From 56c32f5360b166d51ee8f0c38efa2381a684e6a4 Mon Sep 17 00:00:00 2001
From: GMagician <3684609+GMagician@users.noreply.github.com>
Date: Thu, 29 Sep 2022 22:45:10 +0200
Subject: [PATCH 1/6] Lin Advance K per extruder

---
 Marlin/Configuration_adv.h     | 14 +++++++-------
 Marlin/src/inc/SanityCheck.h   | 12 ++++++++++--
 Marlin/src/module/settings.cpp |  5 +++--
 3 files changed, 20 insertions(+), 11 deletions(-)

diff --git a/Marlin/Configuration_adv.h b/Marlin/Configuration_adv.h
index cb327e9b730d..79c6f0beadab 100644
--- a/Marlin/Configuration_adv.h
+++ b/Marlin/Configuration_adv.h
@@ -1,4 +1,4 @@
-/**
+/**
  * Marlin 3D Printer Firmware
  * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
  *
@@ -2064,12 +2064,12 @@
  */
 //#define LIN_ADVANCE
 #if ENABLED(LIN_ADVANCE)
-  //#define EXTRA_LIN_ADVANCE_K // Add a second linear advance constant, configurable with M900.
-  #define LIN_ADVANCE_K 0.22    // Unit: mm compression per 1mm/s extruder speed
-  //#define LA_DEBUG            // Print debug information to serial during operation. Disable for production use.
-  //#define EXPERIMENTAL_SCURVE // Allow S-Curve Acceleration to be used with LA.
-  //#define ALLOW_LOW_EJERK     // Allow a DEFAULT_EJERK value of <10. Recommended for direct drive hotends.
-  //#define EXPERIMENTAL_I2S_LA // Allow I2S_STEPPER_STREAM to be used with LA. Performance degrades as the LA step rate reaches ~20kHz.
+  //#define EXTRA_LIN_ADVANCE_K   // Add a second linear advance constant, configurable with M900.
+  #define LIN_ADVANCE_K { 0.22 }  // Unit: mm compression per 1mm/s extruder speed
+  //#define LA_DEBUG              // Print debug information to serial during operation. Disable for production use.
+  //#define EXPERIMENTAL_SCURVE   // Allow S-Curve Acceleration to be used with LA.
+  //#define ALLOW_LOW_EJERK       // Allow a DEFAULT_EJERK value of <10. Recommended for direct drive hotends.
+  //#define EXPERIMENTAL_I2S_LA   // Allow I2S_STEPPER_STREAM to be used with LA. Performance degrades as the LA step rate reaches ~20kHz.
 #endif
 
 // @section leveling
diff --git a/Marlin/src/inc/SanityCheck.h b/Marlin/src/inc/SanityCheck.h
index e9675feaf1d4..c237b823e68c 100644
--- a/Marlin/src/inc/SanityCheck.h
+++ b/Marlin/src/inc/SanityCheck.h
@@ -1328,10 +1328,18 @@ static_assert(Y_MAX_LENGTH >= Y_BED_SIZE, "Movement bounds (Y_MIN_POS, Y_MAX_POS
  * Linear Advance 1.5 - Check K value range
  */
 #if ENABLED(LIN_ADVANCE)
+  constexpr float lak[] = LIN_ADVANCE_K;
+  static_assert(COUNT(lak) == EXTRUDERS, "LIN_ADVANCE_K must be an array EXTRUDERS long.");
   static_assert(
-    WITHIN(LIN_ADVANCE_K, 0, 10),
-    "LIN_ADVANCE_K must be a value from 0 to 10 (Changed in LIN_ADVANCE v1.5, Marlin 1.1.9)."
+    WITHIN(lak[0], 0, 10),
+    "LIN_ADVANCE_K must be values from 0 to 10 (Changed in LIN_ADVANCE v1.5, Marlin 1.1.9)."
   );
+  #if EXTRUDERS > 1
+    static_assert(
+      WITHIN(lak[1], 0, 10),
+      "LIN_ADVANCE_K must be values from 0 to 10 (Changed in LIN_ADVANCE v1.5, Marlin 1.1.9)."
+    );
+  #endif
   #if ENABLED(S_CURVE_ACCELERATION) && DISABLED(EXPERIMENTAL_SCURVE)
     #error "LIN_ADVANCE and S_CURVE_ACCELERATION may not play well together! Enable EXPERIMENTAL_SCURVE to continue."
   #elif ENABLED(DIRECT_STEPPING)
diff --git a/Marlin/src/module/settings.cpp b/Marlin/src/module/settings.cpp
index 2b6a98b0452f..6aa08ba2daed 100644
--- a/Marlin/src/module/settings.cpp
+++ b/Marlin/src/module/settings.cpp
@@ -3208,9 +3208,10 @@ void MarlinSettings::reset() {
   //
 
