[PATCHv2 0/3] Devicetree bindings for Ion

Arnd Bergmann arnd at arndb.de
Tue Nov 17 07:15:15 PST 2015

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.


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