DNM: Bluetooth: Host: Reproduce no avail acl bufs in ipc driver

drivers/bluetooth/hci/ipc.c

@@ -126,14 +126,22 @@ static struct net_buf *bt_ipc_acl_recv(const uint8_t *data, size_t remaining)
 		return NULL;
 	}
 
-	buf = bt_buf_get_rx(BT_BUF_ACL_IN, K_NO_WAIT);
+	k_timeout_t rx_timeout = K_NO_WAIT;
+retry:
+	buf = bt_buf_get_rx(BT_BUF_ACL_IN, rx_timeout);
 	if (buf) {
 		memcpy((void *)&hdr, data, sizeof(hdr));
 		data += sizeof(hdr);
 		remaining -= sizeof(hdr);
 
 		net_buf_add_mem(buf, &hdr, sizeof(hdr));
 	} else {
+		if (K_TIMEOUT_EQ(rx_timeout, K_NO_WAIT)) {
+			LOG_WRN("No available ACL buffers! retrying...");
+			rx_timeout = K_FOREVER;
+			goto retry;
+		}
+
 		LOG_ERR("No available ACL buffers!");
 		return NULL;
 	}
@@ -273,6 +281,7 @@ static int bt_ipc_send(const struct device *dev, struct net_buf *buf)
 	err = ipc_service_send(&data->hci_ept, buf->data, buf->len);
 	if (err < 0) {
 		LOG_ERR("Failed to send (err %d)", err);
+		LOG_ERR("buf %p type %u len %u", buf, bt_buf_get_type(buf), buf->len);
 	}
 
 done:

tests/bsim/bluetooth/host/l2cap/stress/Kconfig.sysbuild

@@ -0,0 +1,14 @@
+# Copyright 2023 Nordic Semiconductor ASA
+# SPDX-License-Identifier: Apache-2.0
+
+source "share/sysbuild/Kconfig"
+
+config NET_CORE_BOARD
+	string
+	default "nrf5340bsim/nrf5340/cpunet" if $(BOARD_TARGET_STRING) = "NRF5340BSIM_NRF5340_CPUAPP"
+
+config NATIVE_SIMULATOR_PRIMARY_MCU_INDEX
+	int
+	# Let's pass the test arguments to the application MCU test
+	# otherwise by default they would have gone to the net core.
+	default 0 if $(BOARD_TARGET_STRING) = "NRF5340BSIM_NRF5340_CPUAPP"

tests/bsim/bluetooth/host/l2cap/stress/bt_mon.overlay

@@ -0,0 +1,18 @@
+// /dts-v1/;
+
+// /delete-node/ &uart0;
+
+/ {
+	chosen {
+		zephyr,bt-mon-uart = &uart0;
+	};
+
+/*
+	uart0: uart {
+		status = "okay";
+		compatible = "zephyr,native-tty-uart";
+		current-speed = <115200>;
+		serial-port = "/dev/ttyUSB20";
+	};
+	*/
+};

tests/bsim/bluetooth/host/l2cap/stress/compile.sh

@@ -0,0 +1,21 @@
+#!/usr/bin/env bash
+# Copyright 2025 Nordic Semiconductor ASA
+# SPDX-License-Identifier: Apache-2.0
+
+# Compile all the applications needed by the bsim tests in these subfolders
+
+#set -x #uncomment this line for debugging
+set -ue
+: "${ZEPHYR_BASE:?ZEPHYR_BASE must be set to point to the zephyr root directory}"
+
+export BOARD="nrf5340bsim/nrf5340/cpuapp"
+#export BOARD="nrf52_bsim"
+
+source ${ZEPHYR_BASE}/tests/bsim/compile.source
+
+app=tests/bsim/bluetooth/host/l2cap/stress sysbuild=1 \
+ cmake_extra_args=-DEXTRA_DTC_OVERLAY_FILE=bt_mon.overlay compile
+#app=tests/bsim/bluetooth/host/l2cap/stress conf_file=prj_nofrag.conf compile
+#app=tests/bsim/bluetooth/host/l2cap/stress conf_file=prj_syswq.conf compile
+
+wait_for_background_jobs

