Displaylink Driver For Linux
I have a USB2 displaylink adapter connected to my machine so as to make use of that nice second monitor I have here. The primary graphics card is the dreaded Poulsbo, so there's no hardware acceleration to worry about (makes no difference in Emacs anyway ;-).
So I'm using a trivial xorg.conf with just:
DisplayLink has recently updated their DisplayLink USB 3.0 driver for the latest Ubuntu Linux operating system launched by Canonical in the last week of April 2016, Ubuntu 16.04 LTS. The latest version of the DisplayLink USB Graphics Software, build 1.1.62, is available now for all supported Ubuntu Linux. The driver readme does not mention DisplayLink, but it does mention some required audio and Ethernet drivers for Windows. Sometimes Linux 'just works' without needing any extra drivers. But the best dock choice for me is always one that doesn't need any drivers, like the Thinkpad Ultra Dock 40A2, for example.
The X server starts up OK but only the main (i.e. Poulsbo-connected) display gets used. The other card is detected (as evidenced by 'xrandr --list-providers' output), but 'not enough' (as evidenced by the fact that only one output shows up in 'xrandr'):
The Xorg.0.log file doesn't have any special (WW) or (EE), except for the expected glamor/aiglx failures. The only other hint of possible problem I see is when I start 'xinit' I get:
So my question is: how can I enable the output on my second (displaylink) card? Or alternatively, where can I find further info (since web-searches lead me nowhere because the 'modesetting' keyword ends up matching lots of irrelevant threads about other drivers)?
DavidPostill♦
1 Answer
The new DisplayLink driver (udldrmfb) piggy backs off your graphics card, in my case, I wish to use the Intel DRI/OpenGL, yet use USB for display. udlfb is old and should be blacklisted. fbdev doesn't give you hardware acceleration.
Out of the box, if plugged in before boot, my screen works with no xorg.conf
However, I wanted a working Xorg.conf so I could tweak / use with Mali (ARM) on an Odroid, which requires a Xorg.conf
BusID and kmsdev will need tweaking for your particular setup, see lspci and /sys/class/drm/. The Monitor section can be omitted if your monitor has a proper EDID.
Environment:Ubuntu 14.04.1, 3.19.0-9-generic kernel, Intel i7-4770R, Iris Pro 5200, Mimo USB screen.