On Mon, Feb 3, 2014 at 11:16 AM, Dmitry Eremin-Solenikov dbaryshkov@gmail.com wrote:
Hello,
On Mon, Feb 3, 2014 at 7:49 PM, Rob Clark robdclark@gmail.com wrote:
On Sun, Feb 2, 2014 at 6:50 PM, Dmitry Eremin-Solenikov dbaryshkov@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?
ttm can definitely handle it. Take a look at the mgag200 or cirrus drivers for relatively simple hardware/drivers that use ttm.
Alex