From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from py-out-1112.google.com (py-out-1112.google.com [64.233.166.180]) by ozlabs.org (Postfix) with ESMTP id 4E4D5DDE00 for ; Sun, 6 Apr 2008 01:46:05 +1100 (EST) Received: by py-out-1112.google.com with SMTP id z59so598720pyg.27 for ; Sat, 05 Apr 2008 07:46:04 -0700 (PDT) Subject: Re: [PATCH 2/3] [POWERPC][V3] Xilinx: of_serial support for Xilinx uart 16550. From: Josh Boyer To: Arnd Bergmann In-Reply-To: <200804030616.09825.arnd@arndb.de> References: <20080402232213.5D87515B8067@mail37-sin.bigfish.com> <200804030134.11437.arnd@arndb.de> <200804030616.09825.arnd@arndb.de> Content-Type: text/plain Date: Sat, 05 Apr 2008 09:45:56 -0500 Message-Id: <1207406756.6809.2.camel@vader.jdub.homelinux.org> Mime-Version: 1.0 Cc: linuxppc-dev@ozlabs.org, paulus@samba.org, John Linn , david@gibson.dropbear.id.au List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 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