From mboxrd@z Thu Jan  1 00:00:00 1970
From: gregory.clement@free-electrons.com (Gregory CLEMENT)
Date: Fri, 10 Jan 2014 21:12:41 +0100
Subject: [PATCH v5 2/4] ARM: mvebu: Add quirk for i2c for the OpenBlocks
 AX3-4 board
In-Reply-To: <20140110200813.GV19878@titan.lakedaemon.net>
References: <1389193589-18485-1-git-send-email-gregory.clement@free-electrons.com>
 <1389193589-18485-3-git-send-email-gregory.clement@free-electrons.com>
 <20140110182240.GK19878@titan.lakedaemon.net>
 <20140110190521.GI18269@obsidianresearch.com>
 <20140110194550.GT19878@titan.lakedaemon.net>
 <20140110200813.GV19878@titan.lakedaemon.net>
Message-ID: <52D05439.7040905@free-electrons.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

Jason,
On 10/01/2014 21:08, Jason Cooper wrote:
> On Fri, Jan 10, 2014 at 02:45:50PM -0500, Jason Cooper wrote:
>> On Fri, Jan 10, 2014 at 12:05:21PM -0700, Jason Gunthorpe wrote:
>>> On Fri, Jan 10, 2014 at 01:22:40PM -0500, Jason Cooper wrote:
>>>
>>>> Do we create new compatible strings to indicate errata, or to indicate
>>>> 'from this version forward there are new features'?  The former would
>>>> indicate as Gregory has written '...-a0-i2c', the latter would warrant
>>>> '...-b0-i2c' and disabling offloading if we don't see '...-b0-i2c'.
>>
>> s/-b0-i2c'./-b0-i2c' or newer./
>>
>>> IMHO the compatible string should represent a specific HW/SW ABI. So
>>> you need a unique compatible string for every variation of that ABI.
>>
>> My concern is that we tend to do things like "marvell,orion-sata" for
>> the first version of the IP block we can work with.  orion5x, kirkwood,
>> dove, and armada 370/xp all use that compatible string to refer to that
>> IP block.
>>
>> Given that we look at it as 'and newer', '...-a0-i2c' would mean no
>> offloading until we introduce '-b0-i2c'.  Or am I mis-understanding what
>> you're saying?
>>
>>> We already have a compatible string defined for the ABI that B0
>>> presents.
>>
>> So 'mv78230-i2c' is newer than 'mv78230-a0-i2c', or are you referring to
>> something else?
> 
> I think the crux of it is:  Is mv78230-i2c the first, or the default?

Here it's clearly the default

Gregory


-- 
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com