Re: [PATCH v2] PM / wakeirq: Convert to SRCU

From: Brian Norris
Date: Mon Jun 26 2017 - 16:37:39 EST


On Sun, Jun 25, 2017 at 07:31:13PM +0200, Thomas Gleixner wrote:
> The wakeirq infrastructure uses RCU to protect the list of wakeirqs. That
> breaks the irq bus locking infrastructure, which is 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@xxxxxxxxxxxx>
> Suggested-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> ---
> drivers/base/power/wakeup.c | 32 ++++++++++++++++++--------------
> 1 file changed, 18 insertions(+), 14 deletions(-)

This resolves the warnings I've seen, for sure. And I don't seem to have
any new suspend/resume problems, so:

Tested-by: Brian Norris <briannorris@xxxxxxxxxxxx>