[PATCH 2/3] [POWERPC][V3] Xilinx: of_serial support for Xilinx uart 16550.

[Josh Boyer]

On Thu, 2008-04-03 at 06:16 +0200, Arnd Bergmann wrote:
> On Thursday 03 April 2008, Grant Likely wrote:
> > >
> > >  Since it is not really compatible with ns16550, shouldn't you at least specify
> > >  a different "compatible" property? That way, the driver won't do incorrect
> > >  accesses when you try to use an old driver with a device tree that specifies
> > >  one of these.
> > 
> > Heh; we've gone back and forth on this issue.  The problem is that we
> > have a common case of ns16550 like devices that require a little bit
> > of register address tweaking that spans a whole range of vendors (so
> > adding a compatible match with each of those vendor's prefixes is
> > probably non-scalable).  So, if "ns16550" is not a good idea, then
> > what should be used?  "sparse16550" has been suggested more than once.
> 
> After another IRC discussion between Grant, Segher and myself, we concluded
> that we don't need to invent a new "compatible" value, as only new device
> trees with old kernels will have a problem with this, and they don't work
> in the first place.
> 
> The devices will still have their specific "compatible" value, e.g.
> "xlnx,plb-uart16550-1.00.c", followed by "ns16550", and possibly
> "ns16450" and "i8250", although the last two do not have an effect
> on Linux.
> 
> Josh, can you please forward all three patches in their latest version?
> 
> Acked-by: Arnd Bergmann <arnd at arndb.de>

So is the discussion on reg-offset settled then?  It seemed Paul and
David had some issues with that, and I'd like to make sure everyone is
agreed on that before I bring in patches 2 and 3.

josh