quoted

quoted

I refuse it because it will be supported by exactly 1 driver in the
kernel - gpio-keys. It is the only driver that allows shut half of the
"device" (because in reality it is a group of disjoint devices). It is
the only case when "muting" a button means that IRQ is shut off abnd
thus CPU can continue to sleep if that button is pressed. For all other
devices that have 1 inettrupt per device, you still have to wake up,
because you don't know whether the button that generated event is
"important" or not.

Fair enough.

quoted

Now, there is a issue of waking up userspace task, additional scheduling
and keeping CPU running longer than necessary for "uninteresting" keys.
This can be solved by implementing a subscription model which allows
filtering uninteresing events on a per-client basis at evdev level.

Right. And for gpio_keys, this would be dine on the driver level.

But the semantics are different - if done on driver level you'd be
affecting _all_  consumers of the device; what I want to be done only
affects owner of the file descriptor.

Well, if _all_ consumers decide to ignore some key, we should be able
to ignore it at driver level.

And actually it may make some sense -- I do not think disabling irq
during runtime is worth the effort, but disabling wakeup source and
getting rid of unneccessary wakeup when system is suspended is
probably worth it.

									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html