Re: [PATCH v4 0/7] Add dts for mt8183 GPU (and misc panfrost patches)

From: Tomeu Vizoso
Date: Fri Feb 07 2020 - 01:18:06 EST


On 2/7/20 6:26 AM, Nicolas Boichat wrote:
Hi!

Follow-up on the v3: https://patchwork.kernel.org/cover/11331343/.

The main purpose of this series is to upstream the dts change and the
binding document, but I wanted to see how far I could probe the GPU, to
check that the binding is indeed correct. The rest of the patches are
RFC/work-in-progress, but I think some of them could already be picked up.

So this is tested on MT8183 with a chromeos-4.19 kernel, and a ton of
backports to get the latest panfrost driver (I should probably try on
linux-next at some point but this was the path of least resistance).

I tested it as a module as it's more challenging (originally probing would
work built-in, on boot, but not as a module, as I didn't have the power
domain changes, and all power domains are on by default during boot).

Probing logs looks like this, currently. They look sane.
[ 501.319728] panfrost 13040000.gpu: clock rate = 511999970
[ 501.320041] panfrost 13040000.gpu: Linked as a consumer to regulator.14
[ 501.320102] panfrost 13040000.gpu: Linked as a consumer to regulator.31
[ 501.320651] panfrost 13040000.gpu: Linked as a consumer to genpd:0:13040000.gpu
[ 501.320954] panfrost 13040000.gpu: Linked as a consumer to genpd:1:13040000.gpu
[ 501.321062] panfrost 13040000.gpu: Linked as a consumer to genpd:2:13040000.gpu
[ 501.321734] panfrost 13040000.gpu: mali-g72 id 0x6221 major 0x0 minor 0x3 status 0x0
[ 501.321741] panfrost 13040000.gpu: features: 00000000,13de77ff, issues: 00000000,00000400
[ 501.321747] panfrost 13040000.gpu: Features: L2:0x07120206 Shader:0x00000000 Tiler:0x00000809 Mem:0x1 MMU:0x00002830 AS:0xff JS:0x7
[ 501.321752] panfrost 13040000.gpu: shader_present=0x7 l2_present=0x1
[ 501.324951] [drm] Initialized panfrost 1.1.0 20180908 for 13040000.gpu on minor 2

Some more changes are still required to get devfreq working, and of course
I do not have a userspace driver to test this with.

Have you tried the Panfrost tests in IGT? They are atm quite basic, but could be interesting to check that the different HW units are correctly powered on.

Regards,

Tomeu

I believe at least patches 1, 2, and 3 can be merged. 4 and 5 are mostly
useful in conjunction with 6 and 7 (which are not ready yet), so I'll let
maintainers decide.

Thanks!

Nicolas Boichat (7):
dt-bindings: gpu: mali-bifrost: Add Mediatek MT8183
arm64: dts: mt8183: Add node for the Mali GPU
drm/panfrost: Improve error reporting in panfrost_gpu_power_on
drm/panfrost: Add support for multiple regulators
drm/panfrost: Add support for multiple power domains
RFC: drm/panfrost: Add mt8183-mali compatible string
RFC: drm/panfrost: devfreq: Add support for 2 regulators

.../bindings/gpu/arm,mali-bifrost.yaml | 25 ++++
arch/arm64/boot/dts/mediatek/mt8183-evb.dts | 7 +
arch/arm64/boot/dts/mediatek/mt8183.dtsi | 105 +++++++++++++++
drivers/gpu/drm/panfrost/panfrost_devfreq.c | 17 +++
drivers/gpu/drm/panfrost/panfrost_device.c | 123 +++++++++++++++---
drivers/gpu/drm/panfrost/panfrost_device.h | 27 +++-
drivers/gpu/drm/panfrost/panfrost_drv.c | 41 ++++--
drivers/gpu/drm/panfrost/panfrost_gpu.c | 11 +-
8 files changed, 326 insertions(+), 30 deletions(-)