Re: [PATCH] of: Fix locking vs. interrupts

From: David Miller
Date: Wed Jun 12 2013 - 05:15:48 EST


From: Grant Likely <grant.likely@xxxxxxxxxxxx>
Date: Wed, 12 Jun 2013 10:06:12 +0100

> On Wed, 12 Jun 2013 10:25:56 +0200 (CEST), Thomas Gleixner <tglx@xxxxxxxxxxxxx> 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@xxxxxxxxxxxxxxxxxxx>
>> > CC: <stable@xxxxxxxxxxxxxxx> [v3.9+]
>>
>> Acked-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
>>
>> > ---
>> >
>> > 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@xxxxxxxxxxxxx>
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