Handling multiple GPIO controllers in 8xxx GPIO driver

Tabi Timur-B04825 B04825 at freescale.com
Fri Sep 30 06:22:06 EST 2011

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 
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 
any descriptions of it.

Timur Tabi
Linux kernel developer at Freescale

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