From 87d744995271945b814d9f4c84d3b791422c0c50 Mon Sep 17 00:00:00 2001
From: Scott Lahteine <thinkyhead@users.noreply.github.com>
Date: Wed, 8 Feb 2023 19:39:21 -0600
Subject: [PATCH] =?UTF-8?q?=F0=9F=A9=B9=20Use=20'M205=20D'=20when=20'B'=20?=
 =?UTF-8?q?is=20an=20axis?=
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---
 Marlin/src/gcode/config/M200-M205.cpp | 45 +++++++++++++++++----------
 1 file changed, 29 insertions(+), 16 deletions(-)

diff --git a/Marlin/src/gcode/config/M200-M205.cpp b/Marlin/src/gcode/config/M200-M205.cpp
index 87c1f2ce30..cda3177d93 100644
--- a/Marlin/src/gcode/config/M200-M205.cpp
+++ b/Marlin/src/gcode/config/M200-M205.cpp
@@ -221,9 +221,9 @@ void GcodeSuite::M203_report(const bool forReplay/*=true*/) {
 /**
  * M204: Set Accelerations in units/sec^2 (M204 P1200 R3000 T3000)
  *
- *    P = Printing moves
- *    R = Retract only (no X, Y, Z) moves
- *    T = Travel (non printing) moves
+ *    P<accel> Printing moves
+ *    R<accel> Retract only (no X, Y, Z) moves
+ *    T<accel> Travel (non printing) moves
  */
 void GcodeSuite::M204() {
   if (!parser.seen("PRST"))
@@ -247,24 +247,37 @@ void GcodeSuite::M204_report(const bool forReplay/*=true*/) {
   );
 }
 
+#if AXIS_COLLISION('B')
+  #define M205_MIN_SEG_TIME_PARAM 'D'
+  #define M205_MIN_SEG_TIME_STR "D"
+  #warning "Use 'M205 D' for Minimum Segment Time."
+#else
+  #define M205_MIN_SEG_TIME_PARAM 'B'
+  #define M205_MIN_SEG_TIME_STR "B"
+#endif
+
 /**
  * M205: Set Advanced Settings
  *
- *    B = Min Segment Time (µs)
- *    S = Min Feed Rate (units/s)
- *    T = Min Travel Feed Rate (units/s)
- *    X = Max X Jerk (units/sec^2)
- *    Y = Max Y Jerk (units/sec^2)
- *    Z = Max Z Jerk (units/sec^2)
- *    E = Max E Jerk (units/sec^2)
- *    J = Junction Deviation (mm) (If not using CLASSIC_JERK)
+ *    B<µs>          : Min Segment Time
+ *    S<units/s>     : Min Feed Rate
+ *    T<units/s>     : Min Travel Feed Rate
+ *
+ * With CLASSIC_JERK:
+ *    X<units/sec^2> : Max X Jerk
+ *    Y<units/sec^2> : Max Y Jerk
+ *    Z<units/sec^2> : Max Z Jerk
+ *               ... : etc
+ *    E<units/sec^2> : Max E Jerk
+ *
+ * Without CLASSIC_JERK:
+ *    J(mm)          : Junction Deviation
  */
 void GcodeSuite::M205() {
-  if (!parser.seen("BST" TERN_(HAS_JUNCTION_DEVIATION, "J") TERN_(HAS_CLASSIC_JERK, "XYZE")))
-    return M205_report();
+  if (!parser.seen_any()) return M205_report();
 
   //planner.synchronize();
-  if (parser.seenval('B')) planner.settings.min_segment_time_us = parser.value_ulong();
+  if (parser.seenval(M205_MIN_SEG_TIME_PARAM)) planner.settings.min_segment_time_us = parser.value_ulong();
   if (parser.seenval('S')) planner.settings.min_feedrate_mm_s = parser.value_linear_units();
   if (parser.seenval('T')) planner.settings.min_travel_feedrate_mm_s = parser.value_linear_units();
   #if HAS_JUNCTION_DEVIATION
@@ -304,7 +317,7 @@ void GcodeSuite::M205() {
 
 void GcodeSuite::M205_report(const bool forReplay/*=true*/) {
   report_heading_etc(forReplay, F(
-    "Advanced (B<min_segment_time_us> S<min_feedrate> T<min_travel_feedrate>"
+    "Advanced (" M205_MIN_SEG_TIME_STR "<min_segment_time_us> S<min_feedrate> T<min_travel_feedrate>"
     TERN_(HAS_JUNCTION_DEVIATION, " J<junc_dev>")
     #if HAS_CLASSIC_JERK
       NUM_AXIS_GANG(
@@ -317,7 +330,7 @@ void GcodeSuite::M205_report(const bool forReplay/*=true*/) {
     ")"
   ));
   SERIAL_ECHOLNPGM_P(
-      PSTR("  M205 B"), LINEAR_UNIT(planner.settings.min_segment_time_us)
+      PSTR("  M205 " M205_MIN_SEG_TIME_STR), LINEAR_UNIT(planner.settings.min_segment_time_us)
     , PSTR(" S"), LINEAR_UNIT(planner.settings.min_feedrate_mm_s)
     , SP_T_STR, LINEAR_UNIT(planner.settings.min_travel_feedrate_mm_s)
     #if HAS_JUNCTION_DEVIATION