diff --git a/examples/device/cdc_dual_ports/src/tusb_config.h b/examples/device/cdc_dual_ports/src/tusb_config.h
index ea059f08a..90805397a 100644
--- a/examples/device/cdc_dual_ports/src/tusb_config.h
+++ b/examples/device/cdc_dual_ports/src/tusb_config.h
@@ -59,7 +59,7 @@
 #endif
 
 #ifndef CFG_TUSB_DEBUG
-#define CFG_TUSB_DEBUG        3
+#define CFG_TUSB_DEBUG        0
 #endif
 #ifdef CFG_TUSB_DEBUG
 #define CFG_TUSB_DEBUG_PRINTF rt_kprintf
diff --git a/examples/device/net_lwip_webserver/src/lwipopts.h b/examples/device/net_lwip_webserver/src/lwipopts.h
index c02baf47d..85028585b 100644
--- a/examples/device/net_lwip_webserver/src/lwipopts.h
+++ b/examples/device/net_lwip_webserver/src/lwipopts.h
@@ -379,7 +379,7 @@
 #define TCPIP_THREAD_STACKSIZE      RT_LWIP_TCPTHREAD_STACKSIZE
 #else
 #define TCPIP_MBOX_SIZE             8
-#define TCPIP_THREAD_PRIO           128
+#define TCPIP_THREAD_PRIO           7
 #define TCPIP_THREAD_STACKSIZE      4096
 #endif
 #define TCPIP_THREAD_NAME           "tcpip"
diff --git a/examples/device/net_lwip_webserver/src/main.c b/examples/device/net_lwip_webserver/src/main.c
index 4d44562f4..c12c0a31e 100644
--- a/examples/device/net_lwip_webserver/src/main.c
+++ b/examples/device/net_lwip_webserver/src/main.c
@@ -116,7 +116,7 @@ static err_t linkoutput_fn(struct netif *netif, struct pbuf *p) {
       tud_network_xmit(p, 0 /* unused for this example */);
       return ERR_OK;
     }
-
+    return ERR_USE;
     /* transfer execution to TinyUSB in the hopes that it will finish transmitting the prior packet */
     /*rc: if use rtos, this function still will be called? */
     // tud_task();
@@ -195,6 +195,7 @@ bool dns_query_proc(const char *name, ip4_addr_t *addr) {
 }
 
 bool tud_network_recv_cb(const uint8_t *src, uint16_t size) {
+  err_t err = ERR_OK;
   struct netif *netif = &netif_data;
 
   if (size) {
@@ -212,8 +213,8 @@ bool tud_network_recv_cb(const uint8_t *src, uint16_t size) {
     // Only call pbuf_free if not Ok else it will panic with "pbuf_free: p->ref > 0"
     // or steal it from whatever took ownership of it with undefined consequences.
     // See: https://savannah.nongnu.org/patch/index.php?10121
-    if (netif->input(p, netif) != ERR_OK) {
-      TU_LOG(2,"ERROR: netif input failed\n");
+    if (err=netif->input(p, netif),err != ERR_OK) {
+      rt_kprintf("ERROR: netif input failed, err=%d\n", err);
       pbuf_free(p);
     }
     // Signal tinyusb that the current frame has been processed.
@@ -290,9 +291,9 @@ void usb_irq_enable(){
 
 static void tusb_thread_entry(void *parameter)
 {
-    (void) parameter;
-    while (1)
-    {
+  TU_LOG(2, "TinyUSB task started\n");
+  (void) parameter;
+  while (1) {
 #if CFG_TUH_ENABLED
         tuh_task();
 #endif
@@ -349,9 +350,9 @@ int init_tinyusb(void) {
 #endif
 
 #if CFG_TUD_NCM
-  TU_LOG(2,"USB NCM network interface initialized\n");
+  rt_kprintf("USB NCM network interface initialized\n");
 #elif CFG_TUD_ECM_RNDIS
-  TU_LOG(2,"USB RNDIS/ECM network interface initialized\n");
+  rt_kprintf("USB RNDIS/ECM network interface initialized\n");
 #endif
 
   #ifdef RT_USING_HEAP
diff --git a/examples/device/net_lwip_webserver/src/tusb_config.h b/examples/device/net_lwip_webserver/src/tusb_config.h
index 0befbb365..4d5dbf5ae 100644
--- a/examples/device/net_lwip_webserver/src/tusb_config.h
+++ b/examples/device/net_lwip_webserver/src/tusb_config.h
@@ -64,6 +64,9 @@ extern "C" {
 #ifndef CFG_TUSB_DEBUG
   #define CFG_TUSB_DEBUG 3
 #endif
+#ifdef CFG_TUSB_DEBUG
+#define CFG_TUSB_DEBUG_PRINTF rt_kprintf
+#endif /* CFG_TUSB_DEBUG */
 
 // Enable Device stack
 #define CFG_TUD_ENABLED 1