Re: [PATCH v2 03/14] drm/msm/a6xx: Introduce GMU wrapper support

From: Dmitry Baryshkov
Date: Fri Feb 17 2023 - 16:44:11 EST


On 17/02/2023 23:41, Konrad Dybcio wrote:


On 17.02.2023 22:37, Dmitry Baryshkov wrote:
On 14/02/2023 19:31, Konrad Dybcio wrote:
Some (particularly SMD_RPM, a.k.a non-RPMh) SoCs implement A6XX GPUs
but don't implement the associated GMUs. This is due to the fact that
the GMU directly pokes at RPMh. Sadly, this means we have to take care
of enabling & scaling power rails, clocks and bandwidth ourselves.

Reuse existing Adreno-common code and modify the deeply-GMU-infused
A6XX code to facilitate these GPUs. This involves if-ing out lots
of GMU callbacks and introducing a new type of GMU - GMU wrapper.
This is essentially a register region which is convenient to model
as a device. We'll use it for managing the GDSCs.

Why do you call it a wrapper?
That's what Qualcomm calls it.. The GMU-less GPUs have (almost) all the
same GMU GX/CX registers as the real GMUs in this 'wrapper' region, so
that lets us reuse some code with gmu_(read/write/rmw) calls.


Ack. If you can add this to the commit message, it would be great.

--
With best wishes
Dmitry