Serial buffer over run work around for v2.0.0 (#9236)

* Work around for serial buffer over run

PronterFace sends a lot of M105 commands.  During long operations such
as UBL's G29 P1, G29 P2, G29 P4 and G26 this can over run the serial
buffer.   This results (very often) in a M1 (actually a M1M105) ending
up in the command queue.

Until we figure out a better way to resolve this issue, this will keep
the UBL commands from experiencing bogus commands at thier completion.

Marlin/src/HAL/HAL_AVR/MarlinSerial.cpp

     uint8_t xon_xoff_state = XON_XOFF_CHAR_SENT | XON_CHAR;
   #endif
 
+  void clear_command_queue(); 
+
   #if ENABLED(SERIAL_STATS_DROPPED_RX)
     uint8_t rx_dropped_bytes = 0;
   #endif
     // reading rx_buffer_head and updating rx_buffer_tail, the previous rx_buffer_head
     // may be written to rx_buffer_tail, making the buffer appear full rather than empty.
     CRITICAL_SECTION_START;
-      rx_buffer.head = rx_buffer.tail;
+      rx_buffer.head = rx_buffer.tail = 0;
+      clear_command_queue(); 
     CRITICAL_SECTION_END;
 
     #if ENABLED(SERIAL_XON_XOFF)

Marlin/src/config/examples/FolgerTech/i3-2020/Configuration.h

  * Override with M203
  *                                      X, Y, Z, E0 [, E1[, E2[, E3[, E4]]]]
  */
-#define DEFAULT_MAX_FEEDRATE          { 250, 250, 2, 17 }
+#define DEFAULT_MAX_FEEDRATE          { 250, 250, 4, 17 }
 
 /**
  * Default Max Acceleration (change/s) change = mm/s
  */
 #define DEFAULT_XJERK                  8.5
 #define DEFAULT_YJERK                  8.5
-#define DEFAULT_ZJERK                  0.3
+#define DEFAULT_ZJERK                  0.75
 #define DEFAULT_EJERK                  4.0
 
 //===========================================================================
   /**
    * Enable the G26 Mesh Validation Pattern tool.
    */
-  //#define G26_MESH_VALIDATION
+  #define G26_MESH_VALIDATION
   #if ENABLED(G26_MESH_VALIDATION)
     #define MESH_TEST_NOZZLE_SIZE    0.4  // (mm) Diameter of primary nozzle.
     #define MESH_TEST_LAYER_HEIGHT   0.2  // (mm) Default layer height for the G26 Mesh Validation Tool.

Marlin/src/config/examples/FolgerTech/i3-2020/Configuration_adv.h

  * Fully assembled MAX7219 boards can be found on the internet for under $2(US).
  * For example, see https://www.ebay.com/sch/i.html?_nkw=332349290049
  */
-//#define MAX7219_DEBUG
+#define MAX7219_DEBUG
 #if ENABLED(MAX7219_DEBUG)
 //#define MAX7219_CLK_PIN   64  // on RAMPS       // Configuration of the 3 pins to control the display
 //#define MAX7219_DIN_PIN   57  // on RAMPS

Marlin/src/feature/bedlevel/ubl/ubl.h

     static bool g29_parameter_parsing();
     static void find_mean_mesh_height();
     static void shift_mesh_height();
-    static void probe_entire_mesh(const float &rx, const float &ry, const bool do_ubl_mesh_map, const bool stow_probe, bool do_furthest);
+    static void probe_entire_mesh(const float &rx, const float &ry, const bool do_ubl_mesh_map, const bool stow_probe, bool do_furthest) _O0;
     static void tilt_mesh_based_on_3pts(const float &z1, const float &z2, const float &z3);
     static void tilt_mesh_based_on_probed_grid(const bool do_ubl_mesh_map);
     static void g29_what_command();
     static void save_ubl_active_state_and_disable();
     static void restore_ubl_active_state_and_leave();
     static void display_map(const int);
-    static mesh_index_pair find_closest_mesh_point_of_type(const MeshPointType, const float&, const float&, const bool, uint16_t[16]);
-    static mesh_index_pair find_furthest_invalid_mesh_point();
+    static mesh_index_pair find_closest_mesh_point_of_type(const MeshPointType, const float&, const float&, const bool, uint16_t[16]) _O0;
+    static mesh_index_pair find_furthest_invalid_mesh_point() _O0;
     static void reset();
     static void invalidate();
     static void set_all_mesh_points_to_value(const float);

