我正在调试 pwmtachtool<->hwmon 交互问题，当 OpenBMC 映像在连接到 SensorsBoard 和风扇（主机未连接）的 AST2600 EVB 上运行时观察到。正在运行的 OpenBMC 映像是使用 bitbake 构建的，它包括为这个 SensorBoard 定制的 recipes-phosphor/configuration/entity-manager/SensorBoard.json。已验证 SensorsBoard 上的 I2C 传感器可通过 i2ctools 访问，并按预期运行。但是，运行“pwmtachtool <dev_id> --get-fan-speed <fan_num>”始终报告“风扇速度为 0”，即使 phy 风扇已正确连接。例如：
/usr/local/bin/pwmtachtool 0 --get-fan-speed 0 --verbose
GET_TACH_SPEED：转速值 0
风扇 0 速度为 0
猫 /sys/class/hwmon/hwmon0/fan0_input
0
仔细查看 pwmtachtool 代码路径，我看到它调用了 pwmtach_action()，它读取“/sys/class/hwmon/hwmon<dev_id>/fan”，它始终为 0。尝试了所有 <dev_id>/ 组合，由sysfs：同样的结果。到目前为止，无法弄清楚为什么会这样。我非常感谢所有有关如何调试此问题的建议。
额外细节：
ll /sys/类/hwmon/
lrwxrwxrwx 1 root root 0 Feb 16 08:52 hwmon0 -> ../../devices/platform/ahb/ahb:apb/1e610000.pwm-tacho-controller/hwmon/hwmon0
lrwxrwxrwx 1 根 0 Feb 16 08:52 hwmon1 -> ../../devices/platform/iio-hwmon/hwmon/hwmon1
lrwxrwxrwx 1 root root 0 Feb 26 22:20 hwmon2 -> ../../devices/platform/ahb/ahb:apb/ahb:apb:bus@1e78a000/1e78a480.i2c-bus/i2c-8/8-004d /hwmon/hwmon2
ll /sys/class/hwmon/hwmon0/*
lrwxrwxrwx 1 root root 0 Feb 26 22:20 /sys/class/hwmon/hwmon0/device -> ../../../1e610000.pwm-tacho-controller
-r--r--r-- 1 root root 4096 Feb 26 22:20 /sys/class/hwmon/hwmon0/fan0_input
-r--r--r-- 1 root root 4096 Feb 26 22:20 /sys/class/hwmon/hwmon0/fan10_input
-r--r--r-- 1 root root 4096 Feb 26 22:20 /sys/class/hwmon/hwmon0/fan11_input
-r--r--r-- 1 root root 4096 Feb 26 22:20 /sys/class/hwmon/hwmon0/fan12_input
-r--r--r-- 1 root root 4096 Feb 26 22:20 /sys/class/hwmon/hwmon0/fan13_input
-r--r--r-- 1 root root 4096 Feb 26 22:20 /sys/class/hwmon/hwmon0/fan14_input
-r--r--r-- 1 root root 4096 Feb 26 22:20 /sys/class/hwmon/hwmon0/fan15_input
-r--r--r-- 1 root root 4096 Feb 26 22:20 /sys/class/hwmon/hwmon0/fan1_input
-r--r--r-- 1 root root 4096 Feb 26 22:20 /sys/class/hwmon/hwmon0/fan2_input
-r--r--r-- 1 root root 4096 Feb 26 22:20 /sys/class/hwmon/hwmon0/fan3_input
-r--r--r-- 1 root root 4096 Feb 26 22:20 /sys/class/hwmon/hwmon0/fan4_input
-r--r--r-- 1 root root 4096 Feb 26 22:20 /sys/class/hwmon/hwmon0/fan5_input
-r--r--r-- 1 root root 4096 Feb 26 22:20 /sys/class/hwmon/hwmon0/fan6_input
-r--r--r-- 1 root root 4096 Feb 26 22:20 /sys/class/hwmon/hwmon0/fan7_input
-r--r--r-- 1 root root 4096 Feb 26 22:20 /sys/class/hwmon/hwmon0/fan8_input
-r--r--r-- 1 root root 4096 Feb 26 22:20 /sys/class/hwmon/hwmon0/fan9_input
-r--r--r-- 1 root root 4096 Feb 26 22:20 /sys/class/hwmon/hwmon0/name
lrwxrwxrwx 1 root root 0 Feb 26 22:20 /sys/class/hwmon/hwmon0/of_node -> ../../../../../../../firmware/devicetree/base/ahb /apb/pwm-tacho-controller@1e610000
-rw-r--r-- 1 root root 4096 Feb 26 22:20 /sys/class/hwmon/hwmon0/pwm0
-rw-r--r-- 1 root root 4096 Feb 26 22:20 /sys/class/hwmon/hwmon0/pwm1
-rw-r--r-- 1 root root 4096 Feb 26 22:20 /sys/class/hwmon/hwmon0/pwm10
-rw-r--r-- 1 root root 4096 Feb 26 22:20 /sys/class/hwmon/hwmon0/pwm11
-rw-r--r-- 1 root root 4096 Feb 26 22:20 /sys/class/hwmon/hwmon0/pwm12
-rw-r--r-- 1 root root 4096 Feb 26 22:20 /sys/class/hwmon/hwmon0/pwm13
-rw-r--r-- 1 root root 4096 Feb 26 22:20 /sys/class/hwmon/hwmon0/pwm14
-rw-r--r-- 1 root root 4096 Feb 26 22:20 /sys/class/hwmon/hwmon0/pwm15
-rw-r--r-- 1 root root 4096 Feb 26 22:20 /sys/class/hwmon/hwmon0/pwm2
-rw-r--r-- 1 root root 4096 Feb 26 22:20 /sys/class/hwmon/hwmon0/pwm3
-rw-r--r-- 1 root root 4096 Feb 26 22:20 /sys/class/hwmon/hwmon0/pwm4
-rw-r--r-- 1 root root 4096 Feb 26 22:20 /sys/class/hwmon/hwmon0/pwm5
-rw-r--r-- 1 root root 4096 Feb 26 22:20 /sys/class/hwmon/hwmon0/pwm6
-rw-r--r-- 1 root root 4096 Feb 26 22:20 /sys/class/hwmon/hwmon0/pwm7
-rw-r--r-- 1 root root 4096 Feb 26 22:20 /sys/class/hwmon/hwmon0/pwm8
-rw-r--r-- 1 root root 4096 Feb 26 22:20 /sys/class/hwmon/hwmon0/pwm9
lrwxrwxrwx 1 root root 0 Feb 16 08:52 /sys/class/hwmon/hwmon0/subsystem -> ../../../../../../../class/hwmon
-rw-r--r-- 1 root root 4096 Feb 16 08:52 /sys/class/hwmon/hwmon0/uevent