # Block type: 2:0 3:fc

    Identifier "DELL U2410"

    VendorName "DEL"

    ModelName "DELL U2410"

    # Block type: 2:0 3:ff

    # Block type: 2:0 3:fc

    # Block type: 2:0 3:fd

    HorizSync 30-81

    VertRefresh 56-76

    # Max dot clock (video bandwidth) 170 MHz

    # DPMS capabilities: Active off:yes  Suspend:yes  Standby:yes



    Mode    "1920x1200" # vfreq 59.950Hz, hfreq 74.038kHz

        DotClock    154.000000

        HTimings    1920 1968 2000 2080

        VTimings    1200 1203 1209 1235

        Flags   "-HSync" "+VSync"

    EndMode

    # Block type: 2:0 3:ff

    # Block type: 2:0 3:fc

    # Block type: 2:0 3:fd

EndSection

but the xrandr -q command returns:

Screen 0: minimum 640 x 400, current 1600 x 1200, maximum 1600 x 1200

default connected 1600x1200+0+0 0mm x 0mm

   1600x1200       0.0* 

   1280x1024       0.0  

   1152x864        0.0  

   1024x768        0.0  

   800x600         0.0  

   640x480         0.0  

   720x400         0.0

When I try to set the resolution, I get:

$ xrandr --fb 1920x1200

xrandr: screen cannot be larger than 1600x1200 (desired size 1920x1200)



$ xrandr --output DVI-0 --auto

warning: output DVI-0 not found; ignoring

How can I set the screen resolution to 1920x1200?
Why doesn't xrandr identify the DVI-0 output?

Note that the same computer running Ubuntu version higher than 10.04 detects the correct resolution with no problems. On this machine I cannot upgrade due to some legacy hardware compatibility problems.

Also, I don't see any optional screen drivers available in the Hardware Drivers dialog.

----

UPDATE:

following the answer to this question, I got some advance. Now the required mode is listed in the xrandr -q list, but I can't switch to that mode. Using the Monitors applet (which now shows the new mode), I get the response that:

The selected configuration for displays could not be applied. Could not set the configuration to CRTC 262.

From the command line it looks like this:

$ cvt 1920 1200 60

# 1920x1200 59.88 Hz (CVT 2.30MA) hsync: 74.56 kHz; pclk: 193.25 MHz

Modeline "1920x1200_60.00"  193.25  1920 2056 2256 2592  1200 1203 1209 1245 -hsync +vsync



$ xrandr --newmode "1920x1200_60.00"  193.25  1920 2056 2256 2592  1200 1203 1209 1245 -hsync +vsync



$ xrandr -q

Screen 0: minimum 640 x 400, current 1600 x 1200, maximum 1600 x 1200

default connected 1600x1200+0+0 0mm x 0mm

   1600x1200       0.0* 

   1280x1024       0.0  

   1152x864        0.0  

   1024x768        0.0  

   800x600         0.0  

   640x480         0.0  

   720x400         0.0  

  1920x1200_60.00 (0x120)  193.0MHz

        h: width  1920 start 2056 end 2256 total 2592 skew    0 clock   74.5KHz

        v: height 1200 start 1203 end 1209 total 1245           clock   59.8Hz



$ xrandr --addmode default 1920x1200_60.00



$ xrandr -q

Screen 0: minimum 640 x 400, current 1600 x 1200, maximum 1600 x 1200

default connected 1600x1200+0+0 0mm x 0mm

   1600x1200       0.0* 

   1280x1024       0.0  

   1152x864        0.0  

   1024x768        0.0  

   800x600         0.0  

   640x480         0.0  

   720x400         0.0  

   1920x1200_60.00   59.8  



$ xrandr --output default --mode 1920x1200_60.00

xrandr: Configure crtc 0 failed

Another piece of info (if it helps anyone):

$ sudo lshw -c video

  *-display UNCLAIMED     

       description: VGA compatible controller

       product: ATI Technologies Inc

       vendor: ATI Technologies Inc

       physical id: 1

       bus info: pci@0000:00:01.0

       version: 00

       width: 32 bits

       clock: 33MHz

       capabilities: pm pciexpress msi bus_master cap_list

       configuration: latency=0

       resources: memory:c0000000-cfffffff(prefetchable) ioport:f000(size=256) memory:feb00000-feb3ffff

----

UPDATE 2: Here's the updated lshw listing:

