Enable button debouncing also in modal mode (!lcd_update_enabled). In lcd_clicked() consume click event immediately.

Firmware/lcd.cpp

@@ -686,7 +686,11 @@ LongTimer lcd_timeoutToStatus;
 uint8_t lcd_clicked(void)
 {
 	bool clicked = LCD_CLICKED;
-	if(clicked) lcd_button_pressed = 0;
+	if(clicked)
+	{
+	    lcd_button_pressed = 0;
+	    lcd_buttons &= 0xff^EN_C;
+	}
     return clicked;
 }
 
@@ -709,7 +713,7 @@ Sound_MakeSound(e_SOUND_TYPE_ButtonEcho);
 void lcd_quick_feedback(void)
 {
   lcd_draw_update = 2;
-  lcd_button_pressed = false;  
+  lcd_button_pressed = false;
   lcd_beeper_quick_feedback();
 }
 
@@ -766,51 +770,42 @@ void lcd_buttons_update(void)
 	uint8_t newbutton = 0;
 	if (READ(BTN_EN1) == 0)  newbutton |= EN_A;
 	if (READ(BTN_EN2) == 0)  newbutton |= EN_B;
-	if (lcd_update_enabled)
-	{ //if we are in non-modal mode, long press can be used and short press triggers with button release
-		if (READ(BTN_ENC) == 0)
-		{ //button is pressed	  
-			lcd_timeoutToStatus.start();
-			if (!buttonBlanking.running() || buttonBlanking.expired(BUTTON_BLANKING_TIME)) {
-				buttonBlanking.start();
-		        safetyTimer.start();
-				if ((lcd_button_pressed == 0) && (lcd_long_press_active == 0))
-				{
-					longPressTimer.start();
-					lcd_button_pressed = 1;
-				}
-				else
-				{
-					if (longPressTimer.expired(LONG_PRESS_TIME))
-					{
-						lcd_long_press_active = 1;
-						if (lcd_longpress_func)
-							lcd_longpress_func();
-					}
-				}
-			}
-		}
-		else
-		{ //button not pressed
-			if (lcd_button_pressed)
-			{ //button was released
-				buttonBlanking.start();
-				if (lcd_long_press_active == 0)
-				{ //button released before long press gets activated
-					newbutton |= EN_C;
-				}
-				//else if (menu_menu == lcd_move_z) lcd_quick_feedback(); 
-				//lcd_button_pressed is set back to false via lcd_quick_feedback function
-			}
-			else
-				lcd_long_press_active = 0;
-		}
-	}
-	else
-	{ //we are in modal mode
-		if (READ(BTN_ENC) == 0)
-			newbutton |= EN_C; 
-	}
+
+    if (READ(BTN_ENC) == 0)
+    { //button is pressed
+        lcd_timeoutToStatus.start();
+        if (!buttonBlanking.running() || buttonBlanking.expired(BUTTON_BLANKING_TIME)) {
+            buttonBlanking.start();
+            safetyTimer.start();
+            if ((lcd_button_pressed == 0) && (lcd_long_press_active == 0))
+            {
+                //long press is not possible in modal mode
+                if (lcd_update_enabled) longPressTimer.start();
+                lcd_button_pressed = 1;
+            }
+            else if (longPressTimer.expired(LONG_PRESS_TIME))
+            {
+                lcd_long_press_active = 1;
+                if (lcd_longpress_func)
+                    lcd_longpress_func();
+            }
+        }
+    }
+    else
+    { //button not pressed
+        if (lcd_button_pressed)
+        { //button was released
+            buttonBlanking.start();
+            if (lcd_long_press_active == 0)
+            { //button released before long press gets activated
+                newbutton |= EN_C;
+            }
+            //else if (menu_menu == lcd_move_z) lcd_quick_feedback();
+            //lcd_button_pressed is set back to false via lcd_quick_feedback function
+        }
+        else
+            lcd_long_press_active = 0;
+    }
 
 	lcd_buttons = newbutton;
 	//manage encoder rotation

Firmware/menu.cpp

@@ -236,6 +236,8 @@ uint8_t menu_item_function_P(const char* str, menu_func_t func)
 		if (menu_clicked && (lcd_encoder == menu_item))
 		{
 			menu_clicked = false;
+            lcd_button_pressed = 0;
+            lcd_buttons &= 0xff^EN_C;
 			lcd_update_enabled = 0;
 			if (func) func();
 			lcd_update_enabled = 1;

Firmware/ultralcd.cpp

@@ -463,6 +463,8 @@ static uint8_t menu_item_sdfile(const char*
 		}
 		if (menu_clicked && (lcd_encoder == menu_item))
 		{
+		    lcd_button_pressed = 0;
+		    lcd_buttons &= 0xff^EN_C;
 			menu_action_sdfile(str_fn);
 			return menu_item_ret();
 		}