[PATCH] of: Fix locking vs. interrupts

[David Miller]

From: Grant Likely <grant.likely at secretlab.ca>
Date: Wed, 12 Jun 2013 10:06:12 +0100

> On Wed, 12 Jun 2013 10:25:56 +0200 (CEST), Thomas Gleixner <tglx at linutronix.de> wrote:
>> On Wed, 12 Jun 2013, Benjamin Herrenschmidt wrote:
>> 
>> > The OF code uses irqsafe locks everywhere except in a handful of functions
>> > for no obvious reasons. Since the conversion from the old rwlocks, this
>> > now triggers lockdep warnings when used at interrupt time. At least one
>> > driver (ibmvscsi) seems to be doing that from softirq context.
>> > 
>> > This converts the few non-irqsafe locks into irqsafe ones, making them
>> > consistent with the rest of the code.
>> 
>> Fun. https://lkml.org/lkml/2013/2/4/416 seems to have got lost 
>>  
>> > Signed-off-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
>> > CC: <stable at vger.kernel.org> [v3.9+]
>> 
>> Acked-by: Thomas Gleixner <tglx at linutronix.de>
>> 
>> > ---
>> > 
>> > Note: It's silly to access the device-tree at interrupt time in most cases,
>> > and we should probably fix ibmvscsi, but for the time being, let's fix the
>> 
>> Right.
>> 
>> > obvious bug. Thomas, this can probably still go into 3.10... If not, I've
>> > CCed stable.
>> 
>> Should go through Grant I think.
> 
> Applied, thanks.

FWIW:

Acked-by: David S. Miller <davem at davemloft.net>