Re: [PATCH 0/3] Synaptics - fix lockdep warnings

[Arjan van de Ven <arjan@infradead.org>]

On Thu, 2006-09-14 at 10:58 -0400, Dmitry Torokhov wrote:
> On 9/14/06, Jiri Kosina <jikos@jikos.cz> wrote:
> > On Thu, 14 Sep 2006, Dmitry Torokhov wrote:
> >
> > > Can we add lock_class_key to the struct psmouse and use it to define
> > > per-device mutex class regardless of whether it is a child, grandchild
> > > or a parent?
> >
> > Hi Dmitry,
> >
> > what do you think about the patches below? I have used a slightly
> > different approach, as we also need to get rid of the spurious lockdep
> > warning in case of recursive call of serio_interrupt(), which can't be
> > handled well with lock subclass stored in struct psmouse. What do you
> > think about this? It shuts up the lockdep, and seems much cleaner to me.
> >
> 
> Yes, this is much, much better. Could you please tell me if depth
> should be a true depth or just an unique number? The reason I am
> asking is that I hope to get rid of parent/child pointers in serio
> (they were introduced when driver core could not handle recursive
> addition/removing of devices on the same bus).

lockdep sort of expects the depth to be a number between 0 and 7.
Other than that lockdep does not assume an ordering based on numerical
value at all; it figures that out at runtime.