linux-kernel - [PATCH 0/4] drm/panfrost: Turn off clocks and regulators in PM

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Message-ID: <20231030132257.85379-1-angelogioacchino.delregno@collabora.com>
Date:   Mon, 30 Oct 2023 14:22:53 +0100
From:   AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@...labora.com>
To:     boris.brezillon@...labora.com
Cc:     robh@...nel.org, steven.price@....com,
        maarten.lankhorst@...ux.intel.com, mripard@...nel.org,
        tzimmermann@...e.de, airlied@...il.com, daniel@...ll.ch,
        dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org,
        wenst@...omium.org,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@...labora.com>, kernel@...labora.com
Subject: [PATCH 0/4] drm/panfrost: Turn off clocks and regulators in PM

At least MediaTek platforms are able to get the GPU clocks and regulators
completely off during system suspend, allowing to save a bit of power.

Panfrost is used on more than just MediaTek SoCs and the benefits of this
can be variable across different SoC models and/or different SoCs from
different manufacturers: this means that just adding this ability for all
could result in unexpected issues and breakages on untested SoCs.

For the aforemenetioned reasons, turning off the clocks and/or regulators
was implemented inside of a capabilities barrier that shall be enabled on
a per-SoC basis (in the panfrost_compatible platform data) after testing
of both benefits and feasibility.

In this series, I am adding the ability to switch on/off clocks and
regulators and enabling that on all MediaTek platforms, as I was able
to successfully test that on multiple Chromebooks featuring different
MediaTek SoCs; specifically, I've manually tested on MT8186, MT8192 and
MT8195, while MT8183 got tested only by KernelCI.

Cheers!

AngeloGioacchino Del Regno (4):
  drm/panfrost: Implement ability to turn on/off GPU clocks in suspend
  drm/panfrost: Set clocks on/off during system sleep on MediaTek SoCs
  drm/panfrost: Implement ability to turn on/off regulators in suspend
  drm/panfrost: Set regulators on/off during system sleep on MediaTek
    SoCs

 drivers/gpu/drm/panfrost/panfrost_device.c | 78 ++++++++++++++++++++--
 drivers/gpu/drm/panfrost/panfrost_device.h | 13 ++++
 drivers/gpu/drm/panfrost/panfrost_drv.c    |  3 +
 3 files changed, 90 insertions(+), 4 deletions(-)

-- 
2.42.0