R38.2 soc-fan made too much noise

[mingming]

When the machine was turned on, the pwn of the fan was set too high, and the fan made too much noise. The customer requested that it be reduced. Where can the pwm duty cycle be configured

[KevinFFF]

Hi mingming,

Are you using the devkit or custom board for Thor?

Please share the full device tree and dmesg for further check.

[mingming]

hi:

we use custom board.

The device tree and log are attached

hardware/nvidia/t264/nv-public/nv-platform/tegra264-p4071-0000.dtsi

log.txt (87.1 KB)

Only when the device is turned on is the sound very loud. After reaching kenel, this sound can be accepted

[KevinFFF]

@mingming

Only when the device is turned on is the sound very loud.

Could you help to clarify the issue happen in which boot stage? (MB1, MB2, UEFI, Kernel?)
You can simply monitor the noise and check the serial console log at the same time.

[mingming]

hi：

MB1, MB2, UEFI, All three stages are present,do you know how to modify the duty cycle of pwm in the mb1 stage? I can give it a try

[KevinFFF]

Please try to configure the following part in tegra264-mb1-bct-pmic-p3834-xxxx-p4071-xxxx.dtsi for this use case.

				thermal {
					/* Program PWM fan which is cvb-specific */
					block@0 {
						pwm;
						controller-id = <4>; /* PWM4 for soc fan */
						source-frq-hz = <27000000>; /* OSC clock */
						period-ns = <40000>; /* 25 KHz */
						min-microvolts = <0>;
						max-microvolts = <5000000>;
						init-microvolts = <2500000>;
						pwm-clock-enable;
						enable;
					};
				};