Power Management for Raspberry Pi V3D GPU
From: | Maíra Canal <mcanal-AT-igalia.com> | |
To: | Michael Turquette <mturquette-AT-baylibre.com>, Stephen Boyd <sboyd-AT-kernel.org>, Nicolas Saenz Julienne <nsaenz-AT-kernel.org>, Florian Fainelli <florian.fainelli-AT-broadcom.com>, Stefan Wahren <wahrenst-AT-gmx.net>, Maxime Ripard <mripard-AT-kernel.org>, Melissa Wen <mwen-AT-igalia.com>, Iago Toral Quiroga <itoral-AT-igalia.com>, Dom Cobley <popcornmix-AT-gmail.com>, Dave Stevenson <dave.stevenson-AT-raspberrypi.com>, Philipp Zabel <p.zabel-AT-pengutronix.de> | |
Subject: | [PATCH v2 0/5] Power Management for Raspberry Pi V3D GPU | |
Date: | Thu, 31 Jul 2025 18:06:16 -0300 | |
Message-ID: | <20250731-v3d-power-management-v2-0-032d56b01964@igalia.com> | |
Cc: | linux-clk-AT-vger.kernel.org, linux-rpi-kernel-AT-lists.infradead.org, linux-arm-kernel-AT-lists.infradead.org, dri-devel-AT-lists.freedesktop.org, Broadcom internal kernel review list <bcm-kernel-feedback-list-AT-broadcom.com>, kernel-dev-AT-igalia.com, Maíra Canal <mcanal-AT-igalia.com> | |
Archive-link: | Article |
This series introduces Runtime PM for Raspberry Pi's GPU, V3D. Currently, the GPU clock stays up during the whole operation, even if the GPU is idle. By introducing Runtime PM, we can now turn off the clock completely during idle. For example, with this series, when checking `vcgencmd measure_clock v3d` in the Raspberry Pi 5, we get: (idle) $ vcgencmd measure_clock v3d frequency(0)=0 (running glmark2) $ vcgencmd measure_clock v3d frequency(0)=960016128 To implement PM for V3D, it was needed to add a prepare and unprepare hook to RPi's firmware clocks. Currently, they don't turn on and off, nor lower the clock rate. Therefore, PATCH 2/5 addresses this issue in clk/bcm/clk-raspberrypi.c. Apart from the first patch, the last three patches are related to PM enablement in the V3D driver. To ease testing in Raspberry Pi 4 and 5, I prepared a downstream branch backporting this series to rpi-6.12.y [1]. [1] https://github.com/mairacanal/linux-rpi/tree/v3d/downstre... Best Regards, - Maíra --- v1 -> v2: https://lore.kernel.org/r/20250728-v3d-power-management-v... - [1/5] NEW PATCH: "clk: bcm: rpi: Add missing logs if firmware fails" (Stefan Wahren) - [2/5] Remove the "Fixes:" tag (Stefan Wahren) - [2/5] dev_err_ratelimited() instead of dev_err() (Stefan Wahren) - [2/5] Instead of logging the clock ID, use clk_hw_get_name(hw) to log the name (Stefan Wahren) - [2/5] Add a newline character at the end of the log message (Stefan Wahren) - [2/5] Use CLK_IS_CRITICAL for all clocks that can't be disabled (Maxime Ripard) - [3/5] NEW PATCH: "clk: bcm: rpi: Maximize V3D clock" - [4/5] Use devm_reset_control_get_optional_exclusive() (Philipp Zabel) - [4/5] Make sure that resource are cleaned in the inverse order of allocation (Philipp Zabel) --- Maíra Canal (4): clk: bcm: rpi: Turn firmware clock on/off when preparing/unpreparing clk: bcm: rpi: Maximize V3D clock drm/v3d: Allocate all resources before enabling the clock drm/v3d: Introduce Runtime Power Management Stefan Wahren (1): clk: bcm: rpi: Add missing logs if firmware fails drivers/clk/bcm/clk-raspberrypi.c | 72 ++++++++++++++++- drivers/gpu/drm/v3d/Makefile | 3 +- drivers/gpu/drm/v3d/v3d_debugfs.c | 23 +++++- drivers/gpu/drm/v3d/v3d_drv.c | 160 ++++++++++++++++++-------------------- drivers/gpu/drm/v3d/v3d_drv.h | 21 ++++- drivers/gpu/drm/v3d/v3d_gem.c | 18 ++++- drivers/gpu/drm/v3d/v3d_irq.c | 15 ++-- drivers/gpu/drm/v3d/v3d_mmu.c | 12 ++- drivers/gpu/drm/v3d/v3d_power.c | 79 +++++++++++++++++++ drivers/gpu/drm/v3d/v3d_submit.c | 19 ++++- 10 files changed, 311 insertions(+), 111 deletions(-) --- base-commit: 518867b09394217d13f6e05f704450bd9d2c8eeb change-id: 20250728-v3d-power-management-eebb2024dc96