Re: [PATCH] powerpc: consolidate mpc83xx platform files
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Date: 2006-12-12 22:46:41
On Tue, 2006-12-12 at 16:41 -0600, Scott Wood wrote:
Kumar Gala wrote:quoted
On Dec 12, 2006, at 3:30 PM, Scott Wood wrote:quoted
They *may* not want to (and they certainly shouldn't be forced to), but some may not want to define a new ppc_md (or modify a probe function) for every new board if all of the differences are encapsulated in the device tree. I thought one of the main goals of having a device tree is that if it's done right, the kernel need not know about every single model of board, just the different components that a device tree can specify.That's true, and if that's the case you'd just set your "model" to match an existing supported ppc_md.Having an 831x explicitly claim to be an 834x is just a tad icky...
Indeed, but "compatible" doesn't mean exact match and can be a list. In fact, it should probably be the other way around, that is 834x claim to be compatible with 831x... something like: "834x\0831x\083xx" (with appropriate board name appended of course).
And an 83xx-generic machine description does not stop them from doing so. "Generic" does not mean "universal". It means "there's nothing special about this board". If you need board-specific code in the kernel, then don't label it generic.
As long as you are careful enough so that your "generic" ppc_md. doesn't try to match everything with a 83xx in it :-0 Ben.