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From: Tabi Timur-B04825 <B04825@freescale.com>
To: Grant Likely <grant.likely@secretlab.ca>
Subject: Re: Handling multiple GPIO controllers in 8xxx GPIO driver
Date: Thu, 29 Sep 2011 20:22:06 +0000
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	Felix Radensky <felix@embedded-sol.com>
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Grant Likely wrote:
> A chained handler has an expedited path through the interrupt code for
> handling it (basically, it skips handling it at the parent controller
> and passes through to the child, but it cannot handle multiple chained
> children on a single irq input.

So you can't do a shared chained handler?  If the chained handler returns=20
IRQ_NONE, the interrupt code just gives up?

Why is it called a "chained" handler?  Where's the chain?

I'm trying to understand the core interrupt code, and I can't seem to find=
=20
any descriptions of it.

--=20
Timur Tabi
Linux kernel developer at Freescale=