Re: [PATCH 0/5] Meson (32-bit): add support for the Mali GPU

[Neil Armstrong]

On 08/12/2018 18:12, Martin Blumenstingl wrote:
> This series adds support for the Mali-450 GPU on Meson8 and Meson8b.
> Meson6 uses a Mali-400 GPU but since we don't have a clock driver (and
> I don't have a device for testing) Meson6 is left out in this series.
> 
> Meson8 uses a Mali-450 MP6 with six pixel processors. Meson8b (as
> cost-reduced SoC) uses a Mali-450 MP2 with two pixel processors.
> I tested both using the open source lima driver and a patched mesa
> from the lima project as well. Since we don't have display support
> on the 32-bit SoCs I used off-screen rendering as described in [0].
> The result is (for example): [1]
> 
> The bootloader (at least on my boards) leaves the Mali clock disabled
> by default. The board crashes when trying to access the Mali registers
> with the "core" clock disabled.
> Thus this series also implements the required clock driver changes. The
> Mali clock tree on Meson8b and Meson8m2 is almost identical to the one
> on GXBB (see the description of patch #3 for more details). Only Meson8
> is slightly different as it doesn't have a glitch-free mux. Patch #2
> prepares the meson8b clock driver so we can have different clocks per
> SoC.
> 
> Dependencies:
> - the .dts changes depend on my other series "ARM: dts: meson: add the
>   APB/APB2 busses" from [2]
> - the .dts changes from this series have no compile-time dependency on
>   the clock driver changes because CLKID_MALI was defined in the
>   dt-bindings since the first version of the clock driver (but it was
>   not used until now).
> - the .dts changes from this series have a runtime dependency on the
>   clock driver changes (also from this series) if you have a kernel
>   patched with the lima driver (without the lima driver there's no
>   runtime dependency)
> 
> Other notes:
> By default the GPU runs off the XTAL clock (24MHz). The lima driver
> currently does not update the GPU clock rate. Different frequencies
> have to be requested by adding the following properties to the Mali
> GPU node (to run it at 510MHz for example):
>   assigned-clocks = <&clkc CLKID_MALI>;
>   assigned-clock-rates = <510000000>;
> 
> 
> [0] https://gitlab.freedesktop.org/lima/web/wikis/home
> [1] https://abload.de/img/dump0myic0.png
> [2] https://patchwork.kernel.org/cover/10719445/
> 
> 
> Martin Blumenstingl (5):
>   dt-bindings: gpu: mali-utgard: add Amlogic Meson8 and Meson8b
>     compatible
>   clk: meson: meson8b: use a separate clock table for Meson8
>   clk: meson: meson8b: add the GPU clock tree
>   ARM: dts: meson8: add the Mali-450 MP6 GPU
>   ARM: dts: meson8b: add the Mali-450 MP2 GPU
> 
>  .../bindings/gpu/arm,mali-utgard.txt          |   6 +
>  arch/arm/boot/dts/meson8.dtsi                 |  58 +++
>  arch/arm/boot/dts/meson8b.dtsi                |  46 +++
>  drivers/clk/meson/meson8b.c                   | 349 +++++++++++++++++-
>  drivers/clk/meson/meson8b.h                   |   9 +-
>  5 files changed, 461 insertions(+), 7 deletions(-)
> 

Applied patches 2 & 3 to next/drivers for Linux 5.1

Kevin, have fun with the other patches !

Neil