diff --git a/components/esp32/include/rom/uart.h b/components/esp32/include/rom/uart.h
index aa3cf59217..81fa26c238 100644
--- a/components/esp32/include/rom/uart.h
+++ b/components/esp32/include/rom/uart.h
@@ -18,6 +18,8 @@
 #include "esp_types.h"
 #include "esp_attr.h"
 #include "ets_sys.h"
+#include "soc/soc.h"
+#include "soc/uart_reg.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -260,11 +262,16 @@ void uart_tx_flush(uint8_t uart_no);
 /**
   * @brief Wait until uart tx full empty and the last char send ok.
   *
-  * @param  uint8_t uart_no : 0 for UART0, 1 for UART1.
+  * @param  uart_no : 0 for UART0, 1 for UART1, 2 for UART2
   *
-  * @return None.
+  * The function defined in ROM code has a bug, so we define the correct version
+  * here for compatibility.
   */
-void uart_tx_wait_idle(uint8_t uart_no);
+static inline void uart_tx_wait_idle(uint8_t uart_no) {
+    while(REG_GET_FIELD(UART_STATUS_REG(uart_no), UART_ST_UTX_OUT)) {
+        ;
+    }
+}
 
 /**
   * @brief Get an input char from message channel.
diff --git a/components/esp32/lib_printf.c b/components/esp32/lib_printf.c
index a2aff4cf56..417e71bdf7 100644
--- a/components/esp32/lib_printf.c
+++ b/components/esp32/lib_printf.c
@@ -62,11 +62,8 @@ int phy_printf(const char* format, ...)
 
 int rtc_printf(const char* format, ...)
 {
-    va_list arg;
-    va_start(arg, format);
-    int res = lib_printf("rtc", format, arg);
-    va_end(arg);
-    return res;
+    // librtc.a printf temporary disabled due to UART baud rate switching bug.
+    return 0;
 }
 
 int wpa_printf(const char* format, ...)
diff --git a/components/esp32/system_api.c b/components/esp32/system_api.c
index 36a5f806da..e8013441b1 100644
--- a/components/esp32/system_api.c
+++ b/components/esp32/system_api.c
@@ -105,10 +105,10 @@ void IRAM_ATTR esp_restart(void)
     Cache_Read_Disable(0);
     Cache_Read_Disable(1);
 
-    // Flush any data left in UART FIFO
-    uart_tx_flush(0);
-    uart_tx_flush(1);
-    uart_tx_flush(2);
+    // Flush any data left in UART FIFOs
+    uart_tx_wait_idle(0);
+    uart_tx_wait_idle(1);
+    uart_tx_wait_idle(2);
 
     // Reset wifi/bluetooth (bb/mac)
     SET_PERI_REG_MASK(DPORT_WIFI_RST_EN_REG, 0x1f);