Marlin/src/feature/bedlevel/ubl/ubl_G29.cpp

   #include "../../../module/planner.h"
   #include "../../../module/probe.h"
   #include "../../../gcode/gcode.h"
+  #include "../../../core/serial.h"
   #include "../../../gcode/parser.h"
   #include "../../../feature/bedlevel/bedlevel.h"
   #include "../../../libs/least_squares_fit.h"
 
   extern float meshedit_done;
   extern long babysteps_done;
-  //extern bool set_probe_deployed(bool);
-  //extern void set_bed_leveling_enabled(bool);
 
   #define SIZE_OF_LITTLE_RAISE 1
   #define BIG_RAISE_NOT_NEEDED 0
           }
         }
       }
-      safe_delay(5);
+      safe_delay(15);
       return false;
     }
 
             while (is_lcd_clicked()) idle();
             lcd_external_control = false;
             restore_ubl_active_state_and_leave();
+            lcd_quick_feedback(true);
             safe_delay(50);  // Debounce the Encoder wheel
             return;
           }
           const float measured_z = probe_pt(rawx, rawy, stow_probe, g29_verbose_level); // TODO: Needs error handling
           z_values[location.x_index][location.y_index] = measured_z;
         }
+        MYSERIAL0.flush(); // G29 P2's take a long time to complete.   PronterFace can
+                           // over run the serial character buffer with M105's without
+                           // this fix
 
       } while (location.x_index >= 0 && --max_iterations);
 
       do_blocking_move_to_z(Z_CLEARANCE_DEPLOY_PROBE);
       lcd_external_control = false;
       KEEPALIVE_STATE(IN_HANDLER);
+      lcd_quick_feedback(true);
       ubl.restore_ubl_active_state_and_leave();
     }
 
           SERIAL_PROTOCOL_F(z_values[location.x_index][location.y_index], 6);
           SERIAL_EOL();
         }
+        MYSERIAL0.flush(); // G29 P2's take a long time to complete.   PronterFace can
+                           // over run the serial character buffer with M105's without
+                           // this fix
       } while (location.x_index >= 0 && location.y_index >= 0);
 
-      if (do_ubl_mesh_map) display_map(g29_map_type);
+      if (do_ubl_mesh_map) display_map(g29_map_type);  // show user where we're probing
 
       restore_ubl_active_state_and_leave();
       KEEPALIVE_STATE(IN_HANDLER);
 
   static uint8_t ubl_state_at_invocation = 0;
 
-  #ifdef UBL_DEVEL_DEBUGGING
+  #if ENABLED(UBL_DEVEL_DEBUGGING)
     static uint8_t ubl_state_recursion_chk = 0;
   #endif
 
   void unified_bed_leveling::save_ubl_active_state_and_disable() {
-    #ifdef UBL_DEVEL_DEBUGGING
+    #if ENABLED(UBL_DEVEL_DEBUGGING)
       ubl_state_recursion_chk++;
       if (ubl_state_recursion_chk != 1) {
         SERIAL_ECHOLNPGM("save_ubl_active_state_and_disabled() called multiple times in a row.");
   }
 
   void unified_bed_leveling::restore_ubl_active_state_and_leave() {
-    #ifdef UBL_DEVEL_DEBUGGING
+    #if ENABLED(UBL_DEVEL_DEBUGGING)
       if (--ubl_state_recursion_chk) {
         SERIAL_ECHOLNPGM("restore_ubl_active_state_and_leave() called too many times.");
         #if ENABLED(NEWPANEL)
     SERIAL_ECHOLNPAIR("MESH_MAX_Y  " STRINGIFY(MESH_MAX_Y) "=", MESH_MAX_Y);
     safe_delay(50);
     SERIAL_ECHOLNPAIR("GRID_MAX_POINTS_X  ", GRID_MAX_POINTS_X);
+    safe_delay(50);
     SERIAL_ECHOLNPAIR("GRID_MAX_POINTS_Y  ", GRID_MAX_POINTS_Y);
-    safe_delay(25);
+    safe_delay(50);
     SERIAL_ECHOLNPAIR("MESH_X_DIST  ", MESH_X_DIST);
     SERIAL_ECHOLNPAIR("MESH_Y_DIST  ", MESH_Y_DIST);
-    safe_delay(25);
+    safe_delay(50);
 
     SERIAL_PROTOCOLPGM("X-Axis Mesh Points at: ");
     for (uint8_t i = 0; i < GRID_MAX_POINTS_X; i++) {
     SERIAL_EOL();
     safe_delay(50);
 
