[RFC/PATCH 4/4] Add support for MSI on Axon-based Cell systems

[Arnd Bergmann]

On Tuesday 05 June 2007, Jean-Christophe Dubois wrote:
> On Monday 04 June 2007 15:00:05 Michael Ellerman wrote:
> > +       pr_debug("axon_msi: initialising ...\n");
> > +
> > +       for_each_compatible_node(node, NULL, "ibm,axon-msic") {
> > +               if (axon_msi_setup_one(of_node_get(node)) == 0)
> > +                       found++;
> > +       }
> > +       of_node_put(node);
> 
> 2 comments:
> 
> 1) There is no "ibm,axon-msic" compatible property in the SLOF tree provided 
> by IBM on the CAB (or other such platforms). Therefore this code will not 
> work on these platforms.

Right, the firmware needs to support msi so we can use it. I guess taht's true
for every device: If the firmware decies to hide it from us, we better don't
try to touch it.

> 2) you should somehow check for the Axon version. Axon 1.1 (and prior) are 
> know to be loosing MSI/MBX interrupts (but not the data part associated to 
> them). Therefore this should be enabled only on Axon 2.1 (or later).

Good point, thanks for mentioning it. Christian, can you confirm that the
ibm,axon-msic node is only created on systems with axon 2.1 or later?

	Arnd <><