Comment # 3 on bug 1129258 from Takashi Iwai

(In reply to Nicolas Patricio Saenz Julienne from comment #2)
> I'm curious to know why is the i2c-device being removed.

It's from psmouse_smbus_disconnect().

And this sounds like a known problem, according to the comments in
psmouse_smbus_schedule_remove():

/*
 * This schedules removal of SMBus companion device. We have to do
 * it in a separate tread to avoid deadlocking on psmouse_mutex in
 * case the device has a trackstick (which is also driven by psmouse).
 *
 * Note that this may be racing with i2c adapter removal, but we
 * can't do anything about that: i2c automatically destroys clients
 * attached to an adapter that is being removed. This has to be
 * fixed in i2c core.
 */