Problem getting two monitors running in 12,X

I have a motherboard with RADEON 4200 video. I also have a PCI
card which is RADEON 5450. The video outputs feed two identical
SAMSUNG monitors. At one point I (before version 12), I was able
to run the two monitors as an xinerama display. Once I upgraded
to 12X, only the monitor connected to the motherboard video output
worked. I mucked with xorg.conf, but never got anything to work.

Anyway, after a couple of years of living with only one monitor, I’ve been playing
with xorg.conf file for this again, and I now have the following in my xorg.conf file:


Section “Monitor”
Identifier “SAM0”
VendorName “SAM”
ModelName “SyncMaster”
HorizSync 30.0 - 81.0
VertRefresh 56.0 - 75.0
Option “DPMS”
EndSection

Section “Monitor”
Identifier “SAM1”
VendorName “SAM”
ModelName “SyncMaster”
HorizSync 30.0 - 81.0
VertRefresh 56.0 - 75.0
Option “DPMS”
EndSection

Section “Device”
Identifier “HD4200”
Driver “radeon”
VendorName “ATI Technologies Inc”
BoardName “Cedar [Radeon HD4200]”
BusID “PCI:1:5:0”
EndSection

Section “Device”
Identifier “HD5450”
Driver “radeon”
VendorName “ATI Technologies Inc”
BoardName “Cedar [Radeon HD5450]”
BusID “PCI:4:0:0”
EndSection

Section “Screen”
Identifier “Screen0”
Device “HD4200”
Monitor “SAM0”
SubSection “Display”
Depth 24
Viewport 0 0
Modes “1280x1024”
EndSubSection
EndSection

Section “Screen”
Identifier “Screen1”
Device “HD5450”
Monitor “SAM1”
SubSection “Display”
Viewport 0 0
Depth 24
Modes “1280x1024”
EndSubSection
EndSection


When I boot the system, the monitor associated with the 4200 board
works and the other remains dead.

I get the following messages in Xorg.0.log about VGA-1 and RADEON(1).
These should be the ones associated with the 5450 board.

47.819] (II) RADEON(1): Output VGA-1 has no monitor section
47.885] (II) RADEON(1): EDID for output VGA-1
47.885] (II) RADEON(1): Output VGA-1 disconnected

Apparently, VGA-0 is set by default to the 4200 display. How do I force
an association of VGA-1 with the 5450 board/monitor section in the
xorg.conf file?

Thanks

Larry

You were missing the Server Section. Use the following. I left out the Input Device and Monitor Sections (they are not needed – just let X do the configuration for them), as well as dropped the monitor stuff from the Screen Section. You don’t need the Vendor and Board name stuff in the Device section either, but its harmless.

######################################
#     Server Layout(s) Section       #
######################################

Section "ServerLayout"
    Identifier     "Call_it_whatever_you_want"
    Screen      0  "Screen0" 0 0
    Screen      1  "Screen1" LeftOf "Screen0"
    Option        "Xinerama" "on"
EndSection


###############################################
#      Graphics Device Adaptor(s) Section     #
###############################################

Section "Device"
    Identifier "HD4200"
    Driver "radeon"
    VendorName "ATI Technologies Inc"
    BoardName "Cedar [Radeon HD4200]"
    BusID "PCI:1:5:0"
EndSection

Section "Device"
    Identifier "HD5450"
    Driver "radeon"
    VendorName "ATI Technologies Inc"
    BoardName "Cedar [Radeon HD5450]"
    BusID "PCI:4:0:0"
EndSection

############################
#    Screen(s) Section     #
############################

Section "Screen"
    Identifier "Screen0"
    Device "HD4200"
    SubSection "Display"
          Depth 24
          Viewport 0 0
    EndSubSection
EndSection

Section "Screen"
    Identifier "Screen1"
    Device "HD5450"
    SubSection "Display"
          Viewport 0 0
          Depth 24
    EndSubSection
EndSection

OK –

I did have a ServerLayout section in the file. I just didn’t copy it over.

So I made the changes you suggested, and I get the same error. No VGA-1
monitor section. Here’s the results when I do a grep of Xorg.0.log for VGA:

45.659] (II) RADEON(0): Output VGA-0 has no monitor section
45.691] (II) RADEON(0): EDID for output VGA-0
45.691] (II) RADEON(0): Printing probed modes for output VGA-0
45.693] (II) RADEON(0): Output VGA-0 connected
45.693] (II) RADEON(0): Output VGA-0 using initial mode 1280x1024
45.761] (II) RADEON(1): Output VGA-1 has no monitor section
45.827] (II) RADEON(1): EDID for output VGA-1
45.827] (II) RADEON(1): Output VGA-1 disconnected

As before, it’s somehow connecting VGA-0 to RADEON(0) which is the RADEON
4200 on the motherboard, but it is not doing the same for RADEON(1) and as a result,
I have video on one monitor and nothing on the other.

Larry

post the full xorg log to suse paste and then provide a link SUSE Paste

also post the output of

xrandr --screen 0 & xrandr --screen 1

also check your cabling (pins on the card’s and monitors and that on both ends of the cables)

Very interesting –

It’s now working. I tried checking the cables and when I swapped the cables, the display did
not move from one screen to the other UNTIL I turned off/on the non-working monitor. So it
was the monitor not responding. Works fine now.

I have one residual problem that I can live with – randr gives an error message when the system
is rebooted. Annoying, but I’m happy to ignore the error since my two screen display is working’
again.

Thanks for the help.

Larry