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

[M. Warner Losh]

In message: <20040601221109.GA21063 at ns1.xcllnt.net>
            Marcel Moolenaar <marcel at xcllnt.net> writes:
: 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.

I like it.  Or should I say "Given that we're looking for an
evolutionary change to shoe horn this in, I think it is better than
any of the other ugly kludges."

Warner