Unable to get native 1920x1200 resolution on Dell 2407WFP

joetheprogrammer · 10-05-2007, 10:00 PM

Hi,

I'm experiencing problems getting my Dell 24" flatpanel monitor to use its native resolution, 1920x1200 in Linux. I can achieve this easily under Windows and Mac OS X, so there's nothing wrong with the monitor. Right now I'm running it at 1680x1050, which is as high as I've managed to get it. When I run

Code:

xrandr --output TMDS-1 --mode 1920x1200

My monitor goes black, and then it says "Received out of range signal. Please set to 1920x1200 @ 60Hz." At this point I try running Xrandr (in verbose mode) from my laptop display, and I get the following output:

Code:

Screen 0: minimum 320 x 200, current 1920 x 1200, maximum 1920 x 1920
LVDS connected 1280x800+0+0 (0x60) normal (normal left inverted right) 286mm x 178mm
        Identifier: 0x5d
        Timestamp:  1930678779
        Subpixel:   horizontal rgb
        Clones:    
        CRTC:       1
        CRTCs:      1
        EDID_DATA:
                00ffffffffffff0006105e9c00000000
                09100103801d13780a65219f5855872a
                29505400000001010101010101010101
                010101010101bc1b00a0502017303020
                36001eb2100000180000000100061020
                00000000000000000a20000000fe004e
                31333349312d4c30310a2020000000fc
                00436f6c6f72204c43440a2020200061
        BACKLIGHT: 296 (0x00000128) range:  (0,296)
  1280x800 (0x60)   71.0MHz -HSync -VSync
        h: width  1280 start 1328 end 1360 total 1440 skew    0 clock   49.3KHz
        v: height  800 start  803 end  809 total  823           clock   59.9Hz
  1024x768 (0x61)   65.0MHz -HSync -VSync
        h: width  1024 start 1048 end 1184 total 1344 skew    0 clock   48.4KHz
        v: height  768 start  771 end  777 total  806           clock   60.0Hz
  800x600 (0x62)   40.0MHz +HSync +VSync
        h: width   800 start  840 end  968 total 1056 skew    0 clock   37.9KHz
        v: height  600 start  601 end  605 total  628           clock   60.3Hz
  640x480 (0x63)   25.2MHz -HSync -VSync
        h: width   640 start  656 end  752 total  800 skew    0 clock   31.5KHz
        v: height  480 start  490 end  492 total  525           clock   59.9Hz
TMDS-1 connected 1920x1200+0+0 (0x64) normal (normal left inverted right) 0mm x 0mm
        Identifier: 0x5e
        Timestamp:  1930678779
        Subpixel:   horizontal rgb
        Clones:    
        CRTC:       0
        CRTCs:      0 1
  1920x1200 (0x64)  154.0MHz -HSync +VSync
        h: width  1920 start 1968 end 2000 total 2080 skew    0 clock   74.0KHz
        v: height 1200 start 1203 end 1209 total 1235           clock   60.0Hz
  1600x1200 (0x65)  161.0MHz -HSync +VSync
        h: width  1600 start 1712 end 1880 total 2160 skew    0 clock   74.5KHz
        v: height 1200 start 1203 end 1207 total 1245           clock   59.9Hz
  1680x1050 (0x66)  146.2MHz -HSync +VSync
        h: width  1680 start 1784 end 1960 total 2240 skew    0 clock   65.3KHz
        v: height 1050 start 1053 end 1059 total 1089           clock   60.0Hz
  1280x1024 (0x67)  135.0MHz +HSync +VSync
        h: width  1280 start 1296 end 1440 total 1688 skew    0 clock   80.0KHz
        v: height 1024 start 1025 end 1028 total 1066           clock   75.0Hz
  1280x1024 (0x68)  109.0MHz -HSync +VSync
        h: width  1280 start 1368 end 1496 total 1712 skew    0 clock   63.7KHz
        v: height 1024 start 1027 end 1034 total 1063           clock   59.9Hz
  1152x864 (0x69)  104.0MHz -HSync +VSync
        h: width  1152 start 1224 end 1344 total 1536 skew    0 clock   67.7KHz
        v: height  864 start  867 end  871 total  905           clock   74.8Hz
  1024x768 (0x6a)   78.8MHz +HSync +VSync
        h: width  1024 start 1040 end 1136 total 1312 skew    0 clock   60.1KHz
        v: height  768 start  769 end  772 total  800           clock   75.1Hz
  1024x768 (0x61)   65.0MHz -HSync -VSync
        h: width  1024 start 1048 end 1184 total 1344 skew    0 clock   48.4KHz
        v: height  768 start  771 end  777 total  806           clock   60.0Hz
  800x600 (0x6b)   49.5MHz +HSync +VSync
        h: width   800 start  816 end  896 total 1056 skew    0 clock   46.9KHz
        v: height  600 start  601 end  604 total  625           clock   75.0Hz
  800x600 (0x62)   40.0MHz +HSync +VSync
        h: width   800 start  840 end  968 total 1056 skew    0 clock   37.9KHz
        v: height  600 start  601 end  605 total  628           clock   60.3Hz
  640x480 (0x6c)   31.5MHz -HSync -VSync
        h: width   640 start  656 end  720 total  840 skew    0 clock   37.5KHz
        v: height  480 start  481 end  484 total  500           clock   75.0Hz
  640x480 (0x6d)   25.2MHz -HSync -VSync
        h: width   640 start  656 end  752 total  800 skew    0 clock   31.5KHz
        v: height  480 start  490 end  492 total  525           clock   60.0Hz
  640x480 (0x63)   25.2MHz -HSync -VSync
        h: width   640 start  656 end  752 total  800 skew    0 clock   31.5KHz
        v: height  480 start  490 end  492 total  525           clock   59.9Hz
  720x400 (0x6e)   28.3MHz -HSync +VSync
        h: width   720 start  738 end  846 total  900 skew    0 clock   31.5KHz
        v: height  400 start  412 end  414 total  449           clock   70.1Hz