   #if ENABLED(LIN_ADVANCE)
+    constexpr float linAdvanceK[] = LIN_ADVANCE_K;
     EXTRUDER_LOOP() {
-      planner.extruder_advance_K[e] = LIN_ADVANCE_K;
-      TERN_(EXTRA_LIN_ADVANCE_K, other_extruder_advance_K[e] = LIN_ADVANCE_K);
+      planner.extruder_advance_K[e] = linAdvanceK[e];
+      TERN_(EXTRA_LIN_ADVANCE_K, other_extruder_advance_K[e] = linAdvanceK[e]);
     }
   #endif
 

From 1b0e0c44ae39049191e57c44c47967e09dae01ac Mon Sep 17 00:00:00 2001
From: Scott Lahteine <thinkyhead@users.noreply.github.com>
Date: Sat, 1 Oct 2022 17:06:16 -0500
Subject: [PATCH 2/6] apply DISTINCT_E_FACTORS

---
 Marlin/Configuration_adv.h                | 10 +++++++---
 Marlin/src/gcode/feature/advance/M900.cpp | 22 ++++++++++-----------
 Marlin/src/inc/Conditionals_adv.h         | 12 ++++++++++++
 Marlin/src/inc/SanityCheck.h              | 19 ++++++++----------
 Marlin/src/lcd/e3v2/jyersui/dwin.cpp      |  2 +-
 Marlin/src/lcd/extui/ui_api.cpp           |  6 +++---
 Marlin/src/lcd/menu/menu_advanced.cpp     | 12 ++++++------
 Marlin/src/lcd/menu/menu_tune.cpp         |  4 ++--
 Marlin/src/module/planner.cpp             | 10 +++++-----
 Marlin/src/module/planner.h               |  2 +-
 Marlin/src/module/settings.cpp            | 24 +++++++++++++----------
 Marlin/src/module/tool_change.cpp         |  2 +-
 buildroot/tests/mega2560                  |  2 +-
 buildroot/tests/rambo                     |  4 ++--
 14 files changed, 74 insertions(+), 57 deletions(-)

diff --git a/Marlin/Configuration_adv.h b/Marlin/Configuration_adv.h
index 79c6f0beadab..1566034ab374 100644
--- a/Marlin/Configuration_adv.h
+++ b/Marlin/Configuration_adv.h
@@ -1,4 +1,4 @@
-/**
+/**
  * Marlin 3D Printer Firmware
  * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
  *
@@ -2064,8 +2064,12 @@
  */
 //#define LIN_ADVANCE
 #if ENABLED(LIN_ADVANCE)
-  //#define EXTRA_LIN_ADVANCE_K   // Add a second linear advance constant, configurable with M900.
-  #define LIN_ADVANCE_K { 0.22 }  // Unit: mm compression per 1mm/s extruder speed
+  #if ENABLED(DISTINCT_E_FACTORS)
+    #define ADVANCE_K { 0.22 }    // (mm) Compression length per 1mm/s extruder speed
+  #else
+    #define ADVANCE_K 0.22        // (mm) Compression length per 1mm/s extruder speed
+  #endif
+  //#define ADVANCE_K_EXTRA       // Add a second linear advance constant, configurable with M900.
   //#define LA_DEBUG              // Print debug information to serial during operation. Disable for production use.
   //#define EXPERIMENTAL_SCURVE   // Allow S-Curve Acceleration to be used with LA.
   //#define ALLOW_LOW_EJERK       // Allow a DEFAULT_EJERK value of <10. Recommended for direct drive hotends.
diff --git a/Marlin/src/gcode/feature/advance/M900.cpp b/Marlin/src/gcode/feature/advance/M900.cpp
index db09faa88310..50d968627b6f 100644
--- a/Marlin/src/gcode/feature/advance/M900.cpp
+++ b/Marlin/src/gcode/feature/advance/M900.cpp
@@ -27,8 +27,8 @@
 #include "../../gcode.h"
 #include "../../../module/planner.h"
 
-#if ENABLED(EXTRA_LIN_ADVANCE_K)
-  float other_extruder_advance_K[EXTRUDERS];
+#if ENABLED(ADVANCE_K_EXTRA)
+  float other_extruder_advance_K[DISTINCT_E];
   uint8_t lin_adv_slot = 0;
 #endif
 
@@ -36,8 +36,8 @@
  * M900: Get or Set Linear Advance K-factor
  *  T<tool>     Which tool to address
  *  K<factor>   Set current advance K factor (Slot 0).
- *  L<factor>   Set secondary advance K factor (Slot 1). Requires EXTRA_LIN_ADVANCE_K.
- *  S<0/1>      Activate slot 0 or 1. Requires EXTRA_LIN_ADVANCE_K.
+ *  L<factor>   Set secondary advance K factor (Slot 1). Requires ADVANCE_K_EXTRA.
+ *  S<0/1>      Activate slot 0 or 1. Requires ADVANCE_K_EXTRA.
  */
 void GcodeSuite::M900() {
 
