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From: Mark Brown <broonie-yzvPICuk2AATkU/dhu1WVueM+bqZidxxQQ4Iyu8u01E@public.gmane.org>
Subject: Re: Threaded interrupts for synaptic touchscreen in HTC dream
Date: Wed, 22 Jul 2009 15:32:11 +0100
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To: Thomas Gleixner <tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org>
Cc: Peter Zijlstra <peterz-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>, Dmitry Torokhov <dmitry.torokhov-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>, Trilok Soni <soni.trilok-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>, Pavel Machek <pavel-+ZI9xUNit7I@public.gmane.org>, Arve Hj?nnev?g <arve-z5hGa2qSFaRBDgjK7y7TUQ@public.gmane.org>, kernel list <linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>, Brian Swetland <swetland-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>, linux-input-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Andrew Morton <akpm-3NddpPZAyC0@public.gmane.org>, linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Joonyoung Shim <jy0922.shim-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>, m.szyprowski-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org, t.fujak-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org, kyungmin.park-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org, David Brownell <david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org>, Daniel Ribeiro <drwyrm-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
List-Id: linux-i2c@vger.kernel.org

On Wed, Jul 22, 2009 at 04:18:26PM +0200, Thomas Gleixner wrote:
> On Wed, 22 Jul 2009, Peter Zijlstra wrote:

> > Also, how important is it that subhandler1..n run in their own thread?
> > That is, can't we let them run from the thread that is otherwise waiting
> > for the completino anyway?

> In those cases I suspect we can do that. I guess there can be async
> handling as well: the main handler queries the pending interrupts,
> masks them, wakes the handlers and returns. No wait for all threads to
> finish necessary before unmasking the main interrupt line.

The chips I'm deling with can certainly support doing that but I'm not
sure there'd be enormous advantages - a lot of the interrupt handlers
will either be trivial (eg, RTC ticks or alarms) or be serialised by a
need to interact with the chip anyway.  I'd expect this to be generally
true, though ICBW.