tests/bsim/bluetooth/host/l2cap/stress/nrf5340_cpunet-bt_ll_sw_split.conf

@@ -0,0 +1,62 @@
+CONFIG_IPC_SERVICE=y
+CONFIG_MBOX=y
+
+CONFIG_ISR_STACK_SIZE=1024
+CONFIG_IDLE_STACK_SIZE=256
+CONFIG_MAIN_STACK_SIZE=512
+CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=512
+CONFIG_IPC_SERVICE_BACKEND_RPMSG_WQ_STACK_SIZE=512
+CONFIG_HEAP_MEM_POOL_SIZE=8192
+CONFIG_CBPRINTF_REDUCED_INTEGRAL=y
+
+CONFIG_ISR_TABLES_LOCAL_DECLARATION=y
+CONFIG_LTO=y
+
+CONFIG_BT=y
+CONFIG_BT_HCI_RAW=y
+CONFIG_BT_MAX_CONN=1
+
+# Workaround: Unable to allocate command buffer when using K_NO_WAIT since
+# Host number of completed commands does not follow normal flow control.
+CONFIG_BT_BUF_CMD_TX_COUNT=60
+
+CONFIG_BT_BUF_ACL_RX_COUNT_EXTRA=60
+CONFIG_BT_BUF_EVT_RX_COUNT=61
+
+CONFIG_BT_BUF_ACL_RX_SIZE=255
+CONFIG_BT_BUF_ACL_TX_COUNT=60
+CONFIG_BT_BUF_ACL_TX_SIZE=255
+CONFIG_BT_CTLR_DATA_LENGTH_MAX=251
+
+#CONFIG_BT_BUF_ACL_RX_SIZE=81
+#CONFIG_BT_BUF_ACL_TX_COUNT=60
+#CONFIG_BT_BUF_ACL_TX_SIZE=27
+#CONFIG_BT_CTLR_DATA_LENGTH_MAX=81
+CONFIG_BT_CTLR_ADV_DATA_LEN_MAX=191
+
+CONFIG_BT_CTLR_RX_BUFFERS=10
+
+# Host features
+CONFIG_BT_EXT_ADV=y
+
+# Controller
+CONFIG_BT_LL_SW_SPLIT=y
+CONFIG_BT_CTLR_ASSERT_HANDLER=y
+#CONFIG_BT_CTLR_DTM_HCI=y
+
+# Advertising Sets and Extended Scanning
+CONFIG_BT_CTLR_ADV_EXT=y
+CONFIG_BT_CTLR_SCAN_DATA_LEN_MAX=1650
+
+# Increase the below to receive interleaved advertising chains
+CONFIG_BT_CTLR_SCAN_AUX_SET=1
+
+CONFIG_BT_CTLR_LLCP_CONN=1
+
+CONFIG_BT_CTLR_ADV_RESERVE_MAX=n
+CONFIG_BT_CTLR_CENTRAL_RESERVE_MAX=n
+CONFIG_BT_CTLR_SLOT_RESERVATION_UPDATE=n
+CONFIG_BT_CTLR_SCAN_UNRESERVED=y
+
+CONFIG_BT_CTLR_LLCP_REMOTE_PROC_CTX_BUF_NUM=1
+CONFIG_BT_CTLR_FORCE_MD_COUNT=0

tests/bsim/bluetooth/host/l2cap/stress/prj.conf

@@ -24,13 +24,13 @@ CONFIG_BT_L2CAP_TX_MTU=77
 # CONFIG_BT_BUF_ACL_TX_SIZE=81
 
 # L2CAP PDUs will be fragmented in 3 ACL packets.
-CONFIG_BT_BUF_ACL_TX_SIZE=27
+CONFIG_BT_BUF_ACL_TX_SIZE=255
 
-CONFIG_BT_BUF_ACL_TX_COUNT=4
+CONFIG_BT_BUF_ACL_TX_COUNT=60
 
 # The minimum value for this is
 # L2AP MPS + L2CAP header (4)
-CONFIG_BT_BUF_ACL_RX_SIZE=81
+CONFIG_BT_BUF_ACL_RX_SIZE=255
 
