joydev: Keyboards incorrectly identified as joystick

joydev: Keyboards incorrectly identified as joystick

[Jethro Beekman]

Or, really: "Keyboards incorrectly say they're a joystick". Some keyboard like
to say they have joystick capabilities while they don't. This results in a
joystick device showing up (e.g. in games) that is not calibrated and just
generally messes things up.

This seems to happen with multiple keyboards, mostly from Microsoft: e.g. the
Microsoft Digital Media Pro Keyboard and Microsoft Wired Keyboard 600.

Earlier reports on this mailing list:
http://thread.gmane.org/gmane.linux.kernel.input/25913
http://thread.gmane.org/gmane.linux.kernel.input/25926

Downstream bug reports:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/987877
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/390959

evtest output for certain keyboards:
https://launchpadlibrarian.net/112444244/evtest2
http://pastebin.com/tX4nnhAg

It would be easy to add an exception to joydev_match() like there currently are
for touchpads, tablets, etc. The question is: what should the test be? Or should
this be handled in userspace (udev)?

Jethro Beekman