From cec9f090c49ff844bcdad669ad730cabdc33257b Mon Sep 17 00:00:00 2001
From: firestar5683 <168790843+firestar5683@users.noreply.github.com>
Date: Wed, 24 Jun 2026 22:51:14 -0500
Subject: [PATCH] Bolt Pedal Friction Tune

---
 selfdrive/controls/lib/longcontrol.py        | 10 ++++----
 selfdrive/controls/tests/test_longcontrol.py | 24 ++++++++++++++++----
 2 files changed, 24 insertions(+), 10 deletions(-)

diff --git a/selfdrive/controls/lib/longcontrol.py b/selfdrive/controls/lib/longcontrol.py
index 4cee83a3c..54267e8fd 100644
--- a/selfdrive/controls/lib/longcontrol.py
+++ b/selfdrive/controls/lib/longcontrol.py
@@ -332,12 +332,10 @@ class LongControl:
     if a_target >= pedal_regen_limit:
       return feedforward
 
-    # Preserve the existing pedal/interceptor shaping up to the known regen
-    # envelope, then restore full-gain feedforward only for the extra decel
-    # that must be satisfied by friction blending.
-    pedal_component = pedal_regen_limit * self.feedforward_gain
-    friction_component = a_target - pedal_regen_limit
-    return pedal_component + friction_component
+    friction_gap = pedal_regen_limit - a_target
+    gain_restore = float(interp(friction_gap, [0.0, 0.25, 0.75], [0.0, 0.6, 1.0]))
+    effective_gain = self.feedforward_gain + ((1.0 - self.feedforward_gain) * gain_restore)
+    return a_target * effective_gain
 
   def update(self, active, CS, a_target, should_stop, accel_limits, starpilot_toggles):
     """Update longitudinal control. This updates the state machine and runs a PID loop"""
diff --git a/selfdrive/controls/tests/test_longcontrol.py b/selfdrive/controls/tests/test_longcontrol.py
index 356f7be77..30fdc7a5e 100644
--- a/selfdrive/controls/tests/test_longcontrol.py
+++ b/selfdrive/controls/tests/test_longcontrol.py
@@ -493,11 +493,27 @@ def test_bolt_acc_pedal_friction_feedforward_restores_full_gain_beyond_regen_env
   CP.longitudinalTuning.kfDEPRECATED = 0.20
 
   lc = LongControl(CP)
-  pedal_regen_limit = float(longcontrol.interp(4.73, longcontrol.BOLT_ACC_PEDAL_REGEN_LIMIT_BP,
-                                               longcontrol.BOLT_ACC_PEDAL_REGEN_LIMIT_V))
-  expected = pedal_regen_limit * 0.20 + (-3.22 - pedal_regen_limit)
 
-  assert lc._get_longitudinal_feedforward(-3.22, 4.73) == pytest.approx(expected)
+  assert lc._get_longitudinal_feedforward(-3.22, 4.73) == pytest.approx(-3.22)
+
+
+def test_bolt_acc_pedal_friction_feedforward_blends_back_in_for_small_friction_request():
+  CP = make_longcontrol_cp(
+    brand="gm",
+    enableGasInterceptorDEPRECATED=True,
+    flags=GMFlags.PEDAL_LONG.value,
+    carFingerprint=CAR.CHEVROLET_BOLT_ACC_2022_2023_PEDAL,
+  )
+  CP.longitudinalTuning.kfDEPRECATED = 0.20
+
+  lc = LongControl(CP)
+  pedal_regen_limit = float(longcontrol.interp(20.0, longcontrol.BOLT_ACC_PEDAL_REGEN_LIMIT_BP,
+                                               longcontrol.BOLT_ACC_PEDAL_REGEN_LIMIT_V))
+  a_target = pedal_regen_limit - 0.10
+  gain_restore = float(longcontrol.interp(0.10, [0.0, 0.25, 0.75], [0.0, 0.6, 1.0]))
+  expected = a_target * (0.20 + ((1.0 - 0.20) * gain_restore))
+
+  assert lc._get_longitudinal_feedforward(a_target, 20.0) == pytest.approx(expected)
 
 
 def test_bolt_cc_pedal_friction_feedforward_remains_fully_scaled_by_kf():