Merge branch 'bugfix/fix_tcp_master_close_sockets' into 'master'

fix for closing tcp connections and watchdog timeout

Closes IDFGH-11539 and IDFGH-11690

See merge request idf/esp-modbus!53

Author: alisitsyn

freemodbus/tcp_master/port/port_tcp_master.c

@@ -236,8 +236,6 @@ static BOOL xMBTCPPortMasterCloseConnection(MbSlaveInfo_t *pxInfo)
 static void xMBTCPPortMasterShutdown(void)
 {
     xSemaphoreGive(xShutdownSema);
-    vTaskDelete(NULL);
-    xMbPortConfig.xMbTcpTaskHandle = NULL;
 
     for (USHORT ucCnt = 0; ucCnt < MB_TCP_PORT_MAX_CONN; ucCnt++) {
         MbSlaveInfo_t* pxInfo = xMbPortConfig.pxMbSlaveInfo[ucCnt];
@@ -251,6 +249,8 @@ static void xMBTCPPortMasterShutdown(void)
         }
     }
     free(xMbPortConfig.pxMbSlaveInfo);
+    vTaskDelete(NULL);
+    xMbPortConfig.xMbTcpTaskHandle = NULL;
 }
 
 void vMBTCPPortMasterSetNetOpt(void *pvNetIf, eMBPortIpVer xIpVersion, eMBPortProto xProto)
@@ -754,6 +754,8 @@ static void vMBTCPPortMasterTask(void *pvParameters)
                     break;
                 }
                 putchar(ucDot);
+                // if we don't yield we run the risk of hogging CPU
+                vTaskDelay(pdMS_TO_TICKS(MB_TCP_CONNECTION_TIMEOUT_MS));
                 xErr = xMBTCPPortMasterConnect(pxInfo);
                 switch(xErr)
                 {