[alsa-devel] [PATCH] of: add empty of_find_node_by_path() for !OF

[Rob Herring]

On Wed, Apr 16, 2014 at 12:15 PM, Mark Brown <broonie at kernel.org> wrote:
> On Wed, Apr 16, 2014 at 11:10:15AM -0500, Rob Herring wrote:
>
>> Yes. If this going to be a common pattern, a
>> of_get_machine_compatible() helper might be useful. Usually, any code
>> searching by path makes me suspicious.
>
> I've always been surprised we don't have more infrastructure for
> quirking off machine type in a similar way to how ACPI systems use DMI.

We used to have machine_is_blah which is kind of replaced by
of_machine_is_compatible, but yes that is a bit limited. What the fsl
ssi driver is doing isn't really a quirk anyway.

PCI also has a whole infrastructure for applying quirks. We could do
something similar which could add/fix properties or do various setup.
Then we'd be able to scatter calls everywhere:

OF_FIXUP("some-compatible-str", fixup_function);

I don't know that we want to encourge that, but would be a way to
separate handling old/broken bindings separately from current code
paths. I guess the question is whether we have many existing cases
(PPC, I'm looking at you) that would benefit.

BTW, I did propose something similar with conditional initcalls a
while back[1]. Perhaps as a fixup would be more acceptable than an
initcall.

Rob

[1] http://comments.gmane.org/gmane.linux.drivers.devicetree/50117