 # Governs BT_CONN_TX_MAX, and so must be >= than the max number of
 # peers, since we attempt to send one SDU per peer. The test execution
@@ -41,7 +41,7 @@ CONFIG_BT_L2CAP_TX_BUF_COUNT=6
 CONFIG_BT_CTLR_DATA_LENGTH_MAX=27
 CONFIG_BT_CTLR_RX_BUFFERS=10
 
-CONFIG_BT_MAX_CONN=10
+CONFIG_BT_MAX_CONN=1
 
 CONFIG_LOG=y
 CONFIG_ASSERT=y
@@ -53,3 +53,15 @@ CONFIG_LOG_THREAD_ID_PREFIX=y
 CONFIG_THREAD_NAME=y
 
 CONFIG_ARCH_POSIX_TRAP_ON_FATAL=y
+
+CONFIG_BT_SMP_SC_PAIR_ONLY=n
+
+CONFIG_BT_BUF_ACL_RX_COUNT_EXTRA=60
+
+CONFIG_BT_DEBUG_MONITOR_UART=y
+#CONFIG_CONSOLE=n
+CONFIG_UART_CONSOLE=n
+CONFIG_SERIAL=y
+#CONFIG_UART_NATIVE_TTY=y
+#CONFIG_UART_NATIVE_POSIX=y
+CONFIG_NRFX_UARTE0=y

tests/bsim/bluetooth/host/l2cap/stress/src/main.c

@@ -11,17 +11,48 @@
 
 #define LOG_MODULE_NAME main
 #include <zephyr/logging/log.h>
-LOG_MODULE_REGISTER(LOG_MODULE_NAME, LOG_LEVEL_INF);
+LOG_MODULE_REGISTER(LOG_MODULE_NAME, LOG_LEVEL_DBG);
 
 CREATE_FLAG(is_connected);
 CREATE_FLAG(flag_l2cap_connected);
 
-#define NUM_PERIPHERALS 6
+#define NUM_PERIPHERALS 1
 #define L2CAP_CHANS     NUM_PERIPHERALS
 #define SDU_NUM         20
 #define SDU_LEN         3000
 #define RESCHEDULE_DELAY K_MSEC(100)
 
+struct bt_conn *default_conn;
+
+static void tx_power_get(struct bt_conn *conn)
+{
+	struct bt_conn_le_tx_power power_level = {0};
+	int err;
+
+	LOG_INF("Reading TX power");
+
+	err = bt_conn_le_get_tx_power_level(conn, &power_level);
+	if (err) {
+		FAIL("Failed to get tx power level (err %d)", err);
+	}
+
+	LOG_INF("Tx power level: %d", power_level.current_level);
+}
+
+static struct k_work_q dut_work_q;
+static K_THREAD_STACK_DEFINE(dut_work_stack, 1024);
+
+static void heavy_work_handler(struct k_work *work)
+{
+	LOG_INF("Heavy work started");
+	k_busy_wait(100 * 1000);
+	LOG_INF("Heavy work done");
+
+	tx_power_get(default_conn);
+}
+
+static K_WORK_DEFINE(heavy_work, heavy_work_handler);
+
 static void sdu_destroy(struct net_buf *buf)
 {
 	LOG_DBG("%p", buf);
@@ -38,12 +69,12 @@ static void rx_destroy(struct net_buf *buf)
 
