Fix for #1485

Marlin/Configuration_adv.h

@@ -228,7 +228,7 @@
 #define INVERT_Z_STEP_PIN false
 #define INVERT_E_STEP_PIN false
 
-//default stepper release if idle
+//default stepper release if idle. Set to 0 to deactivate.
 #define DEFAULT_STEPPER_DEACTIVE_TIME 60
 
 #define DEFAULT_MINIMUMFEEDRATE       0.0     // minimum feedrate