samples: net: wifi: shell: tune buffer and stack sizes for frdm_imx91

Increase network buffer size and stack sizes for frdm_imx91/mimx9131
to stabilize TCP/UDP traffic (zperf) on 5GHz Wi-Fi:

- Set NET_BUF_DATA_SIZE=1600 to fix TCP RX crash caused by net_buf
  being too small to hold a TCP segment (default is 128 bytes).
  Note: NET_PKT/BUF RX/TX counts are already set to sufficient values
  in overlay_iw610.conf and do not need to be overridden here.
- Add ZPERF_WORK_Q_STACK_SIZE=8192 to fix zperf_work_q stack overflow
  during TCP TX.
- Increase NXP Wi-Fi task stack sizes (TX/CORE/SCAN/MON/POWERSAVE/
  DRIVER/WLCMGR) to prevent stack sentinel triggers.
- Increase NET_TX_STACK_SIZE and NET_RX_STACK_SIZE to 16384 to fix
  intermittent TCP TX crash (work->queue == NULL assert).
- Increase NET_MGMT_EVENT_STACK_SIZE to 16384 and SHELL_STACK_SIZE
  to 16384 for stability.

Signed-off-by: Li Long <li.long@nxp.com>

Author: LiLongNXP

samples/net/wifi/shell/boards/frdm_imx91_mimx9131.conf

@@ -21,21 +21,33 @@ CONFIG_NET_TC_THREAD_PREEMPTIVE=y
 CONFIG_NET_TCP_WORKER_PRIO=-16
 CONFIG_NET_TC_TX_THREAD_BASE_PRIO=3
 CONFIG_NET_TC_RX_THREAD_BASE_PRIO=3
+CONFIG_ZPERF_WORK_Q_STACK_SIZE=8192
 CONFIG_ZPERF_WORK_Q_THREAD_PRIORITY=3
 CONFIG_NET_SOCKETS_SERVICE_THREAD_PRIO=3
 CONFIG_NET_CONTEXT_PRIORITY=y
 CONFIG_NET_MGMT_THREAD_PRIO_CUSTOM=y
 CONFIG_NET_MGMT_THREAD_PRIORITY=3
-CONFIG_IDLE_STACK_SIZE=1024
+
+# Network buffer tuning for TCP throughput (zperf)
+CONFIG_NET_BUF_DATA_SIZE=1600
 
 # Stack sizes
-CONFIG_SHELL_STACK_SIZE=6144
+CONFIG_IDLE_STACK_SIZE=1024
+CONFIG_SHELL_STACK_SIZE=16384
+CONFIG_MAIN_STACK_SIZE=8192
 CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=4096
-CONFIG_NET_MGMT_EVENT_STACK_SIZE=4608
+CONFIG_NXP_WIFI_TX_TASK_STACK_SIZE=8192
+CONFIG_NXP_WIFI_CORE_TASK_STACK_SIZE=16384
+CONFIG_NXP_WIFI_SCAN_TASK_STACK_SIZE=8192
+CONFIG_NXP_WIFI_MON_TASK_STACK_SIZE=8192
+CONFIG_NXP_WIFI_POWERSAVE_TASK_STACK_SIZE=4096
+CONFIG_NXP_WIFI_DRIVER_TASK_STACK_SIZE=8192
+CONFIG_NXP_WIFI_WLCMGR_TASK_STACK_SIZE=8192
+CONFIG_NET_MGMT_EVENT_STACK_SIZE=16384
 CONFIG_NET_TCP_WORKQ_STACK_SIZE=2048
-CONFIG_MAIN_STACK_SIZE=8192
 CONFIG_NET_SOCKETS_SERVICE_STACK_SIZE=4096
-CONFIG_NXP_WIFI_TX_TASK_STACK_SIZE=4096
+CONFIG_NET_TX_STACK_SIZE=16384
+CONFIG_NET_RX_STACK_SIZE=16384
 
 # Speed optimization
 CONFIG_SPEED_OPTIMIZATIONS=y