Dell's website lists the following technical specifications for my monitor:

Code:

Horizontal Scan Frequency kHz:	30 kHz to 81 kHz (automatic)
Vertical Scan Frequency Frequency kHz:	56 Hz to 76 Hz (automatic) ), exception 1920 x 1200 at 60 Hz only

.
.
.
VESA, 1920 x 1200 - 74.0 kHz Horizontal, 60.0 Hz Vertical, 154 MHz

Here's the relevant sections of my xorg.conf file:

Code:

Section "Monitor"
        #DisplaySize      520   330     # mm
        Identifier   "Monitor0"
        VendorName   "DEL"
        ModelName    "DELL 2407WFP"
 ### Comment all HorizSync and VertRefresh values to use DDC:
        HorizSync    30.0 - 83.0
        VertRefresh  56.0 - 76.0
        Option      "DPMS"
EndSection

Section "Device"
        ### Available Driver options are:-
        ### Values: <i>: integer, <f>: float, <bool>: "True"/"False",
        ### <string>: "String", <freq>: "<f> Hz/kHz/MHz"
        ### [arg]: arg optional
        #Option     "NoAccel"                   # [<bool>]
        #Option     "SWcursor"                  # [<bool>]
        #Option     "ColorKey"                  # <i>
        #Option     "CacheLines"                # <i>
        #Option     "Dac6Bit"                   # [<bool>]
        #Option     "DRI"                       # [<bool>]
        #Option     "NoDDC"                     # [<bool>]
        #Option     "ShowCache"                 # [<bool>]
        #Option     "XvMCSurfaces"              # <i>
        #Option     "PageFlip"                  # [<bool>]
        Identifier  "Card0"
        Driver      "intel"
        VendorName  "Intel Corporation"
        BoardName   "Mobile 945GM/GMS/940GML Express Integrated Graphics Controller"
        BusID       "PCI:0:2:0"
EndSection

