The System Fails to Be Suspended Because the AI Application Process Does Not Exit

Symptom

Failed to enter the suspension mode.

According to the application logs, hwts, the task distribution module, is busy, and it does not meet the conditions for suspension. The following is a log segment (example):

[ERROR] TSCH(-1,null):2023-01-01-02:53:45.850.781 1 (dieid:0,cpuid:0) device_management_plat.c:563 suspend_ack: suspend pre check fail, hwts is busy
[EVENT] TSCH(-1,null):2023-01-01-02:53:45.850.803 2 (dieid:0,cpuid:0) device_management.c:411 process_low_power_cmd: ts suspend ack ret=1.

Possible Cause

According to the suspension process, the AI application process must exit before the system is suspended. The system can enter into suspension only when the hardware resources are idle. If the suspension conditions are not met, an error is reported. In this case, the AI application process does not exit, and hwts is detected busy when activating the suspension state. As a result, the suspension fails.

Solution

Ensure that the AI application process has ended or exited gracefully. You are advised to run the kill -2 PID command to exit the process. Replace PID with the actual process ID.