$ sudo lshw -numeric -c video

  *-display UNCLAIMED     

       description: VGA compatible controller

       product: ATI Technologies Inc [1002:9802]

       vendor: ATI Technologies Inc [1002]

       physical id: 1

       bus info: pci@0000:00:01.0

       version: 00

       width: 32 bits

       clock: 33MHz

       capabilities: pm pciexpress msi bus_master cap_list

       configuration: latency=0

       resources: memory:c0000000-cfffffff(prefetchable) ioport:f000(size=256) memory:feb00000-feb3ffff

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brailloni

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answered 3 Years ago epypian · Accepted Answer

I think you will have gotten somewhere when you get this to increase:



Screen 0: minimum 640 x 400, current 1600 x 1200, maximum 1600 x 1200    

                                                  ⇑⇑⇑⇑⇑⇑⇑⇑⇑⇑⇑

Then, I think, you will be able to get xrandr to use the custom mode you've learned how to define (if you still need it after fixing the basic problem).

Increase Virtual Screen Size

[This][1] article suggests adding a Virtual line to the Screen section of a xorg.conf configuration file to set the maximum screen size. It's from a couple of years ago. When testing this I wasn't able to set the Virtual line past the maximum screen size given by xrandr -q, however. With my driver and hardware that value was an already quite large 8192x8192, however.

You could experiment by adding this as /etc/X11/xorg.conf, for example:



Section "Screen"

    Identifier "My Screen"

    Subsection "Display"

        Virtual 2048 2048

    EndSubSection

EndSection

You will probably not see a /etc/X11/xorg.conf as today's video drivers will attempt to determine reasonable defaults for everything and modern distributions leave that file out. It will be used if present, however.

If you do already have an /etc/X11/xorg.conf file you can try adding the above Virtual line to the Display subsection of its Screen section

I suggest you test this with a command line editor since there's some chance it will mess up your ability to sign on with the Ubuntu GUI and you may need to do Alt-Ctrl-F1, sign on, and edit (or remove) the file using command line tools. Any errors should in /var/log/Xorg.0.log or /var/log/Xorg.1.log.

In fact, you could and should test this by logging into an additional userid on your system (without logging out of your usual userid) and checking from the new session, that way you can use Alt-Ctrl-F7 to go back to your working GUI if there's trouble. In the case that you are using an additional user id to log in without logging out of the first the appropriate log will be /var/log/Xorg.1.log. Don't log out of the working session or boot until you have a working xorg.conf or have again removed it.

Use a Different Graphics Driver

Another article I read resolved this problem by switching drivers, but I see from your question that the Additional Drivers program doesn't give you any alternatives. (I assume that's what you mean above when you mention the "Hardware Drivers dialog". Unless you change drivers with the Additional Drivers program you will use a driver the kernel deems appropriate for your video card or the video logic on your motherboard.

For the OP, from what you described in your comments above it appears that your system should be using the radeon driver, but isn't. I use the radeon driver and commonly set my horizontal resolution to 1920 (max for the driver/card seems to be 8192). The vesa and fb drivers are very basic drivers for old hardware--old enough that monitors of that era didn't have very large displays.

Upgrade Ubuntu

If you are running a computer newer than the Ubuntu version you have installed and, in particular, its Linux kernel it's completely possible that the kernel won't recognize your graphics adapter. If that's the case you need to upgrade your Ubuntu software which contains support for your equipment.

Since he can't get fglrx to run, this unfortunately is the case for ysap. Because of the newness of this equipment relative to the release ysap is running, there is no support for [1002.9802] in the Lucid (or Maverick either) Linux kernel. First support for this equipment appeared in the Natty 2.6.38 kernel. To check for support for a particular device in kernel modules you can go to /lib/modules/kernel-version/module.alias file and search for the adapter's value. For that equipment:

grep v00001002d00009802 /lib/modules/2.6.38-10-generic/modules.alias

To check Natty's kernel support. It replies:

alias pci:v00001002d00009802sv*sd*bc*sc*i* radeon

As a test, you can try to boot a live CD on the system and try to set the resolution you desire in that environment (click on Try Ubuntu, rather than Install).

Getting appropriate driver support can also enable modern graphics facilities like direct rendering and OpenGL support, greatly improving performance and aesthetics.

For a personal computer you may also be able to use an upgraded kernel if a compatible one is available for your version of Ubuntu. For a production computer it may be necessary to upgrade Ubuntu to a newer version, when available, for the sake of reliability and robustness.