From e6af980b8566c20185e24f3ed799d6e74c53ce69 Mon Sep 17 00:00:00 2001
From: Tomoatsu Shimada <shimarin@gmail.com>
Date: Wed, 11 Jul 2018 04:40:14 +0900
Subject: [PATCH] Avoid unnecessary waveform de-initialization which corrupts
 softwareserial (#4913)

---
 cores/esp8266/core_esp8266_waveform.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/cores/esp8266/core_esp8266_waveform.c b/cores/esp8266/core_esp8266_waveform.c
index 306fd3d45..1d703515d 100644
--- a/cores/esp8266/core_esp8266_waveform.c
+++ b/cores/esp8266/core_esp8266_waveform.c
@@ -205,7 +205,7 @@ int startWaveform(uint8_t pin, uint32_t timeHighUS, uint32_t timeLowUS, uint32_t
 // Stops a waveform on a pin
 int stopWaveform(uint8_t pin) {
   for (size_t i = 0; i < countof(waveform); i++) {
-    if (((pin == 16) && waveform[i].gpio16Mask) || ((pin != 16) && (waveform[i].gpioMask == 1<<pin))) {
+    if ((((pin == 16) && waveform[i].gpio16Mask) || ((pin != 16) && (waveform[i].gpioMask == 1<<pin))) && waveform[i].enabled) {
       // Note that there is no interrupt unsafety here.  The IRQ can only ever change .enabled from 1->0
       // We're also doing that, so even if an IRQ occurred it would still stay as 0.
       waveform[i].enabled = 0;