One firmare version in the devices the driver takes care of is
completely broken and needs periodic pokes from our side. We
implemented this as a periodic delayed queue. The idea of the pokes
was taken from the suse enterprise kernel, in particular from Libor's
"Elo touchscreen firmware M workaround".

I am quoting him here:
  This patch adds periodic polling of the Elo USB touchscreens. Needed
  as a workaround for devices with M-level firmware, otherwise these
  devices are known to misbehave (as reported by Elo developers).

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Tested-by: Petr Ostadal <postadal@suse.cz>
Cc: Oliver Neukum <oliver@neukum.org>
Cc: Vojtech Pavlik <vojtech@suse.cz>
Cc: Egbert Eich <eich@suse.com>
Cc: Libor Pechacek <lpechacek@suse.cz>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>