From 93394f1ff54678ca5965ef6116ddd1211e8f9314 Mon Sep 17 00:00:00 2001
From: Skruppy <skruppy@onmars.eu>
Date: Wed, 29 Oct 2025 03:01:17 +0100
Subject: [PATCH] =?UTF-8?q?=E2=9C=A8=20Use=20TMC=20SoftwareSerial=20only?=
 =?UTF-8?q?=20if=20required=20(#28145)?=
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---
 Marlin/src/HAL/AVR/inc/SanityCheck.h | 2 +-
 Marlin/src/inc/Conditionals-5-post.h | 2 ++
 ini/features.ini                     | 3 ++-
 3 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/Marlin/src/HAL/AVR/inc/SanityCheck.h b/Marlin/src/HAL/AVR/inc/SanityCheck.h
index 85ee683685..08fe21d4f8 100644
--- a/Marlin/src/HAL/AVR/inc/SanityCheck.h
+++ b/Marlin/src/HAL/AVR/inc/SanityCheck.h
@@ -95,7 +95,7 @@
 /**
  * The Trinamic library includes SoftwareSerial.h, leading to a compile error.
  */
-#if ALL(HAS_TRINAMIC_CONFIG, ENDSTOP_INTERRUPTS_FEATURE)
+#if ALL(HAS_TMC_SW_SERIAL, ENDSTOP_INTERRUPTS_FEATURE)
   #error "TMCStepper includes SoftwareSerial.h which is incompatible with ENDSTOP_INTERRUPTS_FEATURE. Disable ENDSTOP_INTERRUPTS_FEATURE to continue."
 #endif
 
diff --git a/Marlin/src/inc/Conditionals-5-post.h b/Marlin/src/inc/Conditionals-5-post.h
index 67c0135d19..6e5fa8de6c 100644
--- a/Marlin/src/inc/Conditionals-5-post.h
+++ b/Marlin/src/inc/Conditionals-5-post.h
@@ -1867,6 +1867,8 @@
 #endif
 #if ANY_AXIS_HAS(SW_SERIAL)
   #define HAS_TMC_SW_SERIAL 1
+#elif HAS_TRINAMIC_CONFIG
+  #define HAS_TMC_WITHOUT_SW_SERIAL 1
 #endif
 #ifndef SERIAL_FLOAT_PRECISION
   #define SERIAL_FLOAT_PRECISION 2
diff --git a/ini/features.ini b/ini/features.ini
index 3799c2864c..c3fc6df537 100644
--- a/ini/features.ini
+++ b/ini/features.ini
@@ -20,8 +20,9 @@ MARLIN_TEST_BUILD                      = build_src_filter=+<src/tests>
 POSTMORTEM_DEBUGGING                   = build_src_filter=+<src/HAL/shared/cpu_exception> +<src/HAL/shared/backtrace>
                                          build_flags=-funwind-tables
 MKS_WIFI_MODULE                        = QRCode=https://github.com/makerbase-mks/QRCode/archive/261c5a696a.zip
-HAS_TRINAMIC_CONFIG                    = TMCStepper=https://github.com/MarlinFirmware/TMCStepper/archive/v0.8.8.zip
+HAS_TRINAMIC_CONFIG                    = TMCStepper=https://github.com/MarlinFirmware/TMCStepper/archive/v0.8.9.zip
                                          build_src_filter=+<src/module/stepper/trinamic.cpp> +<src/gcode/feature/trinamic/M122.cpp> +<src/gcode/feature/trinamic/M906.cpp> +<src/gcode/feature/trinamic/M911-M914.cpp> +<src/gcode/feature/trinamic/M919.cpp>
+HAS_TMC_WITHOUT_SW_SERIAL              = build_flags=-DTMCSTEPPER_SW_SERIAL=false
 HAS_STEPPER_CONTROL                    = build_src_filter=+<src/module/stepper/control.cpp>
 HAS_T(RINAMIC_CONFIG|MC_SPI)           = build_src_filter=+<src/feature/tmc_util.cpp>
 EDITABLE_HOMING_CURRENT                = build_src_filter=+<src/gcode/feature/trinamic/M920.cpp>