Re: [PATCH] 6700/6702PXH quirk

[Andrew Morton <akpm@osdl.org>]

Kristen Accardi <kristen.c.accardi@intel.com> wrote:
>
> On Fri, 2005-08-05 at 15:26 -0700, Andrew Morton wrote:
> > Kristen Accardi <kristen.c.accardi@intel.com> wrote:
> 
> > > +	if (!quirk)
> > > +		return -ENOMEM;
> > > +	
> > > +	INIT_LIST_HEAD(&quirk->list);
> > > +	quirk->dev = dev;
> > > +	list_add(&quirk->list, &msi_quirk_list);
> > > +	return 0;
> > > +}
> > 
> > Does the list not need any locking?
> 
> Actually, I'm glad you asked that question because I was wondering that
> myself.  The devices are added to the list at boot time, and after that
> time, the list will never change.  Does PCI enumeration happen on all
> processors?  I thought maybe it only happened on one.  In that case we
> don't need a lock I don't think.  
> 

do_basic_setup() is called after SMP is up and running.  do_basic_setup()
calls driver_init() and most of the initcalls.  Plus there's kernel
preemption.

So yup, I think you need locking..