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Date: Sat, 24 Jun 2017 14:13:35 +0200 (CEST)
From: Thomas Gleixner <tglx@linutronix.de>
To: "Rafael J. Wysocki" <rafael@kernel.org>
cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
        Brian Norris <briannorris@chromium.org>,
        Heiko Stuebner <heiko@sntech.de>,
        Linus Walleij <linus.walleij@linaro.org>,
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        LKML <linux-kernel@vger.kernel.org>, linux-gpio@vger.kernel.org,
        John Keeping <john@metanate.com>, Linux PM <linux-pm@vger.kernel.org>,
        Doug Anderson <dianders@chromium.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Tony Lindgren <tony@atomide.com>,
        "Rafael J. Wysocki" <rjw@rjwysocki.net>
Subject: Re: PM / wakeirq: Convert to SRCU
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On Sat, 24 Jun 2017, Rafael J. Wysocki wrote:
> On Sat, Jun 24, 2017 at 11:56 AM, Thomas Gleixner <tglx@linutronix.de> wrote:
> > The wakeirq infrastructure uses RCU to protect the list of wakeirqs. That
> > breaks the irq bus locking infrastructure, which allows sleeping functions
> > to be called so interrupt controllers behind slow busses, e.g. i2c, can be
> > handled.
> >
> > The wakeirq functions hold rcu_read_lock and call into irq functions, which
> > in case of interrupts using the irq bus locking will trigger a
> > might_sleep() splat.
> >
> > Convert the wakeirq infrastructure to Sleepable RCU and unbreak it.
> >
> > Fixes: 4990d4fe327b ("PM / Wakeirq: Add automated device wake IRQ handling")
> > Reported-by: Brian Norris <briannorris@chromium.org>
> > Suggested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
> > Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> > Cc: stable@vger.kernel.org
> 
> OK
> 
> I guess it would be good to get this into 4.12?

I think so, but it probably wants some testing and breeding in next.

Thanks,

	tglx