diff --git a/example/a2dp_sink_demo.c b/example/a2dp_sink_demo.c
index 75963490b..5f8be9a1f 100644
--- a/example/a2dp_sink_demo.c
+++ b/example/a2dp_sink_demo.c
@@ -624,12 +624,9 @@ static void avrcp_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t
 static void avrcp_controller_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
     UNUSED(channel);
     UNUSED(size);
-    uint8_t  status = 0xFF;
     
     if (packet_type != HCI_EVENT_PACKET) return;
     if (hci_event_packet_get_type(packet) != HCI_EVENT_AVRCP_META) return;
-    
-    status = packet[5];
     if (!avrcp_cid) return;
 
     memset(avrcp_subevent_value, 0, sizeof(avrcp_subevent_value));
@@ -714,9 +711,7 @@ static void avrcp_controller_packet_handler(uint8_t packet_type, uint16_t channe
             printf("AVRCP Controller: Set Player App Value %s\n", avrcp_ctype2str(avrcp_subevent_player_application_value_response_get_command_type(packet)));
             break;
             
-       
         default:
-            printf("AVRCP Controller: Event 0x%02x is not parsed\n", packet[2]);
             break;
     }  
 }
diff --git a/example/a2dp_source_demo.c b/example/a2dp_source_demo.c
index 15d60cc0a..8e6140c3f 100644
--- a/example/a2dp_source_demo.c
+++ b/example/a2dp_source_demo.c
@@ -833,12 +833,9 @@ static void avrcp_target_packet_handler(uint8_t packet_type, uint16_t channel, u
 static void avrcp_controller_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
     UNUSED(channel);
     UNUSED(size);
-    uint8_t  status = 0xFF;
     
     if (packet_type != HCI_EVENT_PACKET) return;
     if (hci_event_packet_get_type(packet) != HCI_EVENT_AVRCP_META) return;
-
-    status = packet[5];
     if (!media_tracker.avrcp_cid) return;
     
     switch (packet[2]){
diff --git a/platform/posix/btstack_run_loop_posix.c b/platform/posix/btstack_run_loop_posix.c
index 1808c808f..e2723c6bd 100644
--- a/platform/posix/btstack_run_loop_posix.c
+++ b/platform/posix/btstack_run_loop_posix.c
@@ -248,7 +248,8 @@ static void btstack_run_loop_posix_set_timer(btstack_timer_source_t *a, uint32_t
 static void btstack_run_loop_posix_trigger_pipe(int fd){
     if (fd < 0) return;
     const uint8_t x = (uint8_t) 'x';
-    (void) write(fd, &x, 1);
+    ssize_t bytes_written = write(fd, &x, 1);
+    UNUSED(bytes_written);
 }
 
 // poll data sources from irq
@@ -256,7 +257,8 @@ static void btstack_run_loop_posix_trigger_pipe(int fd){
 static void btstack_run_loop_posix_poll_data_sources_handler(btstack_data_source_t * ds, btstack_data_source_callback_type_t callback_type){
     UNUSED(callback_type);
     uint8_t buffer[1];
-    (void) read(ds->source.fd, buffer, 1);
+    ssize_t bytes_read = read(ds->source.fd, buffer, 1);
+    UNUSED(bytes_read);
     // poll data sources
     btstack_run_loop_base_poll_data_sources();
 }
@@ -271,7 +273,8 @@ static void btstack_run_loop_posix_poll_data_sources_from_irq(void){
 static void btstack_run_loop_posix_process_callbacks_handler(btstack_data_source_t * ds, btstack_data_source_callback_type_t callback_type){
     UNUSED(callback_type);
     uint8_t buffer[1];
-    (void) read(ds->source.fd, buffer, 1);
+    ssize_t bytes_read = read(ds->source.fd, buffer, 1);
+    UNUSED(bytes_read);
     // execute callbacks - protect list with mutex
     while (1){
         pthread_mutex_lock(&btstack_run_loop_posix_callbacks_mutex);
diff --git a/platform/posix/btstack_signal.c b/platform/posix/btstack_signal.c
index e92af8d68..aac84fda7 100644
--- a/platform/posix/btstack_signal.c
+++ b/platform/posix/btstack_signal.c
@@ -37,6 +37,9 @@
 
 #define BTSTACK_FILE__ "btstack_signal.c"
 
+// enable System V signal API
+#define _POSIX_C_SOURCE 200809
+
 #include "btstack_signal.h"
 