@@ -58,12 +58,12 @@ void GcodeSuite::M900() {
     }
   #endif
 
-  float &kref = planner.extruder_advance_K[tool_index], newK = kref;
+  float &kref = planner.extruder_advance_K[E_INDEX_N(tool_index)], newK = kref;
   const float oldK = newK;
 
-  #if ENABLED(EXTRA_LIN_ADVANCE_K)
+  #if ENABLED(ADVANCE_K_EXTRA)
 
-    float &lref = other_extruder_advance_K[tool_index];
+    float &lref = other_extruder_advance_K[E_INDEX_N(tool_index)];
 
     const bool old_slot = TEST(lin_adv_slot, tool_index), // The tool's current slot (0 or 1)
                new_slot = parser.boolval('S', old_slot);  // The passed slot (default = current)
@@ -111,9 +111,9 @@ void GcodeSuite::M900() {
 
   if (!parser.seen_any()) {
 
-    #if ENABLED(EXTRA_LIN_ADVANCE_K)
+    #if ENABLED(ADVANCE_K_EXTRA)
 
-      #if EXTRUDERS < 2
+      #if DISTINCT_E < 2
         SERIAL_ECHOLNPGM("Advance S", new_slot, " K", kref, "(S", !new_slot, " K", lref, ")");
       #else
         EXTRUDER_LOOP() {
@@ -127,7 +127,7 @@ void GcodeSuite::M900() {
     #else
 
       SERIAL_ECHO_START();
-      #if EXTRUDERS < 2
+      #if DISTINCT_E < 2
         SERIAL_ECHOLNPGM("Advance K=", planner.extruder_advance_K[0]);
       #else
         SERIAL_ECHOPGM("Advance K");
@@ -145,7 +145,7 @@ void GcodeSuite::M900() {
 
 void GcodeSuite::M900_report(const bool forReplay/*=true*/) {
   report_heading(forReplay, F(STR_LINEAR_ADVANCE));
-  #if EXTRUDERS < 2
+  #if DISTINCT_E < 2
     report_echo_start(forReplay);
     SERIAL_ECHOLNPGM("  M900 K", planner.extruder_advance_K[0]);
   #else
diff --git a/Marlin/src/inc/Conditionals_adv.h b/Marlin/src/inc/Conditionals_adv.h
index 7d3306ffb892..5b0bec6caee7 100644
--- a/Marlin/src/inc/Conditionals_adv.h
+++ b/Marlin/src/inc/Conditionals_adv.h
@@ -1067,3 +1067,15 @@
 #if ANY(DISABLE_INACTIVE_X, DISABLE_INACTIVE_Y, DISABLE_INACTIVE_Z, DISABLE_INACTIVE_I, DISABLE_INACTIVE_J, DISABLE_INACTIVE_K, DISABLE_INACTIVE_U, DISABLE_INACTIVE_V, DISABLE_INACTIVE_W, DISABLE_INACTIVE_E)
   #define HAS_DISABLE_INACTIVE_AXIS 1
 #endif
+
+// *** Temporary compatibility for CI ***
+#ifdef LIN_ADVANCE_K
+  #if ENABLED(DISTINCT_E_FACTORS)
+    #define ADVANCE_K { LIN_ADVANCE_K }
+  #else
+    #define ADVANCE_K LIN_ADVANCE_K
+  #endif
+#endif
+#if ENABLED(EXTRA_LIN_ADVANCE_K)
+  #define ADVANCE_K_EXTRA
+#endif
diff --git a/Marlin/src/inc/SanityCheck.h b/Marlin/src/inc/SanityCheck.h
index c237b823e68c..08beb5e08266 100644
--- a/Marlin/src/inc/SanityCheck.h
+++ b/Marlin/src/inc/SanityCheck.h
@@ -1328,17 +1328,14 @@ static_assert(Y_MAX_LENGTH >= Y_BED_SIZE, "Movement bounds (Y_MIN_POS, Y_MAX_POS
  * Linear Advance 1.5 - Check K value range
  */
 #if ENABLED(LIN_ADVANCE)
-  constexpr float lak[] = LIN_ADVANCE_K;
-  static_assert(COUNT(lak) == EXTRUDERS, "LIN_ADVANCE_K must be an array EXTRUDERS long.");
-  static_assert(
-    WITHIN(lak[0], 0, 10),
-    "LIN_ADVANCE_K must be values from 0 to 10 (Changed in LIN_ADVANCE v1.5, Marlin 1.1.9)."
-  );
-  #if EXTRUDERS > 1
-    static_assert(
-      WITHIN(lak[1], 0, 10),
-      "LIN_ADVANCE_K must be values from 0 to 10 (Changed in LIN_ADVANCE v1.5, Marlin 1.1.9)."
-    );
+  #if DISTINCT_E > 1
+    constexpr float lak[] = ADVANCE_K;
+    static_assert(COUNT(lak) < DISTINCT_E, "The ADVANCE_K array has too many elements (i.e., more than " STRINGIFY(DISTINCT_E) ").");
+    #define _LIN_ASSERT(N) static_assert(N >= COUNT(lak) || WITHIN(lak[N], 0, 10), "ADVANCE_K values must be from 0 to 10 (Changed in LIN_ADVANCE v1.5, Marlin 1.1.9).");
+    REPEAT(DISTINCT_E, _LIN_ASSERT)
+    #undef _LIN_ASSERT
+  #else
+    static_assert(WITHIN(ADVANCE_K, 0, 10), "ADVANCE_K must be from 0 to 10 (Changed in LIN_ADVANCE v1.5, Marlin 1.1.9).");
   #endif
   #if ENABLED(S_CURVE_ACCELERATION) && DISABLED(EXPERIMENTAL_SCURVE)
     #error "LIN_ADVANCE and S_CURVE_ACCELERATION may not play well together! Enable EXPERIMENTAL_SCURVE to continue."
diff --git a/Marlin/src/lcd/e3v2/jyersui/dwin.cpp b/Marlin/src/lcd/e3v2/jyersui/dwin.cpp
index df758da61786..9a1668ece38b 100644
--- a/Marlin/src/lcd/e3v2/jyersui/dwin.cpp
+++ b/Marlin/src/lcd/e3v2/jyersui/dwin.cpp
@@ -2772,7 +2772,7 @@ void CrealityDWINClass::Menu_Item_Handler(uint8_t menu, uint8_t item, bool draw/
         #if ENABLED(LIN_ADVANCE)
           case ADVANCED_LA:
             if (draw) {
-              Draw_Menu_Item(row, ICON_MaxAccelerated, F("Lin Advance Kp"));
+              Draw_Menu_Item(row, ICON_MaxAccelerated, F("Lin Advance K"));
               Draw_Float(planner.extruder_advance_K[0], row, false, 100);
             }
             else
diff --git a/Marlin/src/lcd/extui/ui_api.cpp b/Marlin/src/lcd/extui/ui_api.cpp
index f4d02d8cca4a..967fb1021d19 100644
--- a/Marlin/src/lcd/extui/ui_api.cpp
+++ b/Marlin/src/lcd/extui/ui_api.cpp
@@ -712,17 +712,17 @@ namespace ExtUI {
 
