Re: [patch] Declare explicit, hardware based lock ranking in serio

[Dmitry Torokhov <dtor_core@ameritech.net>]

On Saturday 03 June 2006 04:50, Arjan van de Ven wrote:
> > Thanks.
> > 
> > So we're taking ps2->cmd_mutex and then we're recurring back into
> > ps2_command() and then taking ps2->serio->cmd_mutex.
> > 
> > I suspect that's all correct/natural/expected and needs another
> > make-lockdep-shut-up patch.
> 
> 
> The PS/2 code has a natural device order and there is a one level
> recursion in this device order in terms of the cmd_mutex; annotate 
> this explicit recursion as ok
> 

It is not necessarily single depth - one could have 2 or more pass-through
ports chained together, although currently in kernel we only have Synaptics
pass-through. If we were ever to implement pass-through port for IBMs
trackpoints then we'd have:

	Synaptics<->pass-through<->TP<->pass-through<->some mouse

-- 
Dmitry