Tiny Dancer 2

opendbc_repo/opendbc/car/gm/carcontroller.py

@@ -690,7 +690,8 @@ class CarController(CarControllerBase):
             hold_standstill = CS.pcm_acc_status == AccState.STANDSTILL
             hold_near_stop = CS.out.vEgo < self.params.NEAR_STOP_BRAKE_PHASE
             can_sends.append(gmcan.create_friction_brake_command(
-              self.packer_ch, friction_brake_bus, hold_brake, idx, False, hold_near_stop, hold_standstill, self.CP))
+              self.packer_ch, friction_brake_bus, hold_brake, idx, False, hold_near_stop, hold_standstill,
+              self.CP, allow_near_stop_mode=True))
             CS.auto_hold_engaged = True
             CS.auto_hold_fault_suppression_timer = 1.0
           else:
@@ -765,7 +766,8 @@ class CarController(CarControllerBase):
         hold_standstill = CS.pcm_acc_status == AccState.STANDSTILL
         hold_near_stop = CS.out.vEgo < self.params.NEAR_STOP_BRAKE_PHASE
         can_sends.append(gmcan.create_friction_brake_command(
-          self.packer_ch, get_friction_brake_bus(self.CP), hold_brake, idx, False, hold_near_stop, hold_standstill, self.CP))
+          self.packer_ch, get_friction_brake_bus(self.CP), hold_brake, idx, False, hold_near_stop, hold_standstill,
+          self.CP, allow_near_stop_mode=True))
         CS.auto_hold_engaged = True
         CS.auto_hold_fault_suppression_timer = 1.0
       elif self.frame % 4 == 0:

opendbc_repo/opendbc/car/gm/gmcan.py

@@ -179,7 +179,7 @@ def create_ecm_cruise_control_command(packer, bus, enabled, target_speed_kph):
   return CanData(0x3D1, bytes(dat), bus)
 
 
-def create_friction_brake_command(packer, bus, apply_brake, idx, enabled, near_stop, at_full_stop, CP):
+def get_friction_brake_mode(apply_brake, enabled, near_stop, at_full_stop, CP, allow_near_stop_mode=False):
   mode = 0x1
 
   # TODO: Understand this better. Volts and ICE Camera ACC cars are 0x1 when enabled with no brake
@@ -190,11 +190,17 @@ def create_friction_brake_command(packer, bus, apply_brake, idx, enabled, near_s
     mode = 0xa
     if at_full_stop:
       mode = 0xd
+    elif allow_near_stop_mode and near_stop:
+      # Stock Volt auto hold can run with cruise main on but ACC inactive, so
+      # there is no stock STANDSTILL state to promote 0xa -> 0xd. Restore the
+      # older near-stop hold mode only for that path.
+      mode = 0xb
 
-    # TODO: this is to have GM bringing the car to complete stop,
-    # but currently it conflicts with OP controls, so turned off. Not set by all cars
-    #elif near_stop:
-    #  mode = 0xb
+  return mode
+
+
+def create_friction_brake_command(packer, bus, apply_brake, idx, enabled, near_stop, at_full_stop, CP, allow_near_stop_mode=False):
+  mode = get_friction_brake_mode(apply_brake, enabled, near_stop, at_full_stop, CP, allow_near_stop_mode)
 
   brake = (0x1000 - apply_brake) & 0xfff
   checksum = (0x10000 - (mode << 12) - brake - idx) & 0xffff

opendbc_repo/opendbc/car/gm/tests/test_carcontroller.py

@@ -46,6 +46,7 @@ from opendbc.car.gm.carcontroller import (
   supports_volt_auto_hold,
   use_interceptor_sng_launch,
 )
+from opendbc.car.gm.gmcan import get_friction_brake_mode
 from opendbc.car.gm.values import AccState, CAR, GMFlags
 from opendbc.car.structs import CarParams
 
@@ -280,6 +281,19 @@ def test_auto_hold_activation_allows_standstill_even_if_speed_filter_is_slightly
   )
 
 
+def test_friction_brake_mode_keeps_near_stop_disabled_for_regular_long_braking():
+  CP = SimpleNamespace(carFingerprint=CAR.CHEVROLET_VOLT_ASCM)
+
+  assert get_friction_brake_mode(120, False, True, False, CP) == 0xa
+
+
+def test_friction_brake_mode_uses_near_stop_hold_mode_for_volt_auto_hold():
+  CP = SimpleNamespace(carFingerprint=CAR.CHEVROLET_VOLT_ASCM)
+
+  assert get_friction_brake_mode(120, False, True, False, CP, allow_near_stop_mode=True) == 0xb
+  assert get_friction_brake_mode(120, False, True, True, CP, allow_near_stop_mode=True) == 0xd
+
+
 def test_calc_pedal_command_small_accel_deadband_keeps_creep_target_stable():
   pos_controller = _controller()
   neg_controller = _controller()