Re: [PATCH v3 00/25] irq_domain generalization and refinement

On Sat, Feb 04, 2012 at 10:17:48PM +0000, Russell King - ARM Linux wrote:

On Fri, Jan 27, 2012 at 02:35:54PM -0700, Grant Likely wrote:

quoted

Hey everyone,

This patch series is ready for much wider consumption now.  I'd like
to get it into linux-next ASAP because there will be ARM board support
depending on it.  I'll wait a few days before I ask Stephen to pull
this in.

Grant,

Can you answer me this: does this irqdomain support require DT?

No, it should not.  Any situation where it does is a bug.

Now, here's the thing: I believe that IRQ domains - at least as far as
the hwirq stuff - should be available irrespective of whether we have
the rest of the IRQ domain support code in place, so that IRQ support
code doesn't have to keep playing games to decode from the global
space to the per-controller number space.

Correct.  That's the intent.  My new series flushes out irq_domain quite a
bit better and gets all architectures doing the same thing if they use
irq_domains.  I've done some testing on both CONFIG_OF and !CONFIG_OF builds,
but I'm going to do some more to make sure I've not missed anything.

I believe that would certainly help the current OMAP problems, where
the current lack of CONFIG_IRQ_DOMAIN basically makes the kernel oops
on boot.

How we fix this regression for 3.4 I've no idea at present, I'm trying
to work out what the real dependencies are for OMAP on this stuff.

Finally, do we need asm/irq.h in our asm/prom.h ?  That's causing
fragility between DT and non-DT builds, because people are finding
that their DT builds work without their mach/irqs.h includes but
fail when built with non-DT.  The only thing which DT might need -
at the most - is NR_IRQS, but I'd hope with things like irq domains
it doesn't actually require it.

I don't think so.  There may be a file or two that break because they're
not including everything they need, but I don't think anything in the
header requires it.

The irq_domain code is well isolated.  The header file doesn't need to
be including it.

g.