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| author | Mikhail Kshevetskiy <mikhail.kshevetskiy@iopsys.eu> | 2025-09-30 05:16:56 +0300 |
|---|---|---|
| committer | AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> | 2025-10-13 12:42:17 +0300 |
| commit | 8365a3e1fdc3e9a69114165877e0ca281ffdc8de (patch) | |
| tree | b6a7f619a3dd33eb590853a1742b56e2606ec0e6 /tools/lib/python | |
| parent | bbfb1118fe0e913cfdf49b5c2989cadc39b06781 (diff) | |
| download | linux-8365a3e1fdc3e9a69114165877e0ca281ffdc8de.tar.xz | |
arm64: dts: mediatek: mt7986-bpi-r3: Change fan PWM value for mid speed
Popular cheap PWM fans for this machine, like the ones coming in
heatsink+fan combos will not work properly at the currently defined
medium speed. Trying different pwm setting using a command
echo $value > /sys/devices/platform/pwm-fan/hwmon/hwmon1/pwm1
I found:
pwm1 value fan rotation speed cpu temperature notes
-----------------------------------------------------------------
0 maximal 31.5 Celsius too noisy
40 optimal 35.2 Celsius no noise hearable
95 minimal
above 95 does not rotate 55.5 Celsius
-----------------------------------------------------------------
Thus only cpu-active-high and cpu-active-low modes are usable.
I think this is wrong.
This patch fixes cpu-active-medium settings for bpi-r3 board.
I know, the patch is not ideal as it can break pwm fan for some users.
Likely this is the only official mt7986-bpi-r3 heatsink+fan solution
available on the market.
This patch may not be enough. Users may wants to tweak their thermal_zone0
trip points, thus tuning fan rotation speed depending on cpu temperature.
That can be done on the base of the following example:
=== example =========
# cpu temperature below 25 Celsius degrees, no rotation
echo 25000 > /sys/class/thermal/thermal_zone0/trip_point_4_temp
# cpu temperature in [25..32] Celsius degrees, normal rotation speed
echo 32000 > /sys/class/thermal/thermal_zone0/trip_point_3_temp
# cpu temperature above 50 Celsius degrees, max rotation speed
echo 50000 > /sys/class/thermal/thermal_zone0/trip_point_2_temp
=====================
Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy@iopsys.eu>
Acked-by: Frank Wunderlich <frank-w@public-files.de>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Diffstat (limited to 'tools/lib/python')
0 files changed, 0 insertions, 0 deletions