[PATCH libdrm] libdrm_amdgpu: add kernel semaphore support

[Dave Airlie]

On 7 July 2017 at 19:07, Christian König <deathsimple at vodafone.de> wrote:
> Hi Dave,
>
> on first glance that looks rather good to me, but there is one things I
> don't really like and I strongly think Marek will absolutely agree on that:
> When we add a new CS function then let's get ride of all this abstraction!
>
> The new function should get an amdgpu_device_handle and a list of chunks to
> submit, nothing else.
>
> When then provide helper functions to generate the chunks out of the
> existing amdgpu_context_handle and amdgpu_bo_list_handle.
>
> That should be perfectly sufficient and extensible for future additions as
> well.

Sounds tempting, but it a bit messier than it looks once I started
digging into it.

The main things I ran up against is the context sequence mutex protecting the
kernel submissions per context which would be tricky to figure out why that is
required (should we be submitting from different contexts on different threads?)

I'd prefer to land this then refactor a new interface, I do wonder if
maybe Marek
would prefer just doing this all in Mesa and avoiding these APIs a bit more :-)

Once I get the syncobjs in I might look at internally refactoring the
code a bit more,
then a new API.

Dave.