Implemented a stepper timer reset after a long blocking cli()

or DISABLE_STEPPER_DRIVER_INTERRUPT().
If this is not done, the stepper interrupt would likely overflow,
leading to a maximum 32ms delay before the stepper interrupt wakes up.
In addition, the stepper timer overflow error would be reported
by the debug builds.

Firmware/Marlin_main.cpp

@@ -628,6 +628,8 @@ void crashdet_stop_and_save_print2()
 	cmdqueue_reset(); //empty cmdqueue
 	card.sdprinting = false;
 	card.closefile();
+  // Reset and re-enable the stepper timer just before the global interrupts are enabled.
+  st_reset_timer();
 	sei();
 }
 
@@ -1993,11 +1995,14 @@ void force_high_power_mode(bool start_high_power_section) {
 	if (silent == 1) {
 		//we are in silent mode, set to normal mode to enable crash detection
 
-
+    // Wait for the planner queue to drain and for the stepper timer routine to reach an idle state.
 		st_synchronize();
 		cli();
 		tmc2130_mode = (start_high_power_section == true) ? TMC2130_MODE_NORMAL : TMC2130_MODE_SILENT;
 		tmc2130_init();
+    // We may have missed a stepper timer interrupt due to the time spent in the tmc2130_init() routine.
+    // Be safe than sorry, reset the stepper timer before re-enabling interrupts.
+    st_reset_timer();
 		sei();
 		digipot_init();
 	}
@@ -7918,6 +7923,8 @@ void stop_and_save_print_to_ram(float z_move, float e_move)
 	card.sdprinting = false;
 //	card.closefile();
 	saved_printing = true;
+  // We may have missed a stepper timer interrupt. Be safe than sorry, reset the stepper timer before re-enabling interrupts.
+  st_reset_timer();
 	sei();
 	if ((z_move != 0) || (e_move != 0)) { // extruder or z move
 #if 1

Firmware/planner.cpp

@@ -565,8 +565,7 @@ extern volatile uint32_t step_events_completed; // The number of step events exe
 void planner_abort_hard()
 {
     // Abort the stepper routine and flush the planner queue.
-    // DISABLE_STEPPER_DRIVER_INTERRUPT
+    DISABLE_STEPPER_DRIVER_INTERRUPT();
-    TIMSK1 &= ~(1<<OCIE1A);
 
     // Now the front-end (the Marlin_main.cpp with its current_position) is out of sync.
     // First update the planner's current position in the physical motor steps.
@@ -612,7 +611,7 @@ void planner_abort_hard()
 #endif
     }
 #endif
-    // Clear the planner queue.
+    // Clear the planner queue, reset and re-enable the stepper timer.
     quickStop();
 
     // Apply inverse world correction matrix.
@@ -1297,7 +1296,12 @@ Having the real displacement of the head, we can calculate the total movement le
 #ifdef PLANNER_DIAGNOSTICS
   planner_update_queue_min_counter();
 #endif /* PLANNER_DIAGNOSTIC */
-  st_wake_up();
+
+  // The stepper timer interrupt will run continuously from now on.
+  // If there are no planner blocks to be executed by the stepper routine,
+  // the stepper interrupt ticks at 1kHz to wake up and pick a block
+  // from the planner queue if available.
+  ENABLE_STEPPER_DRIVER_INTERRUPT();
 }
 
 #ifdef ENABLE_AUTO_BED_LEVELING

Firmware/stepper.cpp

@@ -222,10 +222,6 @@ void MultiU24X24toH16(uint16_t& intRes, int32_t& longIn1, long& longIn2)
 
 // Some useful constants
 
-#define ENABLE_STEPPER_DRIVER_INTERRUPT()  TIMSK1 |= (1<<OCIE1A)
-#define DISABLE_STEPPER_DRIVER_INTERRUPT() TIMSK1 &= ~(1<<OCIE1A)
-
-
 void checkHitEndstops()
 {
  if( endstop_x_hit || endstop_y_hit || endstop_z_hit) {
@@ -308,17 +304,6 @@ bool enable_z_endstop(bool check)
 //  step_events_completed reaches block->decelerate_after after which it decelerates until the trapezoid generator is reset.
 //  The slope of acceleration is calculated with the leib ramp alghorithm.
 
