diff --git a/components/driver/test/test_spi_slave.c b/components/driver/test/test_spi_slave.c
index c0ebe7ade..b38eaa1bc 100644
--- a/components/driver/test/test_spi_slave.c
+++ b/components/driver/test/test_spi_slave.c
@@ -9,6 +9,9 @@
 #include "esp_log.h"
 #include "sdkconfig.h"
 
+#ifndef CONFIG_SPIRAM_SUPPORT
+//This test should be removed once the timing test is merged.
+
 #define PIN_NUM_MISO 25
 #define PIN_NUM_MOSI 23
 #define PIN_NUM_CLK  19
@@ -75,9 +78,6 @@ static void slave_init()
     TEST_ESP_OK( spi_slave_initialize(VSPI_HOST, &buscfg, &slvcfg, 2) );
 }
 
-#ifndef CONFIG_SPIRAM_SUPPORT
-//This test should be removed once the timing test is merged.
-
 TEST_CASE("test slave startup","[spi]")
 {
     uint8_t master_txbuf[320]=MASTER_SEND;
@@ -144,4 +144,4 @@ TEST_CASE("test slave startup","[spi]")
     ESP_LOGI(MASTER_TAG, "test passed.");
 }
 
-#endif
\ No newline at end of file
+#endif // !CONFIG_SPIRAM_SUPPORT
diff --git a/components/esp32/intr_alloc.c b/components/esp32/intr_alloc.c
index f99149702..c60973322 100644
--- a/components/esp32/intr_alloc.c
+++ b/components/esp32/intr_alloc.c
@@ -706,13 +706,18 @@ esp_err_t IRAM_ATTR esp_intr_set_in_iram(intr_handle_t handle, bool is_in_iram)
     return ESP_OK;
 }
 
+static void esp_intr_free_cb(void *arg)
+{
+    (void)esp_intr_free((intr_handle_t)arg);
+}
+
 esp_err_t esp_intr_free(intr_handle_t handle)
 {
     bool free_shared_vector=false;
     if (!handle) return ESP_ERR_INVALID_ARG;
     //Assign this routine to the core where this interrupt is allocated on.
     if (handle->vector_desc->cpu!=xPortGetCoreID()) {
-        esp_err_t ret = esp_ipc_call_blocking(handle->vector_desc->cpu, (esp_ipc_func_t)&esp_intr_free, (void *)handle);
+        esp_err_t ret = esp_ipc_call_blocking(handle->vector_desc->cpu, &esp_intr_free_cb, (void *)handle);
         return ret == ESP_OK ? ESP_OK : ESP_FAIL;
     }
     portENTER_CRITICAL(&spinlock);
diff --git a/components/mqtt/component.mk b/components/mqtt/component.mk
index 7c7715954..19e498025 100644
--- a/components/mqtt/component.mk
+++ b/components/mqtt/component.mk
@@ -2,7 +2,3 @@ COMPONENT_SUBMODULES += esp-mqtt
 COMPONENT_ADD_INCLUDEDIRS := esp-mqtt/include
 COMPONENT_SRCDIRS :=  esp-mqtt esp-mqtt/lib
 COMPONENT_PRIV_INCLUDEDIRS := esp-mqtt/lib/include
-
-ifeq ($(GCC_NOT_5_2_0), 1)
-esp-mqtt/lib/transport_ws.o: CFLAGS += -Wno-format-overflow
-endif
diff --git a/components/pthread/test/test_pthread.c b/components/pthread/test/test_pthread.c
index e2de1358f..543fbf585 100644
--- a/components/pthread/test/test_pthread.c
+++ b/components/pthread/test/test_pthread.c
@@ -22,7 +22,7 @@ TEST_CASE("pthread create join", "[pthread]")
     volatile int num = 7;
     volatile bool attr_init = false;
     void *thread_rval = NULL;
-    pthread_t new_thread = NULL;
+    pthread_t new_thread = (pthread_t)NULL;
     pthread_attr_t attr;
 
     if (TEST_PROTECT()) {
diff --git a/docs/en/get-started/index.rst b/docs/en/get-started/index.rst
index 38b06dc48..1fa8dfa3e 100644
--- a/docs/en/get-started/index.rst
+++ b/docs/en/get-started/index.rst
@@ -326,7 +326,7 @@ Some environment variables can be specified whilst calling ``make`` allowing use
 +=================+==============================================================+
 | ``ESPPORT``     | Overrides the serial port used in ``flash`` and ``monitor``. |
 |                 |                                                              |
-|                 | Examples: ``make flash ESPPORT=/dev/tty/USB0``,              |
+|                 | Examples: ``make flash ESPPORT=/dev/ttyUSB1``,               |
 |                 | ``make monitor ESPPORT=COM1``                                |
 +-----------------+--------------------------------------------------------------+
 | ``ESPBAUD``     | Overrides the serial baud rate when flashing the ESP32.      |
@@ -339,7 +339,7 @@ Some environment variables can be specified whilst calling ``make`` allowing use
 +-----------------+--------------------------------------------------------------+
 
 .. note::
-    Users can export environment variables (e.g. ``export ESPPORT=/dev/tty/USB0``).
+    Users can export environment variables (e.g. ``export ESPPORT=/dev/ttyUSB1``).
     All subsequent calls of ``make`` within the same terminal session will use 
     the exported value given that the variable is not simultaneously overridden.