Improve Power-loss Recovery (#15135)

Marlin/src/Marlin.cpp

     bool no_stepper_sleep/*=false*/
   #endif
 ) {
+  #if ENABLED(POWER_LOSS_RECOVERY) && PIN_EXISTS(POWER_LOSS)
+    recovery.outage();
+  #endif
 
   #if ENABLED(SPI_ENDSTOPS)
     if (endstops.tmc_spi_homing.any

Marlin/src/feature/power_loss_recovery.cpp

 SdFile PrintJobRecovery::file;
 job_recovery_info_t PrintJobRecovery::info;
 const char PrintJobRecovery::filename[5] = "/PLR";
+uint8_t PrintJobRecovery::queue_index_r;
+uint32_t PrintJobRecovery::cmd_sdpos, // = 0
+         PrintJobRecovery::sdpos[BUFSIZE];
 
 #include "../sd/cardreader.h"
 #include "../lcd/ultralcd.h"
 }
 
 /**
+ * Set info fields that won't change
+ */
+void PrintJobRecovery::prepare() {
+  card.getAbsFilename(info.sd_filename);  // SD filename
+  cmd_sdpos = 0;
+}
+
+/**
  * Save the current machine state to the power-loss recovery file
  */
 void PrintJobRecovery::save(const bool force/*=false*/, const bool save_queue/*=true*/) {
   // Did Z change since the last call?
   if (force
     #if DISABLED(SAVE_EACH_CMD_MODE)      // Always save state when enabled
-      #if PIN_EXISTS(POWER_LOSS)          // Save if power loss pin is triggered
-        || READ(POWER_LOSS_PIN) == POWER_LOSS_STATE
-      #endif
       #if SAVE_INFO_INTERVAL_MS > 0       // Save if interval is elapsed
         || ELAPSED(ms, next_save_ms)
       #endif
     info.relative_mode = relative_mode;
     info.relative_modes_e = gcode.axis_relative_modes[E_AXIS];
 
-    // Commands in the queue
-    info.queue_length = save_queue ? queue.length : 0;
-    info.queue_index_r = queue.index_r;
-    COPY(info.queue_buffer, queue.command_buffer);
-
     // Elapsed print job time
     info.print_job_elapsed = print_job_timer.duration();
 
-    // SD file position
-    card.getAbsFilename(info.sd_filename);
-    info.sdpos = card.getIndex();
-
     write();
-
-    // KILL now if the power-loss pin was triggered
-    #if PIN_EXISTS(POWER_LOSS)
-      if (READ(POWER_LOSS_PIN) == POWER_LOSS_STATE) kill(PSTR(MSG_OUTAGE_RECOVERY));
-    #endif
   }
 }
 
+#if PIN_EXISTS(POWER_LOSS)
+  void PrintJobRecovery::_outage() {
+    save(true);
+    kill(PSTR(MSG_OUTAGE_RECOVERY));
+  }
+#endif
+
 /**
  * Save the recovery info the recovery file
  */
 
   #define RECOVERY_ZRAISE 2
 
+  const uint32_t resume_sdpos = info.sdpos; // Get here before the stepper ISR overwrites it
+
   #if HAS_LEVELING
     // Make sure leveling is off before any G92 and G28
     gcode.process_subcommands_now_P(PSTR("M420 S0 Z0"));
     }
   #endif
 
-  // Process commands from the old pending queue
-  uint8_t c = info.queue_length, r = info.queue_index_r;
-  for (; c--; r = (r + 1) % BUFSIZE)
-    gcode.process_subcommands_now(info.queue_buffer[r]);
-
   // Resume the SD file from the last position
   char *fn = info.sd_filename;
   sprintf_P(cmd, PSTR("M23 %s"), fn);
   gcode.process_subcommands_now(cmd);
-  sprintf_P(cmd, PSTR("M24 S%ld T%ld"), info.sdpos, info.print_job_elapsed);
+  sprintf_P(cmd, PSTR("M24 S%ld T%ld"), resume_sdpos, info.print_job_elapsed);
   gcode.process_subcommands_now(cmd);
 }
 
           DEBUG_EOL();
           DEBUG_ECHOLNPAIR("retract_hop: ", info.retract_hop);
         #endif
-        DEBUG_ECHOLNPAIR("queue_index_r: ", int(info.queue_index_r));
-        DEBUG_ECHOLNPAIR("queue_length: ", int(info.queue_length));
-        for (uint8_t i = 0; i < info.queue_length; i++) DEBUG_ECHOLNPAIR("> ", info.queue_buffer[i]);
         DEBUG_ECHOLNPAIR("sd_filename: ", info.sd_filename);
         DEBUG_ECHOLNPAIR("sdpos: ", info.sdpos);
         DEBUG_ECHOLNPAIR("print_job_elapsed: ", info.print_job_elapsed);

Marlin/src/feature/power_loss_recovery.h

   // Relative mode
   bool relative_mode, relative_modes_e;
 
-  // Command queue
-  uint8_t queue_length, queue_index_r;
-  char queue_buffer[BUFSIZE][MAX_CMD_SIZE];
-
   // SD Filename and position
   char sd_filename[MAXPATHNAMELENGTH];
-  uint32_t sdpos;
+  volatile uint32_t sdpos;
 
   // Job elapsed time
   millis_t print_job_elapsed;
     static SdFile file;
     static job_recovery_info_t info;
 
