Patch: Defer bus_config_intr() until bus_alloc_resource()..

[Marcel Moolenaar]

On Tue, Jun 01, 2004 at 05:42:57PM -0400, John Baldwin wrote:
> > > > > I need the patch below in order to turn on bus_config_intr() when
> > > > > using the I/O APICs.
*snip*
> > > > I appreciate what you're trying to do but I don't like this approach.
*snip*
> > > Well, arguably it exposes an improper layering violation when
> > > bus_config_intr() was added.
*snip*
> > I still don't like this.
*snip*
> FreeBSD has no format for this and I don't really have time to add multiple 
> resource types (which is what ACPI does, and probably what we will need to do 
> eventually) to struct resource.

Ok, let's relax for a minute. Clearly, the addition of bus_config_intr()
was done in a biggest-bang-for-the-buck approach and I think we can
assume for now that it's there in a way that isn't easily extensible.

So, the root problem now is that we need to consume the ACPI info in
a way that makes it available for later use, i.e., when we actually
allocate the IRQ resource. The solution needs to be simple so that
jhb@ can close the immediate problem and it should also be a step in
the right direction, or at least not a step in the opposite direction,
so that njl@ doesn't get cornered by it at some later time.

Let me give the numbers:
o  We need 2 bits for the polarity,
o  We need 2 bits for the trigger mode,
o  r_flags is 32 bits of which only 16 are in use.

Can we not stick the IRQ properties in r_flags, just like we
stick the alignment properties there, remove bus_config_intr()
and make sure the MD backend queries the flags for polarity and
trigger (0 values will mean "default" and thus preserve backward
compatibility)?

This change should only affect 2 places: the place where we set
the resource and the place where we actually install the interrupt
and its handler. It's roughly in line with what jhb@ wants to achieve
and I think it removes the code that njl@ is objecting to the most,
right?

Oh, and it's not intended to be pretty.

-- 
 Marcel Moolenaar	  USPA: A-39004		 marcel at xcllnt.net