net: Increase net_mgmt task priority

Originally, the net_mgmt task priority is very low. Based on roaming
implementation, roaming is triggered in net_mgmt task. When running UDP
test while doing roaming, the net_mgmt task won't have much chance to
run and roaming can't be triggered.
Increase it to 3, which is same value of supplicant task.

Signed-off-by: Hui Bai <hui.bai@nxp.com>

samples/net/wifi/boards/rd_rw612_bga.conf

@@ -73,6 +73,8 @@ CONFIG_ZPERF_WORK_Q_THREAD_PRIORITY=3
 CONFIG_NET_SOCKETS_SERVICE_THREAD_PRIO=3
 CONFIG_NET_TC_SKIP_FOR_HIGH_PRIO=y
 CONFIG_NET_CONTEXT_PRIORITY=y
+CONFIG_NET_MGMT_THREAD_PRIO_CUSTOM=y
+CONFIG_NET_MGMT_THREAD_PRIORITY=3
 
 CONFIG_WIFI_NM_WPA_SUPPLICANT=y
 CONFIG_WIFI_NM_WPA_SUPPLICANT_CLI=y

subsys/net/ip/Kconfig.mgmt

@@ -126,4 +126,14 @@ config NET_DEBUG_MGMT_EVENT_STACK
 	help
 	  Add debug messages output on how much Net MGMT event stack is used.
 
+config NET_MGMT_THREAD_PRIO_CUSTOM
+	bool "Customize net mgmt thread priority"
+
+if NET_MGMT_THREAD_PRIO_CUSTOM
+config NET_MGMT_THREAD_PRIORITY
+	int "Priority of net_mgmt thread"
+	default NUM_PREEMPT_PRIORITIES
+
+endif # NET_MGMT_THREAD_PRIO_CUSTOM
+
 endif # NET_MGMT_EVENT

subsys/net/ip/net_mgmt.c

@@ -413,7 +413,9 @@ void net_mgmt_event_init(void)
 	mgmt_rebuild_global_event_mask();
 
 #if defined(CONFIG_NET_MGMT_EVENT_THREAD)
-#if defined(CONFIG_NET_TC_THREAD_COOPERATIVE)
+#if defined(CONFIG_NET_MGMT_THREAD_PRIO_CUSTOM)
+#define THREAD_PRIORITY CONFIG_NET_MGMT_THREAD_PRIORITY
+#elif defined(CONFIG_NET_TC_THREAD_COOPERATIVE)
 /* Lowest priority cooperative thread */
 #define THREAD_PRIORITY K_PRIO_COOP(CONFIG_NUM_COOP_PRIORITIES - 1)
 #else