 #include <pthread.h>
diff --git a/platform/posix/hci_dump_posix_fs.c b/platform/posix/hci_dump_posix_fs.c
index 876f9f2fd..952ce68d6 100644
--- a/platform/posix/hci_dump_posix_fs.c
+++ b/platform/posix/hci_dump_posix_fs.c
@@ -73,7 +73,8 @@ static char log_message_buffer[256];
 static void hci_dump_posix_fs_reset(void){
     btstack_assert(dump_file >= 0);
     (void) lseek(dump_file, 0, SEEK_SET);
-    (void) ftruncate(dump_file, 0);
+    int err = ftruncate(dump_file, 0);
+    UNUSED(err);
 }
 
 static void hci_dump_posix_fs_log_packet(uint8_t packet_type, uint8_t in, uint8_t *packet, uint16_t len) {
@@ -117,8 +118,11 @@ static void hci_dump_posix_fs_log_packet(uint8_t packet_type, uint8_t in, uint8_
             return;
     }
 
-    (void) write(dump_file, &header, header_len);
-    (void) write(dump_file, packet, len );
+    ssize_t bytes_written;
+    bytes_written = write(dump_file, &header, header_len);
+    UNUSED(bytes_written);
+    bytes_written = write(dump_file, packet, len );
+    UNUSED(bytes_written);
 }
 
 static void hci_dump_posix_fs_log_message(const char * format, va_list argptr){
@@ -152,7 +156,8 @@ int hci_dump_posix_fs_open(const char *filename, hci_dump_format_t format){
             // Datalink Type: 1001 - Un-encapsulated HCI
             0x00, 0x00, 0x03, 0xE9,
         };
-        (void) write(dump_file, &file_header, sizeof(file_header));
+        ssize_t bytes_written = write(dump_file, &file_header, sizeof(file_header));
+        UNUSED(bytes_written);
     }
     return 0;
 }
diff --git a/src/hci_cmd.h b/src/hci_cmd.h
index c385ad8f0..6c9f9b369 100644
--- a/src/hci_cmd.h
+++ b/src/hci_cmd.h
@@ -511,7 +511,6 @@ extern const hci_cmd_t hci_le_set_default_periodic_advertising_sync_transfer_par
 extern const hci_cmd_t hci_le_set_default_phy;
 extern const hci_cmd_t hci_le_set_event_mask;
 extern const hci_cmd_t hci_le_set_extended_advertising_data;
-extern const hci_cmd_t hci_le_set_extended_advertising_data;
 extern const hci_cmd_t hci_le_set_extended_advertising_enable;
 extern const hci_cmd_t hci_le_set_extended_advertising_parameters;
 extern const hci_cmd_t hci_le_set_extended_scan_enable;
diff --git a/src/mesh/mesh_proxy.c b/src/mesh/mesh_proxy.c
index dd1fff2ba..9a33dcdf8 100644
--- a/src/mesh/mesh_proxy.c
+++ b/src/mesh/mesh_proxy.c
@@ -339,7 +339,6 @@ static mesh_network_pdu_t * encrypted_proxy_configuration_ready_to_send;
 // Used to answer configuration request
 static uint16_t proxy_configuration_filter_list_len;
 static mesh_proxy_configuration_filter_type_t proxy_configuration_filter_type;
-static uint16_t primary_element_address;
 
 static void request_can_send_now_proxy_configuration_callback_handler(mesh_network_pdu_t * network_pdu){
     encrypted_proxy_configuration_ready_to_send = network_pdu;
diff --git a/src/mesh/provisioning_provisioner.c b/src/mesh/provisioning_provisioner.c
index 68db38b6e..63774f98e 100644
--- a/src/mesh/provisioning_provisioner.c
+++ b/src/mesh/provisioning_provisioner.c
@@ -91,6 +91,7 @@ static uint8_t  prov_start_authentication_method;
 static uint8_t  prov_start_authentication_action;
 static uint8_t  prov_start_authentication_size;
 static uint8_t  prov_authentication_string;
+// ConfirmationInputs = ProvisioningInvitePDUValue || ProvisioningCapabilitiesPDUValue || ProvisioningStartPDUValue || PublicKeyProvisioner || PublicKeyDevice
 static uint8_t  prov_confirmation_inputs[1 + 11 + 5 + 64 + 64];
 static uint8_t  confirmation_provisioner[16];
 static uint8_t  random_provisioner[16];
@@ -99,8 +100,6 @@ static uint8_t  remote_ec_q[64];
 static uint8_t  dhkey[32];
 static uint8_t  confirmation_salt[16];
 static uint8_t  confirmation_key[16];
-// ConfirmationInputs = ProvisioningInvitePDUValue || ProvisioningCapabilitiesPDUValue || ProvisioningStartPDUValue || PublicKeyProvisioner || PublicKeyDevice
-static uint8_t  prov_confirmation_inputs[1 + 11 + 5 + 64 + 64];
 static uint8_t provisioning_salt[16];
 static uint8_t session_key[16];
 static uint8_t session_nonce[16];