From 2aaa6bcf63660fa3f413c35ef84733672413d693 Mon Sep 17 00:00:00 2001
From: Luca Toniolo <10792599+grandixximo@users.noreply.github.com>
Date: Mon, 9 Nov 2026 17:16:31 +1100
Subject: [PATCH] motion: read the 64-bit axis jog-counts without truncating

axis.L.jog-counts is a SINT pin, but the wheel jog read it with
hal_get_si32() while the previous count and the delta are 64-bit. When
the counts crossed 2^31 the delta came out near -2^32 for one cycle: the
target fell outside the limits and the jog was dropped, or with
jog-vel-mode the axis ran back by its stopping distance. The joint wheel
jog already reads its counts with hal_get_sint().

The jogwheel-axis test now jogs across 2^31.
---
 src/emc/motion/axis.c                 |  2 +-
 tests/motion/jogwheel-axis/test-ui.py | 21 +++++++++++++++++++++
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/src/emc/motion/axis.c b/src/emc/motion/axis.c
index f6dd8d4aef0..4aa4a26ba13 100644
--- a/src/emc/motion/axis.c
+++ b/src/emc/motion/axis.c
@@ -447,7 +447,7 @@ void axis_handle_jogwheels(bool motion_teleop_flag, bool motion_enable_flag, boo
             aaccel_limit = ajog_accel_fraction * axis->acc_limit;
         }
 
-        new_ajog_counts = hal_get_si32(axis_data->ajog_counts);
+        new_ajog_counts = hal_get_sint(axis_data->ajog_counts);
         delta = new_ajog_counts - axis->old_ajog_counts;
         axis->old_ajog_counts = new_ajog_counts;
         if ( first_pass ) { continue; }
diff --git a/tests/motion/jogwheel-axis/test-ui.py b/tests/motion/jogwheel-axis/test-ui.py
index 052a8e2a6f8..dc3adba12bb 100755
--- a/tests/motion/jogwheel-axis/test-ui.py
+++ b/tests/motion/jogwheel-axis/test-ui.py
@@ -53,6 +53,23 @@ def jog_axis(axis_letter, counts=1, scale=0.001):
         sys.exit(1)
 
 
+def preset_counts(axis_letter, counts):
+    # with jog-enable off motion takes the new counts without moving
+    h['axis-%c-jog-enable' % axis_letter] = 0
+    h['axis-%c-jog-counts' % axis_letter] = counts
+
+    timeout = 5.0
+    start_time = time.time()
+    s.poll()
+    start_beat = s.heartbeat
+    while s.heartbeat - start_beat < 2:
+        if time.time() - start_time > timeout:
+            print("motion heartbeat did not advance")
+            sys.exit(1)
+        time.sleep(0.010)
+        s.poll()
+
+
 #
 # set up pins
 # shell out to halcmd to make nets to halui and motion
@@ -115,5 +132,9 @@ def jog_axis(axis_letter, counts=1, scale=0.001):
 jog_axis('y', counts=10, scale=-0.025)
 jog_axis('z', counts=-100, scale=0.100)
 
+# counts crossing 2^31 jog by the count difference
+preset_counts('x', 2**31 - 2)
+jog_axis('x', counts=4, scale=0.001)
+
 sys.exit(0)