From: Arnd Bergmann <arnd@arndb.de>
To: Laura Abbott <laura@labbott.name>, arve@android.com
Cc: Rob Herring <robh+dt@kernel.org>, Frank Rowand <frowand.list@gmail.com>,
        Sumit Semwal <sumit.semwal@linaro.org>,
        Riley Andrews <riandrews@android.com>,
        John Stultz <john.stultz@linaro.org>,
        Grant Likely <grant.likely@linaro.org>, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, Tom Gall <tom.gall@linaro.org>,
        Colin Cross <ccross@google.com>, devel@driverdev.osuosl.org,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>, romlem@google.com,
        mitchelh@codeaurora.org, linux-arm-kernel@lists.infradead.org,
        Feng Tang <feng.tang@intel.com>,
        Marek Szyprowski <m.szyprowski@samsung.com>
Subject: Re: [PATCHv2 0/3] Devicetree bindings for Ion
Date: Tue, 17 Nov 2015 16:15:15 +0100
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On Monday 16 November 2015 16:57:32 Laura Abbott wrote:
> Hi,
> 
> This is another attempt at devicetree bindings for Ion. The big complaint from
> v1 was that too much unnecessary data was being pushed into devicetree.
> v2 takes a different approach of using just compatbile strings for the heaps.
> This gets closer to the devicetree philosophy of describing just the hardware.
> Each heap ultimately represents some kind of memory that exists in the system.
> The compatible string indicates the match for how to handle the type of memory
> on this system. The details like heap-id, name etc. are now pushed out to C
> files. This makes Ion heaps look closer to something like a quirks framework.
> (I'd argue this isn't a complete mischaracterization given the type of setup
> Ion gets used for...) The one downside here is that this leads to more new
> bindings for each board that gets added.
> 
> This version also includes a sample C file which shows what the structure
> might look like. As always, your comments and reviews are appreciated.

I'm still a bit unsure about the concept of hardwiring ion in the DT
bindings. It's not just Linux-specific, it's specific to the implementation
of one or two GPU drivers, and if we fix the bindings for Ion, we might
never be able to migrate them away from this framework.

	Arnd
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