Bluetooth: Controller: add Unit tests for hci_internal wrapper

This commit extracts the wrapper function in its own file, to avoid
bloating the hci_internal file, as well as tests its funcionality in a
unit test.

scripts/ci/tags.yaml

@@ -938,6 +938,11 @@ ci_tests_subsys_audio_module:
     - nrf/subsys/audio/
     - nrf/tests/subsys/audio/
 
+ci_tests_subsys_bluetooth_controller:
+  files:
+    - nrf/subsys/bluetooth/controller
+    - nrf/tests/subsys/bluetooth/controller
+
 ci_tests_subsys_mpsl:
   files:
     - nrf/subsys/mpsl/

subsys/bluetooth/controller/hci_internal.c

@@ -16,6 +16,9 @@
 #include <sdc_hci_vs.h>
 
 #include "hci_internal.h"
+#if defined(CONFIG_BT_HCI_ACL_FLOW_CONTROL)
+#include "hci_internal_wrappers.h"
+#endif
 #include "ecdh.h"
 
 #define CMD_COMPLETE_MIN_SIZE (BT_HCI_EVT_HDR_SIZE \
@@ -1947,7 +1950,7 @@ int hci_internal_msg_get(uint8_t *msg_out, sdc_hci_msg_type_t *msg_type_out)
 		return 0;
 	}
 
-	const int retval = sdc_hci_get(msg_out, msg_type_out);
+	const int retval = sdc_hci_get(msg_out, (uint8_t *)msg_type_out);
 
 #if defined(CONFIG_BT_CTLR_SDC_PAWR_SYNC)
 	if (retval == 0 && *msg_type_out == SDC_HCI_MSG_TYPE_EVT

subsys/bluetooth/controller/hci_internal_wrappers.c

@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2025 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
+ */
+
+#include "hci_internal_wrappers.h"
+#include <zephyr/sys/util.h>
+
+/* Note: When host and controller are built separately, the RX Buffer Count communicated here from
+ * the host might be exeeding the controller's TX command buffer count. This may result in the
+ * controller sending up to host_total_num_acl_data_packets, it cannot receive the acknoledgements
+ * via its TX command buffers for.
+ * As we do not propagate the TX command buffer count information to the controller, the simplest
+ * approach is to align the communicated host RX Buffer Count to it here.
+ */
+#if defined(CONFIG_BT_HCI_ACL_FLOW_CONTROL)
+int sdc_hci_cmd_cb_host_buffer_size_wrapper(const sdc_hci_cmd_cb_host_buffer_size_t *cmd_params)
+{
+	sdc_hci_cmd_cb_host_buffer_size_t ctrl_cmd_params = *cmd_params;
+	ctrl_cmd_params.host_total_num_acl_data_packets = MIN(
+		ctrl_cmd_params.host_total_num_acl_data_packets, (CONFIG_BT_BUF_CMD_TX_COUNT - 1));
+
+	return sdc_hci_cmd_cb_host_buffer_size(&ctrl_cmd_params);
+}
+#endif

subsys/bluetooth/controller/hci_internal_wrappers.h

@@ -0,0 +1,21 @@
+
+/*
+ * Copyright (c) 2020 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
+ */
+
+/** @file
+ *  @brief Internal HCI interface Wrappers
+ */
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <sdc_hci_cmd_controller_baseband.h>
+
+#ifndef HCI_INTERNAL_WRAPPERS_H__
+#define HCI_INTERNAL_WRAPPERS_H__
+
+int sdc_hci_cmd_cb_host_buffer_size_wrapper(const sdc_hci_cmd_cb_host_buffer_size_t *cmd_params);
+
+#endif

tests/subsys/bluetooth/controller/CMakeLists.txt

@@ -0,0 +1,26 @@
+#
+# Copyright (c) 2025 Nordic Semiconductor ASA
+#
+# SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
+#
+
+cmake_minimum_required(VERSION 3.20.0)
+
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(hci_cmd_cb_host_buffer_size_test)
+
+# Generate runner for the test
+test_runner_generate(src/hci_cmd_cb_host_buffer_size_test.c)
+
+# Add Unit Under Test source files
+target_sources(app PRIVATE ${ZEPHYR_NRF_MODULE_DIR}/subsys/bluetooth/controller/hci_internal_wrappers.c)
+
+# Add test source file
+target_sources(app PRIVATE src/hci_cmd_cb_host_buffer_size_test.c)
+
+# Create mocks
+cmock_handle(${ZEPHYR_NRFXLIB_MODULE_DIR}/softdevice_controller/include/sdc_hci_cmd_controller_baseband.h)
+
+# Include paths
+include_directories(${ZEPHYR_HAL_NORDIC_MODULE_DIR}/nrfx)
+include_directories(${ZEPHYR_NRF_MODULE_DIR}/subsys/bluetooth/controller)

