1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
|
From 863dace20e48954a7e013a2e88e27c692ce165b0 Mon Sep 17 00:00:00 2001
From: Nick B <nick@pelagiris.org>
Date: Mon, 9 Mar 2020 09:05:39 -0400
Subject: [PATCH] Reduce noise from rpi poe hat fan
This adds 2 extra states, at 40c and 45c, with PWM of 31 and 63 (out
of 255) for the rpi poe hat fan. This significantly improves user
experience by providing a smoother ramp up of the fan, from a pwm 0
to 31 to 63 then finally to 150, and additionally makes it very easy
for users to further tweak the values as needed for their specific
application.
The possible concerns I have are that a hysteresis of 2000 (2c) could
be too narrow, and that running the fan more at a reduced temperature
(40000 - 40c) could cause problems.
Signed-off-by: Nick B <nick@pelagiris.org>
---
.../arm/boot/dts/overlays/rpi-poe-overlay.dts | 35 ++++++++++++++++---
1 file changed, 30 insertions(+), 5 deletions(-)
--- a/arch/arm/boot/dts/overlays/rpi-poe-overlay.dts
+++ b/arch/arm/boot/dts/overlays/rpi-poe-overlay.dts
@@ -14,9 +14,9 @@
compatible = "raspberrypi,rpi-poe-fan";
firmware = <&firmware>;
cooling-min-state = <0>;
- cooling-max-state = <2>;
+ cooling-max-state = <4>;
#cooling-cells = <2>;
- cooling-levels = <0 150 255>;
+ cooling-levels = <0 31 63 150 255>;
status = "okay";
};
};
@@ -27,12 +27,21 @@
__overlay__ {
trips {
trip0: trip0 {
- temperature = <50000>;
- hysteresis = <5000>;
+ temperature = <40000>;
+ hysteresis = <2000>;
type = "active";
};
trip1: trip1 {
-
+ temperature = <45000>;
+ hysteresis = <2000>;
+ type = "active";
+ };
+ trip2: trip2 {
+ temperature = <50000>;
+ hysteresis = <2000>;
+ type = "active";
+ };
+ trip3: trip3 {
temperature = <55000>;
hysteresis = <5000>;
type = "active";
@@ -47,6 +56,14 @@
trip = <&trip1>;
cooling-device = <&fan0 1 2>;
};
+ map2 {
+ trip = <&trip2>;
+ cooling-device = <&fan0 2 3>;
+ };
+ map3 {
+ trip = <&trip3>;
+ cooling-device = <&fan0 3 4>;
+ };
};
};
};
@@ -58,6 +75,10 @@
poe_fan_temp0_hyst = <&trip0>,"hysteresis:0";
poe_fan_temp1 = <&trip1>,"temperature:0";
poe_fan_temp1_hyst = <&trip1>,"hysteresis:0";
+ poe_fan_temp2 = <&trip2>,"temperature:0";
+ poe_fan_temp2_hyst = <&trip2>,"hysteresis:0";
+ poe_fan_temp3 = <&trip3>,"temperature:0";
+ poe_fan_temp3_hyst = <&trip3>,"hysteresis:0";
};
};
@@ -66,5 +87,9 @@
poe_fan_temp0_hyst = <&trip0>,"hysteresis:0";
poe_fan_temp1 = <&trip1>,"temperature:0";
poe_fan_temp1_hyst = <&trip1>,"hysteresis:0";
+ poe_fan_temp2 = <&trip2>,"temperature:0";
+ poe_fan_temp2_hyst = <&trip2>,"hysteresis:0";
+ poe_fan_temp3 = <&trip3>,"temperature:0";
+ poe_fan_temp3_hyst = <&trip3>,"hysteresis:0";
};
};
|
