From 9bf1bd93c049dbe511ba74d7c2c749ecd64c85cd Mon Sep 17 00:00:00 2001
From: Theo Arends <11044339+arendst@users.noreply.github.com>
Date: Sun, 5 Feb 2023 12:52:21 +0100
Subject: [PATCH] Add some display safeguards fixing power issues at restart

---
 .../tasmota_xdrv_driver/xdrv_13_display.ino   | 22 ++++++++++++-------
 .../xdsp_17_universal.ino                     |  2 +-
 2 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/tasmota/tasmota_xdrv_driver/xdrv_13_display.ino b/tasmota/tasmota_xdrv_driver/xdrv_13_display.ino
index 05bc7db16..5c4ce996e 100644
--- a/tasmota/tasmota_xdrv_driver/xdrv_13_display.ino
+++ b/tasmota/tasmota_xdrv_driver/xdrv_13_display.ino
@@ -237,7 +237,7 @@ uint16_t dsp_rad;
 uint16_t dsp_color;
 int16_t dsp_len;
 
-uint8_t disp_power = 0;
+int8_t disp_power = -1;
 uint8_t disp_device = 0;
 uint8_t disp_refresh = 1;
 uint8_t disp_autodraw = 1;
@@ -293,9 +293,10 @@ void DisplayDrawStringAt(uint16_t x, uint16_t y, char *str, uint16_t color, uint
   XdspCall(FUNC_DISPLAY_DRAW_STRING);
 }
 
-void DisplayOnOff(uint8_t on)
-{
-  ExecuteCommandPower(disp_device, on, SRC_DISPLAY);
+void DisplayOnOff(uint8_t on) {
+  if (disp_device) {
+    ExecuteCommandPower(disp_device, on, SRC_DISPLAY);
+  }
 }
 
 /*-------------------------------------------------------------------------------------------*/
@@ -1838,8 +1839,10 @@ void DisplayLocalSensor(void)
  * Public
 \*********************************************************************************************/
 
-void DisplayInitDriver(void)
-{
+void DisplayInitDriver(void) {
+
+
+
   XdspCall(FUNC_DISPLAY_INIT_DRIVER);
 
 //  AddLog(LOG_LEVEL_DEBUG, PSTR(D_LOG_DEBUG "Display model %d"), Settings->display_model);
@@ -1890,8 +1893,9 @@ void DisplayInitDriver(void)
   }
 }
 
-void DisplaySetPower(void)
-{
+void DisplaySetPower(void) {
+  if (!disp_device) { return; }  // Not initialized yet
+
   disp_power = bitRead(XdrvMailbox.index, disp_device -1);
 
 //AddLog(LOG_LEVEL_DEBUG, PSTR("DSP: Power %d"), disp_power);
@@ -1995,6 +1999,8 @@ void CmndDisplayMode(void) {
 
 // Apply the current display dimmer
 void ApplyDisplayDimmer(void) {
+  if ((disp_power < 0) || !disp_device) { return; }  // Not initialized yet
+
   uint8_t dimmer8 = changeUIntScale(GetDisplayDimmer(), 0, 100, 0, 255);
   uint16_t dimmer10_gamma = ledGamma10(dimmer8);
   if (dimmer8 && !(disp_power)) {
diff --git a/tasmota/tasmota_xdsp_display/xdsp_17_universal.ino b/tasmota/tasmota_xdsp_display/xdsp_17_universal.ino
index 68dd09af1..c3154cd60 100644
--- a/tasmota/tasmota_xdsp_display/xdsp_17_universal.ino
+++ b/tasmota/tasmota_xdsp_display/xdsp_17_universal.ino
@@ -436,7 +436,7 @@ int8_t cs;
     Settings->display_width = renderer->width();
     Settings->display_height = renderer->height();
 
-//    ApplyDisplayDimmer();  // Not allowed here. Way too early in initi sequence. IE power state has not even been set at this point in time
+    ApplyDisplayDimmer();
 
 #ifdef SHOW_SPLASH
     if (!Settings->flag5.display_no_splash) {