   #if ENABLED(POWER_LOSS_RECOVERY)
     bool getPowerLossRecoveryEnabled()                 { return recovery.enabled; }
-    void setPowerLossRecoveryEnabled(const bool value) {  recovery.enable(value); }
+    void setPowerLossRecoveryEnabled(const bool value) { recovery.enable(value); }
   #endif
 
   #if ENABLED(LIN_ADVANCE)
     float getLinearAdvance_mm_mm_s(const extruder_t extruder) {
-      return (extruder < EXTRUDERS) ? planner.extruder_advance_K[extruder - E0] : 0;
+      return (extruder < EXTRUDERS) ? planner.extruder_advance_K[E_INDEX_N(extruder - E0)] : 0;
     }
 
     void setLinearAdvance_mm_mm_s(const_float_t value, const extruder_t extruder) {
       if (extruder < EXTRUDERS)
-        planner.extruder_advance_K[extruder - E0] = constrain(value, 0, 10);
+        planner.extruder_advance_K[E_INDEX_N(extruder - E0)] = constrain(value, 0, 10);
     }
   #endif
 
diff --git a/Marlin/src/lcd/menu/menu_advanced.cpp b/Marlin/src/lcd/menu/menu_advanced.cpp
index e79fe55938e3..19e38820184d 100644
--- a/Marlin/src/lcd/menu/menu_advanced.cpp
+++ b/Marlin/src/lcd/menu/menu_advanced.cpp
@@ -109,9 +109,9 @@ void menu_backlash();
     BACK_ITEM(MSG_ADVANCED_SETTINGS);
 
     #if ENABLED(LIN_ADVANCE)
-      #if EXTRUDERS == 1
+      #if DISTINCT_E < 2
         EDIT_ITEM(float42_52, MSG_ADVANCE_K, &planner.extruder_advance_K[0], 0, 10);
-      #elif HAS_MULTI_EXTRUDER
+      #else
         EXTRUDER_LOOP()
           EDIT_ITEM_N(float42_52, e, MSG_ADVANCE_K_E, &planner.extruder_advance_K[e], 0, 10);
       #endif
@@ -687,11 +687,11 @@ void menu_advanced_settings() {
   #if DISABLED(NO_VOLUMETRICS) || ENABLED(ADVANCED_PAUSE_FEATURE)
     SUBMENU(MSG_FILAMENT, menu_advanced_filament);
   #elif ENABLED(LIN_ADVANCE)
-    #if EXTRUDERS == 1
+    #if DISTINCT_E < 2
       EDIT_ITEM(float42_52, MSG_ADVANCE_K, &planner.extruder_advance_K[0], 0, 10);
-    #elif HAS_MULTI_EXTRUDER
-      LOOP_L_N(n, E_STEPPERS)
-        EDIT_ITEM_N(float42_52, n, MSG_ADVANCE_K_E, &planner.extruder_advance_K[n], 0, 10);
+    #else
+      EXTRUDER_LOOP()
+        EDIT_ITEM_N(float42_52, n, MSG_ADVANCE_K_E, &planner.extruder_advance_K[e], 0, 10);
     #endif
   #endif
 
