diff --git a/components/lwip/core/ipv4/dhcp.c b/components/lwip/core/ipv4/dhcp.c
index d13b55710..fb7f6e081 100755
--- a/components/lwip/core/ipv4/dhcp.c
+++ b/components/lwip/core/ipv4/dhcp.c
@@ -1539,7 +1539,7 @@ again:
         break;
       case(DHCP_OPTION_DNS_SERVER):
         /* special case: there might be more than one server */
-        LWIP_ERROR("len % 4 == 0", len % 4 == 0, return ERR_VAL;);
+        //LWIP_ERROR("len % 4 == 0", len % 4 == 0, return ERR_VAL;);
         /* limit number of DNS servers */
         decode_len = LWIP_MIN(len, 4 * DNS_MAX_SERVERS);
         LWIP_ERROR("len >= decode_len", len >= decode_len, return ERR_VAL;);
@@ -1595,7 +1595,7 @@ decode_next:
         pbuf_copy_partial(q, &value, copy_len, val_offset);
         if (decode_len > 4) {
           /* decode more than one u32_t */
-          LWIP_ERROR("decode_len % 4 == 0", decode_len % 4 == 0, return ERR_VAL;);
+          //LWIP_ERROR("decode_len % 4 == 0", decode_len % 4 == 0, return ERR_VAL;);
           dhcp_got_option(dhcp, decode_idx);
           dhcp_set_option_value(dhcp, decode_idx, htonl(value));
           decode_len -= 4;
diff --git a/components/lwip/include/lwip/lwip/debug.h b/components/lwip/include/lwip/lwip/debug.h
index 973a633d9..342a55aad 100755
--- a/components/lwip/include/lwip/lwip/debug.h
+++ b/components/lwip/include/lwip/lwip/debug.h
@@ -97,6 +97,7 @@
 /** print debug message only if debug message type is enabled...
  *  AND is of correct type AND is at least LWIP_DBG_LEVEL
  */
+//#define LWIP_DEBUGF(debug, message) do { 
 #define LWIP_DEBUGF(debug, message) do { \
                                if ( \
                                    ((debug) & LWIP_DBG_ON) && \
diff --git a/components/lwip/include/lwip/port/arch/cc.h b/components/lwip/include/lwip/port/arch/cc.h
index 8e98502cc..d27cb9a2b 100644
--- a/components/lwip/include/lwip/port/arch/cc.h
+++ b/components/lwip/include/lwip/port/arch/cc.h
@@ -65,7 +65,21 @@ typedef int sys_prot_t;
 
 #include <stdio.h>
 
-#define LWIP_PLATFORM_DIAG(x)   do {printf x;} while(0)
+//#define LWIP_PLATFORM_DIAG(x)   do {printf x;} while(0)
+#if 1//def ESP32_WORKAROUND
+extern SemaphoreHandle_t stdio_mutex_tx;
+#define LWIP_PLATFORM_DIAG(message)\
+do{\
+    if (!stdio_mutex_tx) {\
+        stdio_mutex_tx = xSemaphoreCreateMutex();\
+    }\
+\
+    xSemaphoreTake(stdio_mutex_tx, portMAX_DELAY);\
+    ets_printf message;\
+    xSemaphoreGive(stdio_mutex_tx);\
+} while(0)
+#endif
+
 #define LWIP_PLATFORM_ASSERT(x) do {printf(x); sys_arch_assert(__FILE__, __LINE__);} while(0)
 
 //#define LWIP_DEBUG
diff --git a/components/lwip/include/lwip/port/lwipopts.h b/components/lwip/include/lwip/port/lwipopts.h
index 4958034d7..0658ce7f1 100755
--- a/components/lwip/include/lwip/port/lwipopts.h
+++ b/components/lwip/include/lwip/port/lwipopts.h
@@ -506,9 +506,9 @@ extern unsigned char misc_prof_get_tcp_snd_buf(void);
  * DHCP_DEBUG: Enable debugging in dhcp.c.
  */
 #define DHCP_DEBUG                      LWIP_DBG_OFF
-//#define LWIP_DEBUG                      1
-//#define TCP_DEBUG                     LWIP_DBG_ON
-#define THREAD_SAFE_DEBUG               LWIP_DBG_OFF
+#define LWIP_DEBUG                      1
+#define TCP_DEBUG                       LWIP_DBG_ON
+#define THREAD_SAFE_DEBUG               LWIP_DBG_ON
 #define LWIP_THREAD_SAFE                1
 