 /* Only one SDU per link will be transmitted at a time */
 NET_BUF_POOL_DEFINE(sdu_tx_pool,
-		    CONFIG_BT_MAX_CONN, BT_L2CAP_SDU_BUF_SIZE(SDU_LEN),
+		    120, BT_L2CAP_SDU_BUF_SIZE(SDU_LEN),
 		    CONFIG_BT_CONN_TX_USER_DATA_SIZE, sdu_destroy);
 
 /* Only one SDU per link will be received at a time */
 NET_BUF_POOL_DEFINE(sdu_rx_pool,
-		    CONFIG_BT_MAX_CONN, BT_L2CAP_SDU_BUF_SIZE(SDU_LEN),
+		    120, BT_L2CAP_SDU_BUF_SIZE(SDU_LEN),
 		    8, rx_destroy);
 
 static uint8_t tx_data[SDU_LEN];
@@ -251,6 +282,8 @@ static void connected(struct bt_conn *conn, uint8_t conn_err)
 {
 	char addr[BT_ADDR_LE_STR_LEN];
 
+	default_conn = conn;
+
 	bt_addr_le_to_str(bt_conn_get_dst(conn), addr, sizeof(addr));
 
 	if (conn_err) {
@@ -303,6 +336,11 @@ static void test_peripheral_main(void)
 		tx_data[i] = (uint8_t)i;
 	}
 
+	k_work_queue_start(&dut_work_q, dut_work_stack,
+			   K_THREAD_STACK_SIZEOF(dut_work_stack),
+			   K_PRIO_COOP(CONFIG_BT_RX_PRIO + 1), NULL);
+	k_thread_name_set(&dut_work_q.thread, "DUT workq");
+
 	err = bt_enable(NULL);
 	if (err) {
 		FAIL("Can't enable Bluetooth (err %d)", err);
@@ -326,6 +364,14 @@ static void test_peripheral_main(void)
 
 	LOG_DBG("Registered server PSM %x", psm);
 
+#if 0
+	k_work_submit_to_queue(&dut_work_q, &heavy_work);
+#else
+	(void)dut_work_q;
+	k_sleep(K_SECONDS(2));
+	k_work_submit(&heavy_work);
+#endif
+
 	LOG_DBG("Peripheral waiting for transfer completion");
 	while (rx_cnt < SDU_NUM) {
 		k_msleep(100);

tests/bsim/bluetooth/host/l2cap/stress/sysbuild.cmake

@@ -0,0 +1,24 @@
+# Copyright (c) 2025 Nordic Semiconductor ASA
+# SPDX-License-Identifier: Apache-2.0
+
+if(NOT("${SB_CONFIG_NET_CORE_BOARD}" STREQUAL ""))
+	set(NET_APP hci_ipc)
+	set(NET_APP_SRC_DIR ${ZEPHYR_BASE}/samples/bluetooth/${NET_APP})
+
+	ExternalZephyrProject_Add(
+		APPLICATION ${NET_APP}
+		SOURCE_DIR  ${NET_APP_SRC_DIR}
+		BOARD       ${SB_CONFIG_NET_CORE_BOARD}
+	)
+
+	set(${NET_APP}_CONF_FILE
+	 ${ZEPHYR_BASE}/tests/bsim/bluetooth/host/l2cap/stress/nrf5340_cpunet-bt_ll_sw_split.conf
+	 CACHE INTERNAL ""
+	)
+
+	native_simulator_set_primary_mcu_index(${DEFAULT_IMAGE} ${NET_APP})
+
+	native_simulator_set_child_images(${DEFAULT_IMAGE} ${NET_APP})
+endif()
+
+native_simulator_set_final_executable(${DEFAULT_IMAGE})

tests/bsim/bluetooth/host/l2cap/stress/testcase.yaml

@@ -3,20 +3,10 @@ common:
   tags:
     - bluetooth
   platform_allow:
-    - nrf52_bsim/native
+    - nrf5340bsim/nrf5340/cpuapp
   harness: bsim
 
