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

[Nate Lawson]

On Tue, 1 Jun 2004, Marcel Moolenaar wrote:
> 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.

Yes, exactly.

> 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?

This is an excellent idea.

-Nate