-    #ifdef UBL_DEVEL_DEBUGGING
+    #if ENABLED(UBL_DEVEL_DEBUGGING)
       SERIAL_PROTOCOLLNPAIR("ubl_state_at_invocation :", ubl_state_at_invocation);
       SERIAL_EOL();
       SERIAL_PROTOCOLLNPAIR("ubl_state_recursion_chk :", ubl_state_recursion_chk);
       lcd_return_to_status();
       do_blocking_move_to_z(Z_CLEARANCE_BETWEEN_PROBES);
       LCD_MESSAGEPGM(MSG_EDITING_STOPPED);
+      lcd_quick_feedback(true);
     }
 
     void unified_bed_leveling::fine_tune_mesh(const float &rx, const float &ry, const bool do_ubl_mesh_map) {
             do_blocking_move_to_z(h_offset + new_z); // Move the nozzle as the point is edited
           #endif
           idle();
+          MYSERIAL0.flush(); // G29 P2's take a long time to complete.   PronterFace can
+                             // over run the serial character buffer with M105's without
+                             // this fix
         } while (!is_lcd_clicked());
 
         if (!lcd_map_control) lcd_return_to_status();
         // Let's work on specifying a proper API for the LCD ASAP, OK?
         lcd_external_control = true;
 
-        // this sequence to detect an is_lcd_clicked() debounce it and leave if it is
-        // a Press and Hold is repeated in a lot of places (including G26_Mesh_Validation.cpp).   This
-        // should be redone and compressed.
         if (click_and_hold(abort_fine_tune))
           goto FINE_TUNE_EXIT;
 

Marlin/src/gcode/bedlevel/G26.cpp

             SERIAL_EOL();
           }
           idle();
+          MYSERIAL0.flush(); // G26 takes a long time to complete.   PronterFace can
+                             // over run the serial character buffer with M105's without
+                             // this fix
         }
     #if ENABLED(ULTRA_LCD)
       }
       SERIAL_EOL();
     }
     idle();
+
+    MYSERIAL0.flush(); // G26 takes a long time to complete.   PronterFace can
+                       // over run the serial character buffer with M105's without
+                       // this fix
   }
 
   #if ENABLED(ULTRA_LCD)
   set_bed_leveling_enabled(!parser.seen('D'));
 
   if (current_position[Z_AXIS] < Z_CLEARANCE_BETWEEN_PROBES) {
-SERIAL_PROTOCOLLNPGM("! move nozzle to Z_CLEARANCE_BETWEEN_PROBES height.");
-SERIAL_ECHOLNPAIR("  Z at:", current_position[Z_AXIS]);
+//  SERIAL_PROTOCOLLNPGM("! move nozzle to Z_CLEARANCE_BETWEEN_PROBES height.");
+//  SERIAL_ECHOLNPAIR("  Z at:", current_position[Z_AXIS]);
     do_blocking_move_to_z(Z_CLEARANCE_BETWEEN_PROBES);
     stepper.synchronize();
     set_current_from_destination();
-SERIAL_ECHOLNPAIR("  Z now at:", current_position[Z_AXIS]);
+//  SERIAL_ECHOLNPAIR("  Z now at:", current_position[Z_AXIS]);
   }
 
   if (turn_on_heaters() != G26_OK) goto LEAVE;
 
   // Move nozzle to the specified height for the first layer
   set_destination_from_current();
-SERIAL_PROTOCOLLNPGM("! moving nozzle to 1st layer height.");
-SERIAL_ECHOLNPAIR("  Z1 at:", current_position[Z_AXIS]);
+//SERIAL_PROTOCOLLNPGM("! moving nozzle to 1st layer height.");
+//SERIAL_ECHOLNPAIR("  Z1 at:", current_position[Z_AXIS]);
 
   destination[Z_AXIS] = g26_layer_height;
   move_to(destination, 0.0);
-  stepper.synchronize();
-  set_destination_from_current();
-SERIAL_ECHOLNPAIR("  Z2 at:", current_position[Z_AXIS]);
+//stepper.synchronize();
+//set_destination_from_current();
+//SERIAL_ECHOLNPAIR("  Z2 at:", current_position[Z_AXIS]);
   move_to(destination, g26_ooze_amount);
 
   #if ENABLED(ULTRA_LCD)
         //}
 
         print_line_from_here_to_there(rx, ry, g26_layer_height, xe, ye, g26_layer_height);
+        MYSERIAL0.flush(); // G26 takes a long time to complete.   PronterFace can
+                           // over run the serial character buffer with M105's without
+                           // this fix
 
       }
       if (look_for_lines_to_connect())
         goto LEAVE;
     }
+    MYSERIAL0.flush(); // G26 takes a long time to complete.   PronterFace can
+                       // over run the serial character buffer with M105's without
+                       // this fix
   } while (--g26_repeats && location.x_index >= 0 && location.y_index >= 0);
 
   LEAVE:

Marlin/src/gcode/queue.cpp

  * Clear the Marlin command queue
  */
 void clear_command_queue() {
-  cmd_queue_index_r = cmd_queue_index_w;
-  commands_in_queue = 0;
+  cmd_queue_index_r = cmd_queue_index_w = commands_in_queue = 0;
 }
 
 /**