Subject: Re: common irq handler code
To: None <port-arm@netbsd.org>
From: Toru Nishimura <locore64@alkyltechnology.com>
List: port-arm
Date: 04/09/2007 16:01:56
Chris Gilbert says;

[ ... proposal to add "common irq code path" ... ]

> So instead I've taken the footbridge irqhandler code, and made it a
> common file. (The footbridge version was based on Jason's work for
> xscale platforms)

I agree with that providing "the common" is an better idea, but it should
be emphasised that it has limitations which might be inadequate for some
cases.

There are two different kinds of "common code"; one to ease future
growth and another to spoil the growth.  As Chris points there is the
number of IRQ designs in ARM implementation.  Having separate intr*.c
code is the way to ease the new HW adaptation; just to copy the most
similar intr*.c as a template and hack the copy at well until it works.  Then,
the "common" should be regarded "not-generic-but-useful-for-simple-case"
code, not to impose the adaptation for the possible new (increasingly
getting complicated) ARM HW.

Toru Nishimura/ALKYL Technology