Subject: common clock framework

From: [email-masked] (Mike Turquette)
Date: Sun, 6 May 2012 16:49:58 -0700

On 20120505-13:33, Raul Xiong wrote:
> 2012/5/5 Turquette, Mike <[email-masked]>
> > Bad news: lockdep gets cranky about possible deadlocks due to holding
> > prepare_lock and then trying to hold it again in a rate-change
> > notifier handler (from OMAP's regulator code).  Specifically
> >
> 
> Glad to see common clock framework will support DVFS. Can we use different
> spinlock for different clocks with different lockdep lock classes to avoid
> the dead lock and lockdep warnings?

I understand that different lockdep classes could allow for nested
locking, but I don't have a good idea of how that would actually be
implemented.  Could you elaborate a bit more?

In the mean time I'm looking at some different locking semantics that
don't involve lockdep class mangling, just a more fine-grained approach
to locking exactly what we want.

Regards,
Mike