This is my attempt at adding devfreq (and cooling device) support to the lima driver.
I am seeking comments in two general areas: - regarding the integration into the existing lima code - for the actual devfreq code (I had to adapt the panfrost code slightly, because lima uses a bus and a GPU/core clock)
My own TODO list includes "more" testing on various Amlogic SoCs. So far I have tested this on Meson8b and Meson8m2 (which both have a GPU OPP table defined). However, I still need to test this on a GXL board (which is currently missing the GPU OPP table).
Test results from a Meson8m2 board: TEST #1: glmark2-es2-drm --off-screen in an infinite loop while cycling through all available frequencies using the userspace governor
From : To : 182142857 318750000 425000000 510000000 637500000 time(ms) 182142857: 0 1274 1274 1273 1279 5399468 318750000: 1274 0 1274 1273 1272 5114700 425000000: 1276 1274 0 1272 1271 5122008 510000000: 1909 1273 1273 0 636 5274292 * 637500000: 640 1272 1272 1273 0 5186796 Total transition : 24834
TEST #2: glmark2-es2-drm --off-screen in an infinite loop with the simple_ondemand governor From : To : 182142857 318750000 425000000 510000000 637500000 time(ms) 182142857: 0 0 0 0 203 318328 318750000: 53 0 0 0 21 56044 425000000: 27 18 0 0 2 34172 510000000: 27 6 14 0 1 41348 * 637500000: 95 50 33 48 0 2085312
Changes since RFC v1 at [0]: - added lock to protect the statistics as these can be written concurrently for example when the GP and PP IRQ are firing at the same time. Thanks to Qiang Yu for the suggestion! - updated the copyright notice of lima_devfreq.c to indicate that the code is derived from panfrost_devfreq.c. Thanks to Chen-Yu Tsai for the suggestion! - I did not unify the code with panfrost yet because I don't know where to put the result. any suggestion is welcome though!
[0] https://patchwork.freedesktop.org/series/70967/
Martin Blumenstingl (1): drm/lima: Add optional devfreq support
drivers/gpu/drm/lima/Kconfig | 1 + drivers/gpu/drm/lima/Makefile | 3 +- drivers/gpu/drm/lima/lima_devfreq.c | 183 ++++++++++++++++++++++++++++ drivers/gpu/drm/lima/lima_devfreq.h | 15 +++ drivers/gpu/drm/lima/lima_device.c | 4 + drivers/gpu/drm/lima/lima_device.h | 17 +++ drivers/gpu/drm/lima/lima_drv.c | 14 ++- drivers/gpu/drm/lima/lima_sched.c | 7 ++ drivers/gpu/drm/lima/lima_sched.h | 3 + 9 files changed, 244 insertions(+), 3 deletions(-) create mode 100644 drivers/gpu/drm/lima/lima_devfreq.c create mode 100644 drivers/gpu/drm/lima/lima_devfreq.h