From 229b26b02ceb5f313abe341c187ed0c4a3daee1e Mon Sep 17 00:00:00 2001
From: Scott Lahteine <github@thinkyhead.com>
Date: Tue, 26 Jun 2018 18:51:39 -0500
Subject: [PATCH] Clear LED matrix without startup test

---
 Marlin/src/feature/Max7219_Debug_LEDs.cpp | 4 ++++
 Marlin/src/feature/Max7219_Debug_LEDs.h   | 3 +++
 Marlin/src/gcode/feature/leds/M7219.cpp   | 2 +-
 3 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/Marlin/src/feature/Max7219_Debug_LEDs.cpp b/Marlin/src/feature/Max7219_Debug_LEDs.cpp
index 1291aebdc..dd4f4bf47 100644
--- a/Marlin/src/feature/Max7219_Debug_LEDs.cpp
+++ b/Marlin/src/feature/Max7219_Debug_LEDs.cpp
@@ -255,6 +255,10 @@ void Max7219_Clear_Column(const uint8_t _COL_) {
   #endif
 }
 
+void Max7219_Clear() {
+  for (uint8_t r = 0; r < 8; r++) _Max7219_Set_Reg(r, 0);
+}
+
 void Max7219_Set_2_Rows(const uint8_t y, uint16_t val) {
   if (y > 6) return Max7219_Error(PSTR("Max7219_Set_2_Rows"), y, val);
   Max7219_Set_Row(y + 0, val & 0xFF); val >>= 8;
diff --git a/Marlin/src/feature/Max7219_Debug_LEDs.h b/Marlin/src/feature/Max7219_Debug_LEDs.h
index dec159cee..f00f23174 100644
--- a/Marlin/src/feature/Max7219_Debug_LEDs.h
+++ b/Marlin/src/feature/Max7219_Debug_LEDs.h
@@ -77,6 +77,9 @@ void Max7219_Clear_Column(const uint8_t col);
 void Max7219_Set_Row(const uint8_t row, const uint8_t val);
 void Max7219_Clear_Row(const uint8_t row);
 
+// Quickly clear the whole matrix
+void Max7219_Clear();
+
 // Apply custom code to update the matrix
 void Max7219_idle_tasks();
 
diff --git a/Marlin/src/gcode/feature/leds/M7219.cpp b/Marlin/src/gcode/feature/leds/M7219.cpp
index 36f9f7c7c..8aaa3ea4b 100644
--- a/Marlin/src/gcode/feature/leds/M7219.cpp
+++ b/Marlin/src/gcode/feature/leds/M7219.cpp
@@ -39,7 +39,7 @@
  */
 void GcodeSuite::M7219() {
   if (parser.seen('I'))
-    Max7219_init();
+    Max7219_Clear();
   else if (parser.seenval('R')) {
     const uint8_t r = parser.value_int();
     Max7219_Set_Row(r, parser.byteval('V'));