 #define CHECKSUM_CHECK_UDP              0
diff --git a/components/lwip/port/freertos/sys_arch.c b/components/lwip/port/freertos/sys_arch.c
index 3ae4bcda4..bdbdcc57b 100755
--- a/components/lwip/port/freertos/sys_arch.c
+++ b/components/lwip/port/freertos/sys_arch.c
@@ -292,8 +292,10 @@ sys_arch_mbox_fetch(sys_mbox_t *mbox, void **msg, u32_t timeout)
     }
   } else { // block forever for a message.
     while (1){
-
-      if (pdTRUE == xQueueReceive((*mbox)->os_mbox, &(*msg), portMAX_DELAY)){
+      LWIP_DEBUGF(THREAD_SAFE_DEBUG, ("sys_arch_mbox_fetch: fetch mbox=%p os_mbox=%p lock=%p\n", mbox, (*mbox)->os_mbox, (*mbox)->lock));
+      //if (pdTRUE == xQueueReceive((*mbox)->os_mbox, &(*msg), portMAX_DELAY)){
+      if (pdTRUE == xQueueReceive((*mbox)->os_mbox, &(*msg), 3000/portTICK_RATE_MS)){ //ESP32_WORKAROUND
+        LWIP_DEBUGF(THREAD_SAFE_DEBUG, ("sys_arch_mbox_fetch:mbox rx msg=%p\n", (*msg)));
         break;
       }
 
@@ -348,13 +350,15 @@ sys_arch_mbox_tryfetch(sys_mbox_t *mbox, void **msg)
 void
 sys_mbox_free(sys_mbox_t *mbox)
 {
-  uint8_t count = 0;
+#define MAX_POLL_CNT 100
+#define PER_POLL_DELAY 20
+  uint16_t count = 0;
   bool post_null = true;
 
   LWIP_DEBUGF(THREAD_SAFE_DEBUG, ("sys_mbox_free: set alive false\n"));
   (*mbox)->alive = false;
 
-  while ( count++ < 10 ){
+  while ( count++ < MAX_POLL_CNT ){ //ESP32_WORKAROUND
     LWIP_DEBUGF(THREAD_SAFE_DEBUG, ("sys_mbox_free:try lock=%d\n", count));
     if (!sys_mutex_trylock( &(*mbox)->lock )){
       LWIP_DEBUGF(THREAD_SAFE_DEBUG, ("sys_mbox_free:get lock ok %d\n", count));
@@ -372,14 +376,15 @@ sys_mbox_free(sys_mbox_t *mbox)
       }
     }
 
-    if (count == 10){
+    if (count == (MAX_POLL_CNT-1)){
       printf("WARNING: mbox %p had a consumer who never unblocked. Leaking!\n", (*mbox)->os_mbox);
     }
-    sys_delay_ms(20);
+    sys_delay_ms(PER_POLL_DELAY);
   }
 
   LWIP_DEBUGF(THREAD_SAFE_DEBUG, ("sys_mbox_free:free mbox\n"));
 
+#if 0 //ESP32_WORKAROUND
   if (uxQueueMessagesWaiting((*mbox)->os_mbox)) {
     xQueueReset((*mbox)->os_mbox);
     /* Line for breakpoint.  Should never break here! */
@@ -390,6 +395,7 @@ sys_mbox_free(sys_mbox_t *mbox)
   sys_mutex_free(&(*mbox)->lock);
   free(*mbox);
   *mbox = NULL;
+#endif
 }
 
 /*-----------------------------------------------------------------------------------*/