Subject: Re: [mmotm and linux-next][PATCH] irq: enclose irq_desc_lock_class in CONFIG_LOCKDEP

From: Ingo Molnar <[email-masked]>
Date: Tue, 16 Dec 2008 11:23:40 +0100

* Ingo Molnar <[email-masked]> wrote:

> > >  #include "internals.h"
> > >  
> > > +#ifdef CONFIG_LOCKDEP
> > >  /*
> > >   * lockdep: we want to handle all irq_desc locks as a single lock-class:
> > >   */
> > >  static struct lock_class_key irq_desc_lock_class;
> > > +#endif
> > >  
> > >  /**
> > >   * handle_bad_irq - handle spurious and unhandled irqs
> > > 
> > 
> > No, lockdep.h (which we forgot to include) already handles that:
> > 
> > # define lockdep_set_class(lock, key)		do { (void)(key); } while (0)
> > 
> > the problem is that the code which references irq_desc_lock_class is
> > inside #ifdef CONFIG_SPARSE_IRQ, so this is a better fix:
> 
> agreed that this is the better fix - applied to tip/irq/sparseirq, 
> thanks!

actually, this breaks the build on !SPARSEIRQ because we will use that 
class in the non-sparseirq case. So we've converted a build warning to a 
build failure ;-)

	Ingo