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

From: Thomas Gleixner
Date: Wed Jun 12 2013 - 04:26:13 EST


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.

Thanks,

tglx
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