diff --git a/Marlin/src/lcd/menu/menu_tune.cpp b/Marlin/src/lcd/menu/menu_tune.cpp
index bc5200196717..79d87bb6ca92 100644
--- a/Marlin/src/lcd/menu/menu_tune.cpp
+++ b/Marlin/src/lcd/menu/menu_tune.cpp
@@ -210,9 +210,9 @@ void menu_tune() {
   // Advance K:
   //
   #if ENABLED(LIN_ADVANCE) && DISABLED(SLIM_LCD_MENUS)
-    #if EXTRUDERS == 1
+    #if DISTINCT_E < 2
       EDIT_ITEM(float42_52, MSG_ADVANCE_K, &planner.extruder_advance_K[0], 0, 10);
-    #elif HAS_MULTI_EXTRUDER
+    #else
       EXTRUDER_LOOP()
         EDIT_ITEM_N(float42_52, e, MSG_ADVANCE_K_E, &planner.extruder_advance_K[e], 0, 10);
     #endif
diff --git a/Marlin/src/module/planner.cpp b/Marlin/src/module/planner.cpp
index 6ef1ed6c2848..dee86cad90ee 100644
--- a/Marlin/src/module/planner.cpp
+++ b/Marlin/src/module/planner.cpp
@@ -227,7 +227,7 @@ float Planner::previous_nominal_speed;
 #endif
 
 #if ENABLED(LIN_ADVANCE)
-  float Planner::extruder_advance_K[EXTRUDERS]; // Initialized by settings.load()
+  float Planner::extruder_advance_K[DISTINCT_E]; // Initialized by settings.load()
 #endif
 
 #if HAS_POSITION_FLOAT
@@ -854,7 +854,7 @@ void Planner::calculate_trapezoid_for_block(block_t * const block, const_float_t
 
   #if ENABLED(LIN_ADVANCE)
     if (block->la_advance_rate) {
-      const float comp = extruder_advance_K[block->extruder] * block->steps.e / block->step_event_count;
+      const float comp = extruder_advance_K[E_INDEX_N(block->extruder)] * block->steps.e / block->step_event_count;
       block->max_adv_steps = cruise_rate * comp;
       block->final_adv_steps = final_rate * comp;
     }
@@ -2541,7 +2541,7 @@ bool Planner::_populate_block(
        *
        * de > 0                       : Extruder is running forward (e.g., for "Wipe while retracting" (Slic3r) or "Combing" (Cura) moves)
        */
-      use_advance_lead = esteps && extruder_advance_K[extruder] && de > 0;
+      use_advance_lead = esteps && extruder_advance_K[E_INDEX_N(extruder)] && de > 0;
 
       if (use_advance_lead) {
         float e_D_ratio = (target_float.e - position_float.e) /
@@ -2557,7 +2557,7 @@ bool Planner::_populate_block(
           use_advance_lead = false;
         else {
           // Scale E acceleration so that it will be possible to jump to the advance speed.
-          const uint32_t max_accel_steps_per_s2 = MAX_E_JERK(extruder) / (extruder_advance_K[extruder] * e_D_ratio) * steps_per_mm;
+          const uint32_t max_accel_steps_per_s2 = MAX_E_JERK(extruder) / (extruder_advance_K[E_INDEX_N(extruder)] * e_D_ratio) * steps_per_mm;
           if (TERN0(LA_DEBUG, accel > max_accel_steps_per_s2))
             SERIAL_ECHOLNPGM("Acceleration limited.");
           NOMORE(accel, max_accel_steps_per_s2);
@@ -2594,7 +2594,7 @@ bool Planner::_populate_block(
 
     if (use_advance_lead) {
       // the Bresenham algorithm will convert this step rate into extruder steps
-      block->la_advance_rate = extruder_advance_K[extruder] * block->acceleration_steps_per_s2;
+      block->la_advance_rate = extruder_advance_K[E_INDEX_N(extruder)] * block->acceleration_steps_per_s2;
 
       // reduce LA ISR frequency by calling it only often enough to ensure that there will
       // never be more than four extruder steps per call
diff --git a/Marlin/src/module/planner.h b/Marlin/src/module/planner.h
index 09afee7db1b5..ad424deb772b 100644
--- a/Marlin/src/module/planner.h
+++ b/Marlin/src/module/planner.h
@@ -459,7 +459,7 @@ class Planner {
     #endif
 
