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Sender: Grant Likely <glikely@secretlab.ca>
Date: Thu, 29 Sep 2011 12:27:37 -0500
From: Grant Likely <grant.likely@secretlab.ca>
To: Tabi Timur-B04825 <B04825@freescale.com>
Subject: Re: Handling multiple GPIO controllers in 8xxx GPIO driver
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On Wed, Sep 28, 2011 at 08:52:30PM +0000, Tabi Timur-B04825 wrote:
> On Tue, Sep 27, 2011 at 1:29 PM, Grant Likely <grant.likely@secretlab.ca> wrote:
> 
> > The solution is to make the gpio driver register as a regular
> > interrupt handler, and not as a chained handler.
> 
> I was wondering about that.
> 
> What exactly is a chained handler?  How is it different from a regular handler?

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.

g.