Re: Board level compatibility matching

On Fri, 2008-08-01 at 08:06 -0400, Josh Boyer wrote:

On Fri, 01 Aug 2008 14:25:39 +1000
Benjamin Herrenschmidt [off-list ref] wrote:

quoted

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