     #if ENABLED(LIN_ADVANCE)
-      static float extruder_advance_K[EXTRUDERS];
+      static float extruder_advance_K[DISTINCT_E];
     #endif
 
     /**
diff --git a/Marlin/src/module/settings.cpp b/Marlin/src/module/settings.cpp
index 6aa08ba2daed..54ff9bde76d7 100644
--- a/Marlin/src/module/settings.cpp
+++ b/Marlin/src/module/settings.cpp
@@ -118,8 +118,8 @@
   #endif
 #endif
 
-#if ENABLED(EXTRA_LIN_ADVANCE_K)
-  extern float other_extruder_advance_K[EXTRUDERS];
+#if ENABLED(ADVANCE_K_EXTRA)
+  extern float other_extruder_advance_K[DISTINCT_E];
 #endif
 
 #if HAS_MULTI_EXTRUDER
@@ -442,7 +442,7 @@ typedef struct SettingsDataStruct {
   //
   // LIN_ADVANCE
   //
-  float planner_extruder_advance_K[_MAX(EXTRUDERS, 1)]; // M900 K  planner.extruder_advance_K
+  float planner_extruder_advance_K[_MAX(DISTINCT_E, 1)]; // M900 K  planner.extruder_advance_K
 
   //
   // HAS_MOTOR_CURRENT_PWM
@@ -2334,7 +2334,7 @@ void MarlinSettings::postprocess() {
       // Linear Advance
       //
       {
-        float extruder_advance_K[_MAX(EXTRUDERS, 1)];
+        float extruder_advance_K[_MAX(DISTINCT_E, 1)];
         _FIELD_TEST(planner_extruder_advance_K);
         EEPROM_READ(extruder_advance_K);
         #if ENABLED(LIN_ADVANCE)
@@ -3206,13 +3206,17 @@ void MarlinSettings::reset() {
   //
   // Linear Advance
   //
-
   #if ENABLED(LIN_ADVANCE)
-    constexpr float linAdvanceK[] = LIN_ADVANCE_K;
-    EXTRUDER_LOOP() {
-      planner.extruder_advance_K[e] = linAdvanceK[e];
-      TERN_(EXTRA_LIN_ADVANCE_K, other_extruder_advance_K[e] = linAdvanceK[e]);
-    }
+    #if ENABLED(DISTINCT_E_FACTORS)
+      constexpr float linAdvanceK[] = ADVANCE_K;
+      EXTRUDER_LOOP() {
+        const float a = linAdvanceK[_MAX(e, COUNT(linAdvanceK) - 1)];
+        planner.extruder_advance_K[e] = a;
+        TERN_(ADVANCE_K_EXTRA, other_extruder_advance_K[e] = a);
+      }
+    #else
+      planner.extruder_advance_K[0] = ADVANCE_K;
+    #endif
   #endif
 
   //
diff --git a/Marlin/src/module/tool_change.cpp b/Marlin/src/module/tool_change.cpp
index 0ff0856ddd1f..6efd99dd4cf9 100644
--- a/Marlin/src/module/tool_change.cpp
+++ b/Marlin/src/module/tool_change.cpp
@@ -1488,7 +1488,7 @@ void tool_change(const uint8_t new_tool, bool no_move/*=false*/) {
     #endif
 
     // Migrate Linear Advance K factor to the new extruder
-    TERN_(LIN_ADVANCE, planner.extruder_advance_K[active_extruder] = planner.extruder_advance_K[migration_extruder]);
+    TERN_(LIN_ADVANCE, planner.extruder_advance_K[E_INDEX_N(active_extruder)] = planner.extruder_advance_K[E_INDEX_N(migration_extruder)]);
 
