Reset baudrate when connecting from Python (commaai#1837)

* Reset baudrate when connecting from Python

* unused

Author: pd0wm

python/__init__.py

@@ -28,6 +28,7 @@
 CANPACKET_HEAD_SIZE = 0x6
 DLC_TO_LEN = [0, 1, 2, 3, 4, 5, 6, 7, 8, 12, 16, 20, 24, 32, 48, 64]
 LEN_TO_DLC = {length: dlc for (dlc, length) in enumerate(DLC_TO_LEN)}
+PANDA_BUS_CNT = 4
 
 
 def calculate_checksum(data):
@@ -234,20 +235,18 @@ class Panda:
   FLAG_FORD_LONG_CONTROL = 1
   FLAG_FORD_CANFD = 2
 
-  def __init__(self, serial: Optional[str] = None, claim: bool = True, disable_checks: bool = True):
+  def __init__(self, serial: Optional[str] = None, claim: bool = True, disable_checks: bool = True, can_speed_kbps: int = 500):
     self._connect_serial = serial
     self._disable_checks = disable_checks
 
     self._handle: BaseHandle
     self._handle_open = False
     self.can_rx_overflow_buffer = b''
+    self._can_speed_kbps = can_speed_kbps
 
     # connect and set mcu type
     self.connect(claim)
 
-    # reset comms
-    self.can_reset_communications()
-
   def __enter__(self):
     return self
 
@@ -305,6 +304,13 @@ def connect(self, claim=True, wait=False):