Re: Board level compatibility matching

[Josh Boyer <jwboyer@linux.vnet.ibm.com>]

On Fri, 2008-08-01 at 08:06 -0400, Josh Boyer wrote:
> On Fri, 01 Aug 2008 14:25:39 +1000
> Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote:
> 
> > About this whole generic board mumbo-jumbo: not happening. It's a pipe
> > dream, it doesn't work, and it leads to the sort of mess we have in chrp
> > where we end up having hacks to identify what exact sort of chrp we have
> > and do things differently etc...
> > 
> > NOT HAPPENING.
> > 
> > Now, there are two approaches here that are possible:
> > 
> >  - Your board is really pretty much exactly the same as board XXX,
> > except maybe you have a different flash size or such, and the support
> > for board XXX can cope perfectly with it simply due to the device-tree
> > the right information.
> > 
> > If that happens to be the case, make your board compatible with board
> > XXX. Make that entry -second- in your compatible list, because one day
> > you'll figure out that there -is- indeed a difference and I don't want
> > to see board XXX code start to grow code to recognise your other board
> > and work around the difference. So at that stage, copy board XXX.c file
> > and start over with your own board support that matches on your first
> > compatible propery entry.
> 
> 44x does this today for a small number of boards.  The "issue", if
> there really is one, is that there's no clear definition on what is
> acceptable to be called "compatible".  If _Linux_ platform support for
> board FOO

Ignore that last line.  Emailing before coffee is considered dangerous.

josh