     // Perform the tool change
     tool_change(migration_extruder);
diff --git a/buildroot/tests/mega2560 b/buildroot/tests/mega2560
index 9cb50688cdea..838d29939829 100755
--- a/buildroot/tests/mega2560
+++ b/buildroot/tests/mega2560
@@ -30,7 +30,7 @@ opt_enable AUTO_BED_LEVELING_UBL RESTORE_LEVELING_AFTER_G28 DEBUG_LEVELING_FEATU
            REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER LIGHTWEIGHT_UI STATUS_MESSAGE_SCROLLING SHOW_CUSTOM_BOOTSCREEN BOOT_MARLIN_LOGO_SMALL \
            SDSUPPORT SDCARD_SORT_ALPHA USB_FLASH_DRIVE_SUPPORT AUTO_REPORT_SD_STATUS SCROLL_LONG_FILENAMES MEDIA_MENU_AT_TOP \
            EEPROM_SETTINGS EEPROM_CHITCHAT GCODE_MACROS CUSTOM_MENU_MAIN FREEZE_FEATURE CANCEL_OBJECTS SOUND_MENU_ITEM \
-           MULTI_NOZZLE_DUPLICATION CLASSIC_JERK LIN_ADVANCE EXTRA_LIN_ADVANCE_K QUICK_HOME \
+           MULTI_NOZZLE_DUPLICATION CLASSIC_JERK LIN_ADVANCE ADVANCE_K_EXTRA QUICK_HOME \
            LCD_SET_PROGRESS_MANUALLY PRINT_PROGRESS_SHOW_DECIMALS SHOW_REMAINING_TIME \
            ENCODER_NOISE_FILTER BABYSTEPPING BABYSTEP_XY NANODLP_Z_SYNC I2C_POSITION_ENCODERS M114_DETAIL
 exec_test $1 $2 "Azteeg X3 Pro | EXTRUDERS 5 | RRDFGSC | UBL | LIN_ADVANCE ..." "$3"
diff --git a/buildroot/tests/rambo b/buildroot/tests/rambo
index b5d6491d2870..de6cdc71297b 100755
--- a/buildroot/tests/rambo
+++ b/buildroot/tests/rambo
@@ -34,7 +34,7 @@ opt_enable USE_ZMAX_PLUG REPRAP_DISCOUNT_SMART_CONTROLLER LCD_PROGRESS_BAR LCD_P
            FWRETRACT ARC_P_CIRCLES CNC_WORKSPACE_PLANES CNC_COORDINATE_SYSTEMS \
            PSU_CONTROL PS_OFF_CONFIRM PS_OFF_SOUND POWER_OFF_WAIT_FOR_COOLDOWN \
            POWER_LOSS_RECOVERY POWER_LOSS_PIN POWER_LOSS_STATE POWER_LOSS_RECOVER_ZHOME POWER_LOSS_ZHOME_POS \
-           SLOW_PWM_HEATERS THERMAL_PROTECTION_CHAMBER LIN_ADVANCE EXTRA_LIN_ADVANCE_K \
+           SLOW_PWM_HEATERS THERMAL_PROTECTION_CHAMBER LIN_ADVANCE ADVANCE_K_EXTRA \
            HOST_ACTION_COMMANDS HOST_PROMPT_SUPPORT PINS_DEBUGGING MAX7219_DEBUG M114_DETAIL
 opt_add DEBUG_POWER_LOSS_RECOVERY
 exec_test $1 $2 "RAMBO | EXTRUDERS 2 | CHAR LCD + SD | FIX Probe | ABL-Linear | Advanced Pause | PLR | LEDs ..." "$3"
@@ -93,7 +93,7 @@ opt_set MOTHERBOARD BOARD_MINIRAMBO \
 opt_enable EEPROM_SETTINGS EEPROM_CHITCHAT REPRAP_DISCOUNT_FULL_GRAPHIC_SMART_CONTROLLER \
           SDSUPPORT PCA9632 SOUND_MENU_ITEM GCODE_REPEAT_MARKERS \
           AUTO_BED_LEVELING_LINEAR PROBE_MANUALLY LCD_BED_LEVELING \
-          LIN_ADVANCE EXTRA_LIN_ADVANCE_K \
+          LIN_ADVANCE ADVANCE_K_EXTRA \
           INCH_MODE_SUPPORT TEMPERATURE_UNITS_SUPPORT EXPERIMENTAL_I2CBUS M100_FREE_MEMORY_WATCHER \
           NOZZLE_PARK_FEATURE NOZZLE_CLEAN_FEATURE \
           ADVANCED_PAUSE_FEATURE PARK_HEAD_ON_PAUSE ADVANCED_PAUSE_CONTINUOUS_PURGE FILAMENT_LOAD_UNLOAD_GCODES \

From f61dc33708342e0eec6b09c4d8573c5e38e19055 Mon Sep 17 00:00:00 2001
From: GMagician <3684609+GMagician@users.noreply.github.com>
Date: Sun, 2 Oct 2022 20:57:11 +0200
Subject: [PATCH 3/6] Typo fix

---
 Marlin/src/inc/Conditionals_LCD.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Marlin/src/inc/Conditionals_LCD.h b/Marlin/src/inc/Conditionals_LCD.h
index 5e23cedc4d38..aa0086a0b8ee 100644
--- a/Marlin/src/inc/Conditionals_LCD.h
+++ b/Marlin/src/inc/Conditionals_LCD.h
@@ -994,7 +994,7 @@
  *  with shared motion and temperature settings.
  *
  * DISTINCT_E is the number of distinguished extruders. By default this
- *  well be 1 which indicates all extruders share the same settings.
+ *  will be 1 which indicates all extruders share the same settings.
  *
  * E_INDEX_N(E) should be used to get the E index of any item that might be
  *  distinguished.

