Re: [PATCH 0/9] TI DMM-TILER driver

Dave Airlie
2010-12-16T23:28:11Z

On Fri, Dec 17, 2010 at 5:02 AM, David Sin <davidsin@ti.com> wrote:
> On Thu, Dec 16, 2010 at 06:43:48PM +0100, Arnd Bergmann wrote:
>> As far as I can tell, both DMM and GEM at a high level manage objects
>> in video memory. The IOMMU that you have on the Omap hardware seems
>> to resemble the GART that sits between PC-style video cards and main
>> memory.
>>
>> I don't know any details, but google quickly finds
>> http://lwn.net/Articles/283798/ with a description of the
>> initial GEM design. My main thought when looking over the
>> DMM code was that this should not be tied too closely to a
>> specific hardware, and GEM seems to be an existing abstraction
>> that may fit what you need.
>>
>>       Arnd
> Thanks for the pointer, Arnd.  I also found a nice readme file in
> the gpu/drm directory, which points to a wiki and source code.
> I'll read into this and get back to you.

I get the impression with the ARM graphics, that you just have a lot
of separate drivers for separate IP blocks all providing some misc
random interfaces to userspace where some binary driver binds all the
functionality together into a useful whole, which seems like a really
bad design.

Generally on x86, the tiling hw is part of the GPU and is exposed as
part of a coherent GPU driver.

I'm just wonder what the use-cases for this tiler are and what open
apps can use it for?

Dave.