Section "Screen"
        Identifier "Screen0"
        Device     "Card0"
        Monitor    "Monitor0"
        SubSection "Display"
                Viewport   0 0
                Depth     1
        EndSubSection
        SubSection "Display"
                Viewport   0 0
                Depth     4
        EndSubSection
        SubSection "Display"
                Viewport   0 0
                Depth     8
        EndSubSection
        SubSection "Display"
                Viewport   0 0
                Depth     15
        EndSubSection
        SubSection "Display"
                Viewport   0 0
                Depth     16
        EndSubSection
        SubSection "Display"
                Viewport   0 0
                Depth     24
        EndSubSection
EndSection

It seems like the mode given by xrandr --verbose matches the one listed on Dell's website, so I'm really confused here. Help would be greatly appreciated.

Joe

GrapefruiTgirl · 10-05-2007, 10:37 PM

I must ask first, why do you want/need to use xrandr to get your display running? I have never used xrandr, so this question is both for my own education, as well as to understand why you are using it.

So anyway, in your Screen section you posted, there are no modes specified, nor any default colordepth. How come? It may help to actually put some video modes in there, even though they are 'optional'.

In the display section, add a line like DefaultDepth 16 and then in the Subsection "Display" for the 16 bit colordepth, add a line like Modes "1920x1200"

Finally, a minor detail: The horizscan range you have specified in your Monitor section is not exactly that which is specified in your monitors manufacturer specs. You may want to change that to 30 - 81 if for no other reason than to just have it set up to spec; it probably has nothing to do with your mode not working.

joetheprogrammer · 10-05-2007, 11:11 PM

>I must ask first, why do you want/need to use xrandr to get your display running?
There are three main reasons, really.

With 'xrandr --verbose', I can get detailed information on the detected display modes and what the sync and refresh rates are currently set at.
It allows me to change screen resolutions on the fly, as opposed to manually editing the xorg.conf file and restarting the X server each time.
I'm running this in clone mode with my laptop display, and this allows me to control each screen independently (changing the screen resolution within Gnome affects both monitors, so switching to 1920x1200 takes out both monitors at once).

>So anyway, in your Screen section you posted, there are no modes specified, nor
>any default colordepth. How come?
Basically, the reason is that I was too lazy. I created my xorg.conf file with 'X -configure', and then played around with all the screen settings with xrandr. However, just now I did try adding the desired resolution to the depth section and adding a default depth, although that failed to make a difference. Ditto with the horizontal scan correction.

GrapefruiTgirl · 10-05-2007, 11:27 PM

Interesting. Ok, thanks for the info about the xrandr thing anyway. Well, another way of approaching this would be to use a 'Modeline' in the Monitor section.

Using the XFree86 Modeline Calculator located HERE, I came up with the following modeline to generate the resolution you want, at 60 Hz:

Modeline "1920x1200@60" 210.68 1920 1952 2752 2784 1200 1224 1236 1261

I don't use modelines myself, so I'mnot sure if there's anything else BESIDES this modeline itself which needs to be added to the file, however the man page for xorg.conf should answer that question for you. Probably to guarantee that this modeline gets considered as the first choice by X, comment out the changes you may have made based on my last post, ie: the Modes line you may have added.

Good luck!

jschiwal · 10-06-2007, 02:21 AM

You can use the "gtf" program to generate a a custom modeline. I would recommend removing the ".00" from the name.

Example:

Code:

gtf 1920 1200 60 -x

  # 1920x1200 @ 60.00 Hz (GTF) hsync: 74.52 kHz; pclk: 193.16 MHz
  Modeline "1920x1200_60.00"  193.16  1920 2048 2256 2592  1200 1201 1204 1242  -HSync +Vsync

For lcd displays, I'd recommend only running them at the native resolution.

Electro · 10-06-2007, 06:19 AM

Since you are using a notebook computer with Intel 945GM graphics use 915resolution to reprogram one of the 16 modes, so the graphics chip can handle it. The 915resolution script have to be loaded before running GUI in the desire resolution. After you use the script, use the utility gtf to help create modelines. Then copy its output and paste into the monitor section.