From ee26fd0e0559d7f2d86b11b5552eaf9c9ff3174c Mon Sep 17 00:00:00 2001
From: tombrazier <68918209+tombrazier@users.noreply.github.com>
Date: Mon, 25 Oct 2021 22:29:40 +0100
Subject: [PATCH] =?UTF-8?q?=F0=9F=9A=B8=20Default=20T0=20for=20M569,=20M90?=
 =?UTF-8?q?6,=20M913=20(#23020)?=
MIME-Version: 1.0
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---
 Marlin/src/gcode/feature/L6470/M906.cpp         | 2 +-
 Marlin/src/gcode/feature/trinamic/M569.cpp      | 2 +-
 Marlin/src/gcode/feature/trinamic/M906.cpp      | 2 +-
 Marlin/src/gcode/feature/trinamic/M911-M914.cpp | 2 +-
 Marlin/src/gcode/gcode.cpp                      | 9 +++++----
 Marlin/src/gcode/gcode.h                        | 2 +-
 6 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/Marlin/src/gcode/feature/L6470/M906.cpp b/Marlin/src/gcode/feature/L6470/M906.cpp
index 2ab13f5b5d58..bab355fe38c2 100644
--- a/Marlin/src/gcode/feature/L6470/M906.cpp
+++ b/Marlin/src/gcode/feature/L6470/M906.cpp
@@ -280,7 +280,7 @@ void GcodeSuite::M906() {
 
       #if E_STEPPERS
         case E_AXIS: {
-          const int8_t target_e_stepper = get_target_e_stepper_from_command();
+          const int8_t target_e_stepper = get_target_e_stepper_from_command(0);
           if (target_e_stepper < 0) return;
           switch (target_e_stepper) {
             #if AXIS_IS_L64XX(E0)
diff --git a/Marlin/src/gcode/feature/trinamic/M569.cpp b/Marlin/src/gcode/feature/trinamic/M569.cpp
index 5cadd2d45ea7..05730eabfdd7 100644
--- a/Marlin/src/gcode/feature/trinamic/M569.cpp
+++ b/Marlin/src/gcode/feature/trinamic/M569.cpp
@@ -133,7 +133,7 @@ static void say_stealth_status() {
  */
 void GcodeSuite::M569() {
   if (parser.seen('S'))
-    set_stealth_status(parser.value_bool(), get_target_e_stepper_from_command());
+    set_stealth_status(parser.value_bool(), get_target_e_stepper_from_command(0));
   else
     say_stealth_status();
 }
diff --git a/Marlin/src/gcode/feature/trinamic/M906.cpp b/Marlin/src/gcode/feature/trinamic/M906.cpp
index 48db266c72af..c3e12a4f92c1 100644
--- a/Marlin/src/gcode/feature/trinamic/M906.cpp
+++ b/Marlin/src/gcode/feature/trinamic/M906.cpp
@@ -104,7 +104,7 @@ void GcodeSuite::M906() {
 
       #if E_STEPPERS
         case E_AXIS: {
-          const int8_t target_e_stepper = get_target_e_stepper_from_command();
+          const int8_t target_e_stepper = get_target_e_stepper_from_command(0);
           if (target_e_stepper < 0) return;
           switch (target_e_stepper) {
             #if AXIS_IS_TMC(E0)
diff --git a/Marlin/src/gcode/feature/trinamic/M911-M914.cpp b/Marlin/src/gcode/feature/trinamic/M911-M914.cpp
index 58702c603f41..f15343484a93 100644
--- a/Marlin/src/gcode/feature/trinamic/M911-M914.cpp
+++ b/Marlin/src/gcode/feature/trinamic/M911-M914.cpp
@@ -268,7 +268,7 @@
           break;
         #if E_STEPPERS
           case E_AXIS: {
-            const int8_t target_e_stepper = get_target_e_stepper_from_command();
+            const int8_t target_e_stepper = get_target_e_stepper_from_command(0);
             if (target_e_stepper < 0) return;
             switch (target_e_stepper) {
               TERN_(E0_HAS_STEALTHCHOP, case 0: TMC_SET_PWMTHRS_E(0); break;)
diff --git a/Marlin/src/gcode/gcode.cpp b/Marlin/src/gcode/gcode.cpp
index 888dbe7027eb..126ceadb3b9a 100644
--- a/Marlin/src/gcode/gcode.cpp
+++ b/Marlin/src/gcode/gcode.cpp
@@ -137,11 +137,12 @@ int8_t GcodeSuite::get_target_extruder_from_command() {
 }
 
 /**
- * Get the target e stepper from the T parameter
- * Return -1 if the T parameter is out of range or unspecified
+ * Get the target E stepper from the 'T' parameter.
+ * If there is no 'T' parameter then dval will be substituted.
+ * Returns -1 if the resulting E stepper index is out of range.
  */
-int8_t GcodeSuite::get_target_e_stepper_from_command() {
-  const int8_t e = parser.intval('T', -1);
+int8_t GcodeSuite::get_target_e_stepper_from_command(const int8_t dval/*=-1*/) {
+  const int8_t e = parser.intval('T', dval);
   if (WITHIN(e, 0, E_STEPPERS - 1)) return e;
 
   SERIAL_ECHO_START();
diff --git a/Marlin/src/gcode/gcode.h b/Marlin/src/gcode/gcode.h
index 4a3c865a4fd8..2173c5cab191 100644
--- a/Marlin/src/gcode/gcode.h
+++ b/Marlin/src/gcode/gcode.h
@@ -390,7 +390,7 @@ class GcodeSuite {
   static void say_units();
 
   static int8_t get_target_extruder_from_command();
-  static int8_t get_target_e_stepper_from_command();
+  static int8_t get_target_e_stepper_from_command(const int8_t dval=-1);
   static void get_destination_from_command();
 
   static void process_parsed_command(const bool no_ok=false);