From 7249e2103b11640e1985fc34990d79a3421c7858 Mon Sep 17 00:00:00 2001
From: Scott Lahteine <thinkyhead@users.noreply.github.com>
Date: Sun, 5 Sep 2021 16:53:04 -0500
Subject: [PATCH] Save labor on doc rewriting

---
 .../dogm/ultralcd_st7920_u8glib_rrd_AVR.cpp   | 24 ++++++++++++++-----
 1 file changed, 18 insertions(+), 6 deletions(-)

diff --git a/Marlin/src/lcd/dogm/ultralcd_st7920_u8glib_rrd_AVR.cpp b/Marlin/src/lcd/dogm/ultralcd_st7920_u8glib_rrd_AVR.cpp
index 7b6e73a3ba5b..7e3b9ea761cf 100644
--- a/Marlin/src/lcd/dogm/ultralcd_st7920_u8glib_rrd_AVR.cpp
+++ b/Marlin/src/lcd/dogm/ultralcd_st7920_u8glib_rrd_AVR.cpp
@@ -46,7 +46,11 @@
   #ifndef CPU_ST7920_DELAY_1
     #define BOARD_ST7920_DELAY_1 0
   #endif
-  #define ST7920_DELAY_1 _MAX(BOARD_ST7920_DELAY_1, CPU_ST7920_DELAY_1, LCD_ST7920_DELAY_1)
+  #if BOARD_ST7920_DELAY_1 || CPU_ST7920_DELAY_1 || LCD_ST7920_DELAY_1
+    #define ST7920_DELAY_1 DELAY_NS(_MAX(BOARD_ST7920_DELAY_1, CPU_ST7920_DELAY_1, LCD_ST7920_DELAY_1))
+  #else
+    #define ST7920_DELAY_1
+  #endif
 #endif
 #ifndef ST7920_DELAY_2
   #ifndef LCD_ST7920_DELAY_2
@@ -58,7 +62,11 @@
   #ifndef CPU_ST7920_DELAY_2
     #define BOARD_ST7920_DELAY_2 0
   #endif
-  #define ST7920_DELAY_2 _MAX(BOARD_ST7920_DELAY_2, CPU_ST7920_DELAY_2, LCD_ST7920_DELAY_2)
+  #if BOARD_ST7920_DELAY_2 || CPU_ST7920_DELAY_2 || LCD_ST7920_DELAY_2
+    #define ST7920_DELAY_2 DELAY_NS(_MAX(BOARD_ST7920_DELAY_2, CPU_ST7920_DELAY_2, LCD_ST7920_DELAY_2))
+  #else
+    #define ST7920_DELAY_2
+  #endif
 #endif
 #ifndef ST7920_DELAY_3
   #ifndef LCD_ST7920_DELAY_3
@@ -70,7 +78,11 @@
   #ifndef CPU_ST7920_DELAY_3
     #define BOARD_ST7920_DELAY_3 0
   #endif
-  #define ST7920_DELAY_3 _MAX(BOARD_ST7920_DELAY_3, CPU_ST7920_DELAY_3, LCD_ST7920_DELAY_3)
+  #if BOARD_ST7920_DELAY_3 || CPU_ST7920_DELAY_3 || LCD_ST7920_DELAY_3
+    #define ST7920_DELAY_3 DELAY_NS(_MAX(BOARD_ST7920_DELAY_3, CPU_ST7920_DELAY_3, LCD_ST7920_DELAY_3))
+  #else
+    #define ST7920_DELAY_3
+  #endif
 #endif
 
 #ifdef ARDUINO_ARCH_STM32F1
@@ -80,9 +92,9 @@
 #endif
 
 #define ST7920_SND_BIT do{ \
-  WRITE(ST7920_CLK_PIN, LOW);             DELAY_NS(ST7920_DELAY_1); \
-  WRITE(ST7920_DAT_PIN, ST7920_DAT(val)); DELAY_NS(ST7920_DELAY_2); \
-  WRITE(ST7920_CLK_PIN, HIGH);            DELAY_NS(ST7920_DELAY_3); \
+  WRITE(ST7920_CLK_PIN, LOW);             ST7920_DELAY_1; \
+  WRITE(ST7920_DAT_PIN, ST7920_DAT(val)); ST7920_DELAY_2; \
+  WRITE(ST7920_CLK_PIN, HIGH);            ST7920_DELAY_3; \
   val <<= 1; }while(0)
 
 // Optimize this code with -O3