From 38560378fcb99bcdb4b889f3b8e08c7dc5abe366 Mon Sep 17 00:00:00 2001
From: engrenage <32837871+petaflot@users.noreply.github.com>
Date: Thu, 25 Jan 2024 21:24:57 +0100
Subject: [PATCH] =?UTF-8?q?=F0=9F=94=A7=20Allow=20float=20Z=5FPROBE=5FLOW?=
 =?UTF-8?q?=5FPOINT=20(#26711)?=
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---
 Marlin/src/inc/SanityCheck.h | 4 +---
 Marlin/src/module/probe.cpp  | 4 ++++
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/Marlin/src/inc/SanityCheck.h b/Marlin/src/inc/SanityCheck.h
index 5a22accc6d..ccbf5c6705 100644
--- a/Marlin/src/inc/SanityCheck.h
+++ b/Marlin/src/inc/SanityCheck.h
@@ -1508,9 +1508,7 @@ static_assert(NUM_SERVOS <= NUM_SERVO_PLUGS, "NUM_SERVOS (or some servo index) i
     #endif
   #endif
 
-  #if Z_PROBE_LOW_POINT > 0
-    #error "Z_PROBE_LOW_POINT must be less than or equal to 0."
-  #endif
+  static_assert(Z_PROBE_LOW_POINT <= 0, "Z_PROBE_LOW_POINT must be less than or equal to 0.");
 
   #if ENABLED(PROBE_ACTIVATION_SWITCH)
     #ifndef PROBE_ACTIVATION_SWITCH_STATE
diff --git a/Marlin/src/module/probe.cpp b/Marlin/src/module/probe.cpp
index ee9e9b34ac..2fec098b8a 100644
--- a/Marlin/src/module/probe.cpp
+++ b/Marlin/src/module/probe.cpp
@@ -1010,6 +1010,10 @@ float Probe::probe_at_point(const_float_t rx, const_float_t ry, const ProbePtRai
 
     // If any error occurred stow the probe and set an alert
     if (isnan(measured_z)) {
+      // TODO: Disable steppers (unless G29_RETRY_AND_RECOVER or G29_HALT_ON_FAILURE are set).
+      // Something definitely went wrong at this point, so it might be a good idea to release the steppers.
+      // The user may want to quickly move the carriage or bed by hand to avoid bed damage from the (hot) nozzle.
+      // This would also benefit from the contemplated "Audio Alerts" feature.
       stow();
       LCD_MESSAGE(MSG_LCD_PROBING_FAILED);
       #if DISABLED(G29_RETRY_AND_RECOVER)