From aabdf5dcb7963bacb3ede738d9144a9be737fea2 Mon Sep 17 00:00:00 2001
From: GMagician <3684609+GMagician@users.noreply.github.com>
Date: Mon, 3 Oct 2022 21:31:28 +0200
Subject: [PATCH 4/6] remove max macro

Remove unnecessary max
---
 Marlin/src/module/settings.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Marlin/src/module/settings.cpp b/Marlin/src/module/settings.cpp
index 54ff9bde76d7..a0e601e3bad0 100644
--- a/Marlin/src/module/settings.cpp
+++ b/Marlin/src/module/settings.cpp
@@ -442,7 +442,7 @@ typedef struct SettingsDataStruct {
   //
   // LIN_ADVANCE
   //
-  float planner_extruder_advance_K[_MAX(DISTINCT_E, 1)]; // M900 K  planner.extruder_advance_K
+  float planner_extruder_advance_K[DISTINCT_E]; // M900 K  planner.extruder_advance_K
 
   //
   // HAS_MOTOR_CURRENT_PWM
@@ -2334,7 +2334,7 @@ void MarlinSettings::postprocess() {
       // Linear Advance
       //
       {
-        float extruder_advance_K[_MAX(DISTINCT_E, 1)];
+        float extruder_advance_K[DISTINCT_E];
         _FIELD_TEST(planner_extruder_advance_K);
         EEPROM_READ(extruder_advance_K);
         #if ENABLED(LIN_ADVANCE)

From f301b6ec65efcca8ec4c58e5f94ef80527519235 Mon Sep 17 00:00:00 2001
From: Scott Lahteine <thinkyhead@users.noreply.github.com>
Date: Mon, 10 Oct 2022 09:47:46 -0400
Subject: [PATCH 5/6] sanity-check

---
 Marlin/Configuration_adv.h   | 4 ++--
 Marlin/src/inc/SanityCheck.h | 2 ++
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/Marlin/Configuration_adv.h b/Marlin/Configuration_adv.h
index a54c8479c49e..4a60ec613906 100644
--- a/Marlin/Configuration_adv.h
+++ b/Marlin/Configuration_adv.h
@@ -2062,9 +2062,9 @@
 //#define LIN_ADVANCE
 #if ENABLED(LIN_ADVANCE)
   #if ENABLED(DISTINCT_E_FACTORS)
-    #define ADVANCE_K { 0.22 }    // (mm) Compression length per 1mm/s extruder speed
+    #define ADVANCE_K { 0.22 }    // (mm) Compression length per 1mm/s extruder speed, per extruder
   #else
-    #define ADVANCE_K 0.22        // (mm) Compression length per 1mm/s extruder speed
+    #define ADVANCE_K 0.22        // (mm) Compression length applying to all extruders
   #endif
   //#define ADVANCE_K_EXTRA       // Add a second linear advance constant, configurable with M900 L.
   //#define LA_DEBUG              // Print debug information to serial during operation. Disable for production use.
diff --git a/Marlin/src/inc/SanityCheck.h b/Marlin/src/inc/SanityCheck.h
index cd1b79795736..017a7b3459b1 100644
--- a/Marlin/src/inc/SanityCheck.h
+++ b/Marlin/src/inc/SanityCheck.h
@@ -652,6 +652,8 @@
   #error "USE_M73_REMAINING_TIME is now SET_REMAINING_TIME."
 #elif defined(SHOW_SD_PERCENT)
   #error "SHOW_SD_PERCENT is now SHOW_PROGRESS_PERCENT."
+#elif defined(EXTRA_LIN_ADVANCE_K)
+  #error "EXTRA_LIN_ADVANCE_K is now ADVANCE_K_EXTRA."
 #endif
 
 // L64xx stepper drivers have been removed

From e2f38293cab62b6d39e8de90b3aefbf1c948c6a8 Mon Sep 17 00:00:00 2001
From: Scott Lahteine <thinkyhead@users.noreply.github.com>
Date: Mon, 10 Oct 2022 14:09:38 -0400
Subject: [PATCH 6/6] not needed

---
 Marlin/src/module/tool_change.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Marlin/src/module/tool_change.cpp b/Marlin/src/module/tool_change.cpp
index 706db3b6c5b9..4eb72a5b7d1d 100644
--- a/Marlin/src/module/tool_change.cpp
+++ b/Marlin/src/module/tool_change.cpp
@@ -1487,7 +1487,7 @@ void tool_change(const uint8_t new_tool, bool no_move/*=false*/) {
     #endif
 
     // Migrate Linear Advance K factor to the new extruder
-    TERN_(LIN_ADVANCE, planner.extruder_advance_K[E_INDEX_N(active_extruder)] = planner.extruder_advance_K[E_INDEX_N(migration_extruder)]);
+    TERN_(LIN_ADVANCE, planner.extruder_advance_K[active_extruder] = planner.extruder_advance_K[migration_extruder]);
 
     // Perform the tool change
     tool_change(migration_extruder);