-void st_wake_up() {
-  //  TCNT1 = 0;
-  ENABLE_STEPPER_DRIVER_INTERRUPT();
-}
-
-void step_wait(){
-    for(int8_t i=0; i < 6; i++){
-    }
-}
-
-
 FORCE_INLINE unsigned short calc_timer(unsigned short step_rate) {
   unsigned short timer;
   if(step_rate > MAX_STEP_FREQUENCY) step_rate = MAX_STEP_FREQUENCY;
@@ -1241,6 +1226,7 @@ void quickStop()
   DISABLE_STEPPER_DRIVER_INTERRUPT();
   while (blocks_queued()) plan_discard_current_block(); 
   current_block = NULL;
+  st_reset_timer();
   ENABLE_STEPPER_DRIVER_INTERRUPT();
 }
 

Firmware/stepper.h

@@ -23,6 +23,9 @@
 
 #include "planner.h"
 
+#define ENABLE_STEPPER_DRIVER_INTERRUPT()  TIMSK1 |= (1<<OCIE1A)
+#define DISABLE_STEPPER_DRIVER_INTERRUPT() TIMSK1 &= ~(1<<OCIE1A)
+
 #if EXTRUDERS > 2
   #define WRITE_E_STEP(v) { if(current_block->active_extruder == 2) { WRITE(E2_STEP_PIN, v); } else { if(current_block->active_extruder == 1) { WRITE(E1_STEP_PIN, v); } else { WRITE(E0_STEP_PIN, v); }}}
   #define NORM_E_DIR() { if(current_block->active_extruder == 2) { WRITE(E2_DIR_PIN, !INVERT_E2_DIR); } else { if(current_block->active_extruder == 1) { WRITE(E1_DIR_PIN, !INVERT_E1_DIR); } else { WRITE(E0_DIR_PIN, !INVERT_E0_DIR); }}}
@@ -71,11 +74,18 @@ void st_get_position_xy(long &x, long &y);
 float st_get_position_mm(uint8_t axis);
 
 
-// The stepper subsystem goes to sleep when it runs out of things to execute. Call this
+// Call this function just before re-enabling the stepper driver interrupt and the global interrupts
-// to notify the subsystem that it is time to go to work.
+// to avoid a stepper timer overflow.
-void st_wake_up();
+FORCE_INLINE void st_reset_timer()
+{
+  // Clear a possible pending interrupt on OCR1A overflow.
+  TIFR1 |= 1 << OCF1A;
+  // Reset the counter.
+  TCNT1 = 0;
+  // Wake up after 1ms from now.
+  OCR1A = 2000;
+}
 
-  
 void checkHitEndstops(); //call from somewhere to create an serial error message with the locations the endstops where hit, in case they were triggered
 bool endstops_hit_on_purpose(); //avoid creation of the message, i.e. after homing and before a routine call of checkHitEndstops();
 bool endstop_z_hit_on_purpose();

Firmware/ultralcd.cpp

@@ -3359,6 +3359,8 @@ static void lcd_silent_mode_set() {
   SilentModeMenu = !SilentModeMenu;
   eeprom_update_byte((unsigned char *)EEPROM_SILENT, SilentModeMenu);
 #ifdef TMC2130
+  // Wait until the planner queue is drained and the stepper routine achieves
+  // an idle state.
   st_synchronize();
   if (tmc2130_wait_standstill_xy(1000)) {}
 //	  MYSERIAL.print("standstill OK");
@@ -3367,6 +3369,9 @@ static void lcd_silent_mode_set() {
   cli();
 	tmc2130_mode = SilentModeMenu?TMC2130_MODE_SILENT:TMC2130_MODE_NORMAL;
 	tmc2130_init();
+  // We may have missed a stepper timer interrupt due to the time spent in tmc2130_init.
+  // Be safe than sorry, reset the stepper timer before re-enabling interrupts.
+  st_reset_timer();
   sei();
 #endif //TMC2130
   digipot_init();