From f9403c8489b7de69f99c7618e0082f53ac12b513 Mon Sep 17 00:00:00 2001
From: Theo Arends <11044339+arendst@users.noreply.github.com>
Date: Sun, 3 Jan 2021 16:30:45 +0100
Subject: [PATCH] Optimize sleepdelay

Optimize sleepdelay (#10379)
---
 tasmota/tasmota.ino | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/tasmota/tasmota.ino b/tasmota/tasmota.ino
index 84c2252b1..79e648200 100644
--- a/tasmota/tasmota.ino
+++ b/tasmota/tasmota.ino
@@ -367,13 +367,19 @@ void BacklogLoop(void) {
 
 void SleepDelay(uint32_t mseconds) {
   if (mseconds) {
-    for (uint32_t wait = 0; wait < mseconds; wait++) {
-      // ESP8266 does an optimistic_yield(1000) in Serial.available()
-      // ESP32 does not so needs delay here
-#ifdef ESP32
-      delay(1);
+    uint32_t wait = millis() + mseconds;
+    while (!TimeReached(wait)) {
+#ifdef ESP8266
+      if ((wait - millis()) > 10) {  // ESP8266 does an optimistic_yield(10000) in Serial.available()
 #endif
-      if (Serial.available()) { break; }  // We need to service serial buffer ASAP as otherwise we get uart buffer overrun
+        if (Serial.available()) { return; }  // We need to service serial buffer ASAP as otherwise we get uart buffer overrun
+#ifdef ESP8266
+      } else {
+#endif
+        delay(1);
+#ifdef ESP8266
+      }
+#endif  // ESP8266
     }
   } else {
     delay(0);