G28 O respects HOME_AFTER_DEACTIVATE

Addressing #11271

Marlin/src/gcode/calibrate/G28.cpp

@@ -192,7 +192,14 @@ void GcodeSuite::G28(const bool always_home_all) {
     }
   #endif
 
-  if (all_axes_known() && parser.boolval('O')) { // home only if needed
+  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");
@@ -201,6 +208,7 @@ void GcodeSuite::G28(const bool always_home_all) {
       #endif
       return;
     }
+  }
 
   // Wait for planner moves to finish!
   planner.synchronize();

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