From eaa6f568ee380c122129fc8142c2c928d520bc5b Mon Sep 17 00:00:00 2001
From: Scott Lahteine <sourcetree@thinkyhead.com>
Date: Sat, 4 Jun 2016 01:10:51 -0700
Subject: [PATCH] Prevent re-entrant call of Reprapworld Keypad handler

---
 Marlin/ultralcd.cpp | 39 +++++++++++++++++++++++++--------------
 Marlin/ultralcd.h   | 11 +++++++++++
 2 files changed, 36 insertions(+), 14 deletions(-)

diff --git a/Marlin/ultralcd.cpp b/Marlin/ultralcd.cpp
index baf04a14f..a68e61ebe 100755
--- a/Marlin/ultralcd.cpp
+++ b/Marlin/ultralcd.cpp
@@ -2584,22 +2584,33 @@ void lcd_update() {
 
       #if ENABLED(REPRAPWORLD_KEYPAD)
 
-        #if ENABLED(DELTA) || ENABLED(SCARA)
-          #define _KEYPAD_MOVE_ALLOWED (axis_homed[X_AXIS] && axis_homed[Y_AXIS] && axis_homed[Z_AXIS])
-        #else
-          #define _KEYPAD_MOVE_ALLOWED true
-        #endif
+        static uint8_t keypad_debounce = 0;
 
-        if (REPRAPWORLD_KEYPAD_MOVE_HOME)       reprapworld_keypad_move_home();
-        if (_KEYPAD_MOVE_ALLOWED) {
-          if (REPRAPWORLD_KEYPAD_MOVE_Z_UP)     reprapworld_keypad_move_z_up();
-          if (REPRAPWORLD_KEYPAD_MOVE_Z_DOWN)   reprapworld_keypad_move_z_down();
-          if (REPRAPWORLD_KEYPAD_MOVE_X_LEFT)   reprapworld_keypad_move_x_left();
-          if (REPRAPWORLD_KEYPAD_MOVE_X_RIGHT)  reprapworld_keypad_move_x_right();
-          if (REPRAPWORLD_KEYPAD_MOVE_Y_DOWN)   reprapworld_keypad_move_y_down();
-          if (REPRAPWORLD_KEYPAD_MOVE_Y_UP)     reprapworld_keypad_move_y_up();
+        if (!REPRAPWORLD_KEYPAD_PRESSED) {
+          if (keypad_debounce > 0) keypad_debounce--;
         }
-      #endif
+        else if (!keypad_debounce) {
+          keypad_debounce = 2;
+
+          #if DISABLED(DELTA) && Z_HOME_DIR == -1
+            if (REPRAPWORLD_KEYPAD_MOVE_Z_UP)     reprapworld_keypad_move_z_up();
+          #endif
+
+          if (axis_homed[X_AXIS] && axis_homed[Y_AXIS] && axis_homed[Z_AXIS]) {
+            #if ENABLED(DELTA) || Z_HOME_DIR != -1
+              if (REPRAPWORLD_KEYPAD_MOVE_Z_UP)   reprapworld_keypad_move_z_up();
+            #endif
+            if (REPRAPWORLD_KEYPAD_MOVE_Z_DOWN)   reprapworld_keypad_move_z_down();
+            if (REPRAPWORLD_KEYPAD_MOVE_X_LEFT)   reprapworld_keypad_move_x_left();
+            if (REPRAPWORLD_KEYPAD_MOVE_X_RIGHT)  reprapworld_keypad_move_x_right();
+            if (REPRAPWORLD_KEYPAD_MOVE_Y_DOWN)   reprapworld_keypad_move_y_down();
+            if (REPRAPWORLD_KEYPAD_MOVE_Y_UP)     reprapworld_keypad_move_y_up();
+          }
+          else {
+            if (REPRAPWORLD_KEYPAD_MOVE_HOME)     reprapworld_keypad_move_home();
+          }
+        }
+      #endif // REPRAPWORLD_KEYPAD
 
       bool encoderPastThreshold = (abs(encoderDiff) >= ENCODER_PULSES_PER_STEP);
       if (encoderPastThreshold || LCD_CLICKED) {
diff --git a/Marlin/ultralcd.h b/Marlin/ultralcd.h
index ccb6f504d..d9b6c3c0f 100644
--- a/Marlin/ultralcd.h
+++ b/Marlin/ultralcd.h
@@ -123,6 +123,17 @@
     #define REPRAPWORLD_KEYPAD_MOVE_Y_UP    (buttons_reprapworld_keypad & EN_REPRAPWORLD_KEYPAD_UP)
     #define REPRAPWORLD_KEYPAD_MOVE_X_LEFT  (buttons_reprapworld_keypad & EN_REPRAPWORLD_KEYPAD_LEFT)
 
+    #define REPRAPWORLD_KEYPAD_PRESSED      (buttons_reprapworld_keypad & ( \
+                                              EN_REPRAPWORLD_KEYPAD_F3 | \
+                                              EN_REPRAPWORLD_KEYPAD_F2 | \
+                                              EN_REPRAPWORLD_KEYPAD_F1 | \
+                                              EN_REPRAPWORLD_KEYPAD_DOWN | \
+                                              EN_REPRAPWORLD_KEYPAD_RIGHT | \
+                                              EN_REPRAPWORLD_KEYPAD_MIDDLE | \
+                                              EN_REPRAPWORLD_KEYPAD_UP | \
+                                              EN_REPRAPWORLD_KEYPAD_LEFT) \
+                                            )
+
   #endif // REPRAPWORLD_KEYPAD
 
   #if ENABLED(NEWPANEL)