Selecting memory manager for embedded DRM device

[Dmitry Eremin-Solenikov]

Hello,

On Mon, Feb 3, 2014 at 7:49 PM, Rob Clark <robdclark at gmail.com> wrote:
> On Sun, Feb 2, 2014 at 6:50 PM, Dmitry Eremin-Solenikov
> <dbaryshkov at gmail.com> wrote:
>> Hello,
>>
>> I'm looking onto writing DRM/KMS drivers for few pieces of
>> embedded equipment. I stumbled upon selecting GEM/TTM/whatever
>> for them. Could you please guide me?
>
> The common choices are either:
>
>   * TTM + GEM userspace interface (nouveau and radeon)
>   * or just GEM (intel, and most of the ARM devices)
>
> TTM seems to be mostly advantageous if you need to manage migration
> between VRAM / GART / system RAM.  But it sounds like you are talking
> about a UMA system, so maybe TTM doesn't help you as much.

Thank you for the answer. Indeed I had the feeling that just GEM would be
work for UMA devices. I'm interested about the driver for my second hardware.
It's a separate graphics chip with separate VRAM, no access to system
memory and nearly no advanced capabilities (few 2D accelerations,
but nothing fancy). Would that require TTM, some special setup of GEM
or something completely different?


-- 
With best wishes
Dmitry