[SOLVED] Problem configuring DisplayLink monitor (udlfb...)

Question

SOLVED:
It seems that my monitor shows no green screen when it is ready. Instead it shows the last image rendered. In my case it was this color stripes.
Also, I upgraded to kernel 3.2.1-2, and using the include module udlfb and xf86-video-fbdev from the official repositories I made it work.
I'm struggling to configure a Green House DisplayLink monitor to work with a netbook with an eGalaxTouchscreen. It seems I have problems with udlfb and the DisplayLink driver.
Following this artilce in the wiki, I installed udlfb and xf86-video-fbdev-for-displaylink from the AUR.
Loading the module with
# modprobe udlfb fb_defio=1
does not give any problem:
dmesg
[ 509.963703] usbcore: registered new interface driver udlfb
Plugging the monitor after loading the driver gives the following output:
dmesg
[ 637.363419] usb 1-1: new high speed USB device number 6 using ehci_hcd
[ 637.470050] usb 1-1: device descriptor read/64, error -32
[ 637.701889] udlfb: DisplayLink GH-USD16K - serial #USD16K3310398
[ 637.701899] udlfb: vid_17e9&pid_016b&rev_0196 driver's dlfb_data struct at f377b800
[ 637.701905] udlfb: console enable=0
[ 637.701909] udlfb: fb_defio enable=1
[ 637.702124] udlfb: vendor descriptor length:17 data:17 5f 01 0015 05 00 01 03 00 04
[ 637.702132] udlfb: DL chip limited to 1500000 pixel modes
[ 637.702251] udlfb: allocated 4 65024 byte urbs
[ 637.785022] udlfb: 1366x768 valid mode
[ 637.785034] udlfb: Reallocating framebuffer. Addresses will change!
[ 637.788011] udlfb: 1366x768 valid mode
[ 637.788019] udlfb: set_par mode 1366x768
[ 637.793145] udlfb: DisplayLink USB device /dev/fb1 attached. 1366x768 resolution. Using 4104K framebuffer memory
But there is no visible change, the screen remains black. Nevertheless, there is a new entry /dev/fb1 as advertised. I followed the steps of the article but I didn't suceed. As I understand, the green screen assures you that udlfb is properly loaded and that the monitor is ready to use.
It seems that it is sadly not my case. Another strange thing is that if I load udlfb, then unload it and load it back again the monitor diplays green, blue, red and yellow stripes. But not the green screen.
I attach my xorg configuration, just in case.
/etc/X11/xorg.conf.d/10-monitor.conf
# eGalax TouchScreen
Section "Monitor"
Identifier "LVDS1"
EndSection
Section "Device"
Identifier "eGalaxTouchscreen"
Driver "intel"
BusID "PCI:0:2:0"
EndSection
Section "Screen"
Identifier "eGalaxScreen"
Device "eGalaxTouchscreen"
Monitor "LVDS1"
DefaultDepth 16
SubSection "Display"
Depth 16
Modes "1366x768"
EndSubSection
EndSection
# Green House DisplayLink Monitor
Section "Monitor"
Identifier "GreenHouseMonitor"
EndSection
Section "Device"
Identifier "GreenHouseMonitor"
Driver "fbdev"
BusID "USB"
Option "fbdev" "/dev/fb1"
# Option "rotate" "CCW"
EndSection
Section "Screen"
Identifier "GreenHouseScreen"
Device "GreenHouseMonitor"
Monitor "GreenHouseMonitor"
DefaultDepth 16
SubSection "Display"
Depth 16
Modes "1366x768"
EndSubSection
EndSection
# Dual Monitor configuration
#Section "ServerLayout"
# Identifier "eGalaxAsMainDisplay"
# Screen 0 "eGalaxScreen"
# Screen 1 "GreenHouseScreen" RightOf "eGalaxScreen"
# Option "Xinerama" "on"
#EndSection
Section "ServerLayout"
Identifier "GreenHouseAsMainDisplay"
Screen 0 "GreenHouseScreen"
Screen 1 "eGalaxScreen" RightOf "GreenHouseScreen"
Option "Xinerama" "on"
EndSection
Last edited by gjasso (2012-01-25 13:22:29)

Answer 1

I use my DisplayLink monitor with a netbook. The best I can get at the moment is to use the DL monitor as my primary monitor in a []single monitor setup[]. This means that my netbook's monitor is not used at all (although in my case it is not vital, I would like it to work for watching videos or writing LaTeX code in the smaller screen with a big font size and read the preview in the bigger one).
This is the Xorg file I use:
/etc/X11/xorg.conf.d/10-monitor.conf
# DisplayLink Monitor
Section "Device"
Identifier "DisplayLink"
Driver "fbdev"
BusID "USB"
Option "fbdev" "/dev/fb1"
EndSection
Section "Monitor"
Identifier "Secondary Monitor"
EndSection
Section "Screen"
Identifier "External Screen"
Device "DisplayLink"
Monitor "Secondary Monitor"
DefaultDepth 16
SubSection "Display"
Depth 16
Modes "1366x768"
# Virtual 4096 4096
EndSubSection
EndSection
# eGalax Touchscreen
Section "Device"
Identifier "Integrated Graphics Controller"
Driver "intel"
EndSection
Section "Monitor"
Identifier "Primary Monitor"
EndSection
Section "Screen"
Identifier "Internal Screen"
Device "Integrated Graphics Controller"
Monitor "Primary Monitor"
DefaultDepth 16
SubSection "Display"
Depth 16
Modes "1366x768"
Virtual 2732 768
EndSubSection
EndSection
# Dual Monitor configuration
Section "ServerLayout"
Identifier "Dual Head Setup"
# Screen "Internal Screen"
# Screen "External Screen" RightOf "Internal Screen"
Screen "External Screen"
# Screen "Internal Screen" LeftOf "External Screen"
# Screen "Internal Screen" LeftOf "External Screen"
# Option "Xinerama" "on"
# Option "Clone" "off"
EndSection
I use xf86-input-fbdev for the DL monitor.
This has one major drawback: I've found no way to make this work dynamically, so I need to move/rename or edit this file whenever I want to change my setup (twice a day in my case). It is not absolutely unbearable but it is an unsatisfactory solution nevertheless.
Also, if I understood correctly, this seems to be a limitation of the current drivers (which include no 3D accel., so no GNOME shell for example). If you find a better way to do it (specially to detect the other monitor dynamically) please let me know.
PS: Sorry for the late response, I was on vacation.