From eb2158147f4c64f34199415d1f21476da8bf1e3f Mon Sep 17 00:00:00 2001
From: dnc40085 <dnc40085@gmail.com>
Date: Fri, 3 Feb 2017 15:43:17 -0800
Subject: [PATCH] More UART glitch improvements

---
 app/pm/pmSleep.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/app/pm/pmSleep.c b/app/pm/pmSleep.c
index b5a282ca14..ad8c75b918 100644
--- a/app/pm/pmSleep.c
+++ b/app/pm/pmSleep.c
@@ -51,6 +51,11 @@ static void null_mode_check_timer_cb(void* arg){
          (READ_PERI_REG(UART_STATUS(1)) & (UART_TXFIFO_CNT<<UART_TXFIFO_CNT_S)) == 0){
         ets_timer_disarm(&null_mode_check_timer);
         suspend_all_timers();
+        //Ensure UART 0/1 TX FIFO is clear
+        SET_PERI_REG_MASK(UART_CONF0(0), UART_TXFIFO_RST);//RESET FIFO
+        CLEAR_PERI_REG_MASK(UART_CONF0(0), UART_TXFIFO_RST);
+        SET_PERI_REG_MASK(UART_CONF0(1), UART_TXFIFO_RST);//RESET FIFO
+        CLEAR_PERI_REG_MASK(UART_CONF0(1), UART_TXFIFO_RST);
         wifi_fpm_do_sleep(current_config.sleep_duration);
         return;
       }