Here’s a great application for USB displays. Hal Glenn from 2G Engineering has created an information display (on energy security and alternative methods of energy generation) with 9 USB touch screens, all running off a single Mac Mini running Ubuntu 9.10. And all using the available open source DisplayLink drivers and scripts and info at […]
Here’s how to add audio support on top of the previous instructions for getting USB multiseat running on Linux, with a Plugable UD-160-A type device. Add the following line to the bottom of the /lib/udev/rules.d/50-usbseat.rules file created per the previous instructions. KERNEL==”control*”, SUBSYSTEM==”sound”, SUBSYSTEMS==”usb”, PROGRAM=”/bin/cat /sys/%p/../../../../../devnum”, SYMLINK+=”usbseat/%c/sound” Then create a new /etc/X11/Xsession.d/50usbseat file which will […]
[updated 8/14/2011 with latest udlfb info] The xorg generic fbdev driver (xf86-video-fbdev) supports rotation with a custom option (note it disables DGA and xrandr when it rotated mode). DisplayLink devices can use this driver two ways: With the udlfb fb_defio option enabled to detect framebuffer writes based on page faults With the fbdev xorg server […]
Doing development on udlfb on Linux 2.6.32, crossed paths with these two quirks. The usb_skeleton.c sample driver appears to run afoul of this problem, resulting in a warn_on during bulk transfer completion, if done the way the sample recommends. Because completion routines can be called with irqs disabled, usb_buffer_free on dma-ready buffers can’t be called […]
I was embarrassed to discover that the ever-popular dlfb “green screen” is broken in subtle ways by the new defio support. So for now with this new driver, DL devices may up with what appears to be gibberish. I didn’t notice, because my test config launches X on the DisplayLink device immediately. In the absence […]
[update May 3, 2012: Support for using fb_defio and the standard, generic X fbdev driver is enabled by default, working, and stable with kernel 3.3 (at least). You’ll get lower CPU consumption and latency with DAMAGE notifications, but on many systems (especially higher end), fbdev is great. And because not everything supports DAMAGE, generic fbdev […]
For a USB virtual graphics solution, performance is critical. For the Linux drivers for DisplayLink devices, there are several patches and alternative implementations that are tough to evaluate, compare (and merge) without hard data. It would be great to know what compression ratio we’re getting, how much data is being sent over USB, etc. So, […]
Following on the announcement of Windows Multipoint Server 2010, HP has announced their first product to connect with it: The HP MultiSeat thin client T100. It’s a DisplayLink-based device with VGA, PS/2 keyboard and mouse ports, and audio. It’s a focused competitor to the product that Plugable sells here, and they do a great job […]
Soon, we’ll be able to plug inexpensive zero-state USB docks/terminals into new Linux systems, and a new graphical login will pop up in a completely plug and play fashion. Many users can then simultaneously share any single Linux PC. This is great for education, libraries, internet cafes, etc — anywhere where you have clusters of […]
[Update Dec 29, 2011: udlfb was promoted from the staging to the mainline kernel tree in 2.6.38. And in kernel 3.3 pagefault detection and console are enabled by default. See all our udlfb posts for the latest news.] [Update March 14, 2010: udlfb versions have moved to being released with the Linux kernel. Update on […]