 tests:
   bluetooth.host.l2cap.stress:
     harness_config:
       bsim_exe_name: tests_bsim_bluetooth_host_l2cap_stress_prj_conf
-  bluetooth.host.l2cap.stress_nofrag:
-    harness_config:
-      bsim_exe_name: tests_bsim_bluetooth_host_l2cap_stress_prj_nofrag_conf
-    extra_args:
-      CONF_FILE=prj_nofrag.conf
-  bluetooth.host.l2cap.stress_syswq:
-    harness_config:
-      bsim_exe_name: tests_bsim_bluetooth_host_l2cap_stress_prj_syswq_conf
-    extra_args:
-      CONF_FILE=prj_syswq.conf

tests/bsim/bluetooth/host/l2cap/stress/tests_scripts/l2cap.sh

@@ -2,6 +2,10 @@
 # Copyright (c) 2022 Nordic Semiconductor
 # SPDX-License-Identifier: Apache-2.0
 
+set -x
+
+BOARD="nrf5340bsim/nrf5340/cpuapp"
+#BOARD="nrf52_bsim"
 source ${ZEPHYR_BASE}/tests/bsim/sh_common.source
 
 # EATT test
@@ -13,15 +17,19 @@ bsim_exe=./bs_${BOARD_TS}_tests_bsim_bluetooth_host_l2cap_stress_prj_conf
 
 cd ${BSIM_OUT_PATH}/bin
 
-Execute "${bsim_exe}" -v=${verbosity_level} -s=${simulation_id} -d=0 -testid=central -rs=43
+#ATTACH_CMD=("btmon" "--tty" "%s" "--tty-speed" "115200" "&")
+ATTACH_CMD="xterm -e btmon --tty %s --tty-speed 115200 &"
+
+Execute "${bsim_exe}" -v=${verbosity_level} -s=${simulation_id} -d=0 -testid=central -rs=43 \
+    -uart0_pty_attach_cmd="${ATTACH_CMD}" -uart_pty_wait
 
-Execute "${bsim_exe}" -v=${verbosity_level} -s=${simulation_id} -d=1 -testid=peripheral -rs=42
-Execute "${bsim_exe}" -v=${verbosity_level} -s=${simulation_id} -d=2 -testid=peripheral -rs=10
-Execute "${bsim_exe}" -v=${verbosity_level} -s=${simulation_id} -d=3 -testid=peripheral -rs=23
-Execute "${bsim_exe}" -v=${verbosity_level} -s=${simulation_id} -d=4 -testid=peripheral -rs=7884
-Execute "${bsim_exe}" -v=${verbosity_level} -s=${simulation_id} -d=5 -testid=peripheral -rs=230
-Execute "${bsim_exe}" -v=${verbosity_level} -s=${simulation_id} -d=6 -testid=peripheral -rs=9
+Execute "${bsim_exe}" -v=${verbosity_level} -s=${simulation_id} -d=1 -testid=peripheral -rs=42 #--uart0_pty --uart_pty_wait
+#Execute "${bsim_exe}" -v=${verbosity_level} -s=${simulation_id} -d=2 -testid=peripheral -rs=10
+#Execute "${bsim_exe}" -v=${verbosity_level} -s=${simulation_id} -d=3 -testid=peripheral -rs=23
+#Execute "${bsim_exe}" -v=${verbosity_level} -s=${simulation_id} -d=4 -testid=peripheral -rs=7884
+#Execute "${bsim_exe}" -v=${verbosity_level} -s=${simulation_id} -d=5 -testid=peripheral -rs=230
+#Execute "${bsim_exe}" -v=${verbosity_level} -s=${simulation_id} -d=6 -testid=peripheral -rs=9
 
-Execute ./bs_2G4_phy_v1 -v=${verbosity_level} -s=${simulation_id} -D=7 -sim_length=400e6 $@
+Execute ./bs_2G4_phy_v1 -v=${verbosity_level} -s=${simulation_id} -D=2 -sim_length=400e6 $@
 
 wait_for_background_jobs