NRF5340： the zephyer OS priority issue: the BLE thread and the other thread priority can be changed?

[ougengzhou]

NRF5340： the zephyer OS priority issue: the BLE thread and the other thread priority can be changed?
Does the BLE thread be the 1st priority than other thread all the time?
can the BLE thread change to lower priority? how to change it in the zephyer OS.

[Amanda Hsieh]

Hi, 

the BLE thread and the other thread priority can be changed?

Yes, a thread's priority in Zephyr RTOS can be altered up or down after the thread has been started, meaning a preemptible thread can become a cooperative thread and vice versa. See Thread Priorities. 

Does the BLE thread be the 1st priority than other thread all the time?

The BLE stack uses the System work queue (priority -1) as a cooperative thread, which gives it a high priority, but it is not unconditionally the highest priority. Any thread with a priority lower than -1 (e.g., -2, -3, etc.) would have higher priority. See the DevAcademy course: Scheduler In-Depth

can the BLE thread change to lower priority? how to change it in the zephyer OS.

What is your NCS version? Are you using standard HCI IPC (SB_CONFIG_NETCORE_IPC_RADIO_BT_HCI_IPC) or RPC  on the NetCore?

Regards,
Amanda H.