Messages in this thread | | | From | Kevin Hilman <> | Subject | Re: [PATCH v3 3/4] irq: Allow multiple clients to register for irq affinity notification | Date | Fri, 26 Sep 2014 08:10:04 -0700 |
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Russell King - ARM Linux <linux@arm.linux.org.uk> writes:
> On Fri, Sep 26, 2014 at 11:29:56AM +0200, Thomas Gleixner wrote: >> On Thu, 25 Sep 2014, Kevin Hilman wrote: >> > Maybe I'm missing something, or maybe we're just lucky and nobody uses >> > them together, but irq_set_affinity_notifier() only allows a single >> > notifier to be registered at any given time. So if you had a system >> >> A single notifier per irq ..... > > So what about two drivers wanting to use this notifier, but sharing an > interrupt? > > It sounds to me like this notifier was misdesigned from the very start, > and it should always have supported multiple notifiers.
I agree.
$SUBJECT patch tries to add that support, and is part of a series wanting to use these notifiers in the PM QoS subsystem, while at the same time not breaking existing users.
I suppose this series could be written without $SUBJECT patch, and crossing fingers in the hopes that an existing user of the notifiers doesn't also need to use the pm_qos constraints, but that seems like knowingly leaving an armed landmine laying around.
Kevin
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