Re: [RFC] [PATCH] Device Tree on ARM platform

Mark Brown
2009-05-27T16:32:47Z

On Wed, May 27, 2009 at 05:05:27PM +0200, Robert Schwebel wrote:

> I'm highly convinced that the existence of oftree-hell in ARM-land would
> have been *the* key motivation for FSL to have worked on mainline
> instead of inhouse-BSPs back in 2004 when we mainlined i.MX1 and in 2007
> when we started the mainline work on MX27 and MX31.

I remain to be convinced about that but anyway..

> Seriously: oftree in general is a good idea. Just that it doesn't work
> in practise. The concept has some serious flaws:

> - Platform data makes it possible to store function pointers. There
> is no equivalent to this concept in oftree-land.

The handling of platform data is my main concern as someone working
primarily on platform independant drivers - function pointers are a
particular problem but the possibility of having to write code to
handle both OF and non-OF systems to cater for systems using both
approaches is also a concern for me.

> oftree could be a great tool if these things would be resolved.
> Currently they are not, and in result, ARM just works and is easy,
> whereas on PowerPC systems people often spend more time working on
> binding stuff than on the actual functionality.

This worries me too, my experiences with OF device tree handling for
ASoC have been pretty negative - but then audio is one of the worst
cases for handling within the device tree.