Win7 Plug and Play with the UGA-2K-A
Posted on 05. Mar, 2010 by Bernie Thompson in Windows
Attach your new Plugable USB graphics adapter to a Win 7 PC. What happens?
.. driver is found and downloaded from Microsoft’s Windows Update system…
… and a DisplayLink EULA and a bunch of screen flashes later …
Windows 7 and a network connection takes care of it. No driver disk needed.
Preparing more udlfb patches for linux-next
Posted on 12. Feb, 2010 by Bernie Thompson in udlfb
There are limits on how much a small device company can and should do in contributing to open source driver support. But with a historical connection to DisplayLink and more products coming with the technology included, contributing what we can to the generic DisplayLink driver on Linux makes some sense.
Also note this driver is just a foundation on which other stuff (like X) sits, so it doesn’t mean Linux is easy for real end users yet. But it’s getting closer.
Here’s the announce that went to the list today:
The next patch series for udlfb is “nearly ready” for submission, hopefully will be coming in the next few days.
Testing and any problem reports would be helpful. The code that will be submitted is at http://git.plugable.com/gitphp/index.php?p=udlfb&a=summary
There are many dozens of checkins in git as inter-related problems have been explored and the code incrementally improved. Before submitting, I’ll be reconstituting them into a smaller number of more analyzable email patches: make everything checkpatch.pl clean, reorganize things to match final layout, then per-feature patches. We’ll see how that goes.
Major features:
* Support for standard fbdev clients (via defio)
* Improved performance (about 20% average improvement over a variety of “benchmarks” like x11perf, gtkperf, glxgears)
* Asynchronous urb dispatch and no mutexes held for extended periods during render
* Slightly lower CPU consumption, less touching memory, slightly higher average compression
* Better handling of switching from X to fbcon VTs and back
* Driver should unload cleanly from either bottom-up (USB removal) or top-down (shutdown). Problem reports welcome.
* Performance metrics reported through sysfs (read /sys/class/graphics/fbX/*metrics*)
* EDID reported through sysfs (read /sys/class/graphics/graphics/fbX/edid)
* Can compile as module with or without defio or sys_ dependencies
* Lots of cleanup – tested on 64-bit, closer to endian clean, checkpatch.pl clean
What it does not have:
* The defio rendering problems (e.g. with xf86-video-fbdev X server) are still unsolved
* Still 16bpp only. Pseudo-truecolor 32->16 is on the wishlist.
* No DL 1×5 SKU detection yet (you’ll get a blank screen if your monitor’s res exceeds the adapter)
DisplayLink Linux Rotation
Posted on 02. Jan, 2010 by Bernie Thompson in udlfb
With a kernel framebuffer driver that supports defio (like the version of udlfb in testing at git.plugable.com), it’s possible to use the standard xf86-video-fbdev X driver, rather than a custom DisplayLink one.
One interesting gain is xf86-video-fbdev supports rotation with a custom option (note it disables DGA and xrandr when it rotated mode).
To enable, in the xorg.conf “Device” section, add a Rotate option, setting it to CW, CCW, or UD.
Section "Device" Identifier "dl" Driver "fbdev" Option "rotate" "CCW" Option "fbdev" "/dev/fb1" EndSection
One downside is rendering is significantly slower, as the extra work of rotation is done at the X level and the page-fault behavior of defio means even small updates refresh much of the screen. Here’s some numbers that can be compared to earlier posts (in non-rotate mode):
bernie@bernie-aspireone:~/git/misc-udlfb$ ./udlfb-perf.sh fb0 gtkperf -a Xlib: extension "RANDR" missing on display ":3.0". GtkPerf 0.40 - Starting testing: Fri Jan 1 09:47:20 2010 GtkEntry - time: 0.00 GtkComboBox - time: 3.73 GtkComboBoxEntry - time: 2.08 GtkSpinButton - time: 0.49 GtkProgressBar - time: 0.69 GtkToggleButton - time: 0.47 GtkCheckButton - time: 0.44 GtkRadioButton - time: 0.79 GtkTextView - Add text - time: 2.30 GtkTextView - Scroll - time: 1.24 GtkDrawingArea - Lines - time: 4.14 GtkDrawingArea - Circles - time: 4.56 GtkDrawingArea - Text - time: 4.11 GtkDrawingArea - Pixbufs - time: 0.90 --- Total time: 25.96 Quitting.. model name : Intel(R) Atom(TM) CPU N270 @ 1.60GHz model name : Intel(R) Atom(TM) CPU N270 @ 1.60GHz cpu MHz : 800.000 cpu MHz : 800.000 MemTotal: 2052144 kB Framebuffer Mode: 1920,1080 Rendered bytes: 1238913024 (total pixels * Bpp) Identical bytes: 1070725304 (skipped via shadow buffer check) sent bytes: 125732225 (compressed usb data, including overhead) K CPU cycles: 7478653 (transpired, may include context switches) % pixels found to be unchanged: 86.00 % Compression of changed pixels : 25.00 % Total CPU cycles spent per input pixel: 6 Total CPU cycles spent per output pixel: 59 USB Mbps: 35.52 (theoretical USB 2.0 peak 480)
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