2013/5/13 David Herrmann [off-list ref]:

Anyway, I'd still like to see this patch applied so we have this annoying
bug fixed. I'd be willing to change the power_supply core, too, if one of the
maintainers agrees on the design (David? Anton?).

And, @Daniel, can you check whether this actually fixes the bug? I don't own
a device that reports battery-information, but it at least fixes the same bug
for the hid-wiimote driver (tested by me).

Yes, it does fixes the bug. Now udevadm properly show add and remove events
and upower happily get's them.
But there is around  15 seconds block on the bluetooth stack, in other words
when connecting a device it seems to probe the device which blocks till
a timeout, and while that timeout doesn't finish other bluetooth
devices are also
blocked. It seems the devices aren't able to be probed so soon, possibly
because bluetooth didn't finished setting them up. Looking at udevadm output
I clearly see that it locks for around 3 times.
My kernel knowledge is rather limited but if you can give me tips or patches to
test I really want to see this code finally working properly, and sorry for
not realizing when I sent it that it had this issue...

--
Daniel Nicoletti

KDE Developer - http://dantti.wordpress.com