From 427bc64ba137907fbdbc103622ae88106a31a250 Mon Sep 17 00:00:00 2001
From: Scott Lahteine <github@thinkyhead.com>
Date: Mon, 5 Nov 2018 02:19:55 -0600
Subject: [PATCH] G28 O respects HOME_AFTER_DEACTIVATE

Addressing #11271
---
 Marlin/src/gcode/calibrate/G28.cpp | 24 ++++++++++++++++--------
 Marlin/src/inc/SanityCheck.h       |  2 +-
 2 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/Marlin/src/gcode/calibrate/G28.cpp b/Marlin/src/gcode/calibrate/G28.cpp
index 6f6ea3393..8a40e2bd6 100644
--- a/Marlin/src/gcode/calibrate/G28.cpp
+++ b/Marlin/src/gcode/calibrate/G28.cpp
@@ -192,14 +192,22 @@ void GcodeSuite::G28(const bool always_home_all) {
     }
   #endif
 
-  if (all_axes_known() && parser.boolval('O')) { // home only if needed
-    #if ENABLED(DEBUG_LEVELING_FEATURE)
-      if (DEBUGGING(LEVELING)) {
-        SERIAL_ECHOLNPGM("> homing not needed, skip");
-        SERIAL_ECHOLNPGM("<<< G28");
-      }
-    #endif
-    return;
+  if (parser.boolval('O')) {
+    if (
+      #if ENABLED(HOME_AFTER_DEACTIVATE)
+        all_axes_known()  // homing needed anytime steppers deactivate
+      #else
+        all_axes_homed()  // homing needed only if never homed
+      #endif
+    ) {
+      #if ENABLED(DEBUG_LEVELING_FEATURE)
+        if (DEBUGGING(LEVELING)) {
+          SERIAL_ECHOLNPGM("> homing not needed, skip");
+          SERIAL_ECHOLNPGM("<<< G28");
+        }
+      #endif
+      return;
+    }
   }
 
   // Wait for planner moves to finish!
diff --git a/Marlin/src/inc/SanityCheck.h b/Marlin/src/inc/SanityCheck.h
index db0139be0..826351791 100644
--- a/Marlin/src/inc/SanityCheck.h
+++ b/Marlin/src/inc/SanityCheck.h
@@ -1157,7 +1157,7 @@ static_assert(X_MAX_LENGTH >= X_BED_SIZE && Y_MAX_LENGTH >= Y_BED_SIZE,
   #if ENABLED(HOME_AFTER_DEACTIVATE) || ENABLED(Z_SAFE_HOMING)
     #error "DISABLE_[XYZ] is not compatible with HOME_AFTER_DEACTIVATE or Z_SAFE_HOMING."
   #endif
-#endif // DISABLE_[XYZ]
+#endif
 
 /**
  * Filament Width Sensor