Fix interrupt-based endstop detection

Marlin/endstop_interrupts.h

@@ -24,7 +24,7 @@
  * Endstop Interrupts
  *
  * Without endstop interrupts the endstop pins must be polled continually in
- * the stepper-ISR via endstops.update(), most of the time finding no change.
+ * the temperature-ISR via endstops.update(), most of the time finding no change.
  * With this feature endstops.update() is called only when we know that at
  * least one endstop has changed state, saving valuable CPU cycles.
  *
@@ -40,6 +40,9 @@
 
 #include "macros.h"
 
+// One ISR for all EXT-Interrupts
+void endstop_ISR(void) { endstops.check_possible_change(); }
+
 /**
  * Patch for pins_arduino.h (...\Arduino\hardware\arduino\avr\variants\mega\pins_arduino.h)
  *
@@ -72,8 +75,6 @@
                                     0 )
 #endif
 
-volatile uint8_t e_hit = 0; // Different from 0 when the endstops should be tested in detail.
-                            // Must be reset to 0 by the test function when finished.
 
 // Install Pin change interrupt for a pin. Can be called multiple times.
 void pciSetup(const int8_t pin) {
@@ -82,30 +83,22 @@ void pciSetup(const int8_t pin) {
   SBI(PCICR, digitalPinToPCICRbit(pin)); // enable interrupt for the group
 }
 
-// This is what is really done inside the interrupts.
-FORCE_INLINE void endstop_ISR_worker( void ) {
-  e_hit = 2; // Because the detection of a e-stop hit has a 1 step debouncer it has to be called at least twice.
-}
-
-// Use one Routine to handle each group
-// One ISR for all EXT-Interrupts
-void endstop_ISR(void) { endstop_ISR_worker(); }
 
 // Handlers for pin change interrupts
 #ifdef PCINT0_vect
-  ISR(PCINT0_vect) { endstop_ISR_worker(); }
+  ISR(PCINT0_vect) { endstop_ISR(); }
 #endif
 
 #ifdef PCINT1_vect
-  ISR(PCINT1_vect) { endstop_ISR_worker(); }
+  ISR(PCINT1_vect) { endstop_ISR(); }
 #endif
 
 #ifdef PCINT2_vect
-  ISR(PCINT2_vect) { endstop_ISR_worker(); }
+  ISR(PCINT2_vect) { endstop_ISR(); }
 #endif
 
 #ifdef PCINT3_vect
-  ISR(PCINT3_vect) { endstop_ISR_worker(); }
+  ISR(PCINT3_vect) { endstop_ISR(); }
 #endif
 
 void setup_endstop_interrupts( void ) {