+    static uint8_t queue_index_r;     //!< Queue index of the active command
+    static uint32_t cmd_sdpos,        //!< SD position of the next command
+                    sdpos[BUFSIZE];   //!< SD positions of queued commands
+
     static void init();
+    static void prepare();
 
     static inline void setup() {
       #if PIN_EXISTS(POWER_LOSS)
       #endif
     }
 
+    // Track each command's file offsets
+    static inline uint32_t command_sdpos() { return sdpos[queue_index_r]; }
+    static inline void commit_sdpos(const uint8_t index_w) { sdpos[index_w] = cmd_sdpos; }
+
     static bool enabled;
     static void enable(const bool onoff);
     static void changed();
       , const bool save_queue=true
     );
 
+  #if PIN_EXISTS(POWER_LOSS)
+    static inline void outage() {
+      if (enabled && IS_SD_PRINTING() && READ(POWER_LOSS_PIN) == POWER_LOSS_STATE)
+        _outage();
+    }
+  #endif
+
   static inline bool valid() { return info.valid_head && info.valid_head == info.valid_foot; }
 
   #if ENABLED(DEBUG_POWER_LOSS_RECOVERY)
 
   private:
     static void write();
+
+  #if PIN_EXISTS(POWER_LOSS)
+    static void _outage();
+  #endif
 };
 
 extern PrintJobRecovery recovery;

Marlin/src/gcode/gcode.cpp

       destination[i] = current_position[i];
   }
 
-  #if ENABLED(POWER_LOSS_RECOVERY)
+  #if ENABLED(POWER_LOSS_RECOVERY) && !PIN_EXISTS(POWER_LOSS)
     // Only update power loss recovery on moves with E
     if (recovery.enabled && IS_SD_PRINTING() && seen[E_AXIS] && (seen[X_AXIS] || seen[Y_AXIS]))
       recovery.save();
 
   PORT_REDIRECT(queue.port[queue.index_r]);
 
+  #if ENABLED(POWER_LOSS_RECOVERY)
+    recovery.queue_index_r = queue.index_r;
+  #endif
+
   if (DEBUGGING(ECHO)) {
     SERIAL_ECHO_START();
     SERIAL_ECHOLN(current_command);

Marlin/src/gcode/queue.cpp

   #include "../feature/binary_protocol.h"
 #endif
 
+#if ENABLED(POWER_LOSS_RECOVERY)
+  #include "../feature/power_loss_recovery.h"
+#endif
 
 /**
  * GCode line number handling. Hosts may opt to include line numbers when
   #if NUM_SERIAL > 1
     port[index_w] = p;
   #endif
+  #if ENABLED(POWER_LOSS_RECOVERY)
+    recovery.commit_sdpos(index_w);
+  #endif
   if (++index_w >= BUFSIZE) index_w = 0;
   length++;
 }
         sd_count = 0; // clear sd line buffer
 
         _commit_command(false);
+
+        #if ENABLED(POWER_LOSS_RECOVERY)
+          recovery.cmd_sdpos = card.getIndex(); // Prime for the next _commit_command
+        #endif
       }
       else if (sd_count >= MAX_CMD_SIZE - 1) {
         /**

Marlin/src/gcode/sdcard/M24_M25.cpp

   #include "../../feature/host_actions.h"
 #endif
 
+#if ENABLED(POWER_LOSS_RECOVERY)
+  #include "../../feature/power_loss_recovery.h"
+#endif
+
 /**
  * M24: Start or Resume SD Print
  */
   if (card.isFileOpen()) {
     card.startFileprint();
     print_job_timer.start();
+    #if ENABLED(POWER_LOSS_RECOVERY)
+      recovery.prepare();
+    #endif
   }
 
   #if ENABLED(HOST_ACTION_COMMANDS)

Marlin/src/module/planner.cpp

   #include "../feature/backlash.h"
 #endif
 
+#if ENABLED(POWER_LOSS_RECOVERY)
+  #include "../feature/power_loss_recovery.h"
+#endif
+
 // Delay for delivery of first block to the stepper ISR, if the queue contains 2 or
 // fewer movements. The delay is measured in milliseconds, and must be less than 250ms
 #define BLOCK_DELAY_FOR_1ST_MOVE 100
     mixer.gradient_control(target_float[Z_AXIS]);
   #endif
 
+  #if ENABLED(POWER_LOSS_RECOVERY)
+    block->sdpos = recovery.command_sdpos();
+  #endif
+
   // Movement was accepted
   return true;
 } // _populate_block()

Marlin/src/module/planner.h

     uint32_t segment_time_us;
   #endif
 
+  #if ENABLED(POWER_LOSS_RECOVERY)
+    uint32_t sdpos;
+  #endif
+
 } block_t;
 
 #define HAS_POSITION_FLOAT ANY(LIN_ADVANCE, SCARA_FEEDRATE_SCALING, GRADIENT_MIX)

Marlin/src/module/stepper.cpp

   #include "../libs/L6470/L6470_Marlin.h"
 #endif
 
+#if ENABLED(POWER_LOSS_RECOVERY)
+  #include "../feature/power_loss_recovery.h"
+#endif
+
 // public:
 
 #if HAS_EXTRA_ENDSTOPS || ENABLED(Z_STEPPER_AUTO_ALIGN)
           return interval; // No more queued movements!
       }
 
+      #if ENABLED(POWER_LOSS_RECOVERY)
+        recovery.info.sdpos = current_block->sdpos;
+      #endif
+
       // Flag all moving axes for proper endstop handling
 
       #if IS_CORE