tests/subsys/bluetooth/controller/prj.conf

@@ -0,0 +1,13 @@
+#
+# Copyright (c) 2025 Nordic Semiconductor ASA
+#
+# SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
+#
+CONFIG_BT_CENTRAL=y
+CONFIG_BT_HCI=y
+CONFIG_BT=y
+
+CONFIG_BT_HCI_ACL_FLOW_CONTROL=y
+CONFIG_BT_BUF_CMD_TX_COUNT=10
+
+CONFIG_UNITY=y

tests/subsys/bluetooth/controller/src/hci_cmd_cb_host_buffer_size_test.c

@@ -0,0 +1,60 @@
+/*
+ * Copyright (c) 2025 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
+ */
+#include <unity.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <errno.h>
+#include <zephyr/sys/util.h>
+
+#include "hci_internal_wrappers.h"
+#include "cmock_sdc_hci_cmd_controller_baseband.h"
+
+#define TEST_HOST_ACL_DATA_PCKT_LNGTH  55
+#define TEST_HOST_SYNC_DATA_PCKT_LNGTH 55
+#define TEST_HOST_NUM_SYNC_DATA_PCKTS  5555
+
+/* The unity_main is not declared in any header file. It is only defined in the generated test
+ * runner because of ncs' unity configuration. It is therefore declared here to avoid a compiler
+ * warning.
+ */
+extern int unity_main(void);
+
+typedef struct {
+	uint16_t acl_input_pckts;
+	uint16_t exp_acl_pckts;
+} test_vector_t;
+
+static const test_vector_t test_vectors[] = {
+	{5, 5},					  /* Input within range, no adjustment needed */
+	{15, (CONFIG_BT_BUF_CMD_TX_COUNT - 1)},	  /* Input exceeds TX buffer count - 1 limit */
+	{0xFF, (CONFIG_BT_BUF_CMD_TX_COUNT - 1)}, /* Maximum input value, corner case */
+};
+
+void test_sdc_hci_cmd_cb_host_buffer_size_wrapper(void)
+{
+	sdc_hci_cmd_cb_host_buffer_size_t cmd_params;
+	cmd_params.host_acl_data_packet_length = TEST_HOST_ACL_DATA_PCKT_LNGTH;
+	cmd_params.host_sync_data_packet_length = TEST_HOST_SYNC_DATA_PCKT_LNGTH;
+	cmd_params.host_total_num_sync_data_packets = TEST_HOST_NUM_SYNC_DATA_PCKTS;
+
+	for (size_t i = 0; i < ARRAY_SIZE(test_vectors); i++) {
+		const test_vector_t *v = &test_vectors[i];
+
+		sdc_hci_cmd_cb_host_buffer_size_t exp_cmd_params = cmd_params;
+		exp_cmd_params.host_total_num_acl_data_packets = v->exp_acl_pckts;
+		__cmock_sdc_hci_cmd_cb_host_buffer_size_ExpectAndReturn(&exp_cmd_params, 0);
+
+		cmd_params.host_total_num_acl_data_packets = v->acl_input_pckts;
+		sdc_hci_cmd_cb_host_buffer_size_wrapper(&cmd_params);
+	}
+}
+
+int main(void)
+{
+	(void)unity_main();
+
+	return 0;
+}

tests/subsys/bluetooth/controller/testcase.yaml

@@ -0,0 +1,8 @@
+tests:
+  bluetooth.controller:
+    platform_allow: native_sim
+    integration_platforms:
+      - native_sim
+    tags:
+      - unittest
+      - ci_tests_subsys_bluetooth_controller

tests/subsys/bluetooth/enocean/testcase.yaml

@@ -8,4 +8,4 @@ tests:
       - ci_build
     integration_platforms:
       - native_sim
-      - qemu_cortex_m3
+      - qemu_cortex_m3K

tests/subsys/mpsl/pm/testcase.yaml

@@ -1,6 +1,8 @@
 tests:
   mpsl.pm:
-    platform_allow: native_sim
+    platform_allow:
+      - native_sim
+      - native_posix
     integration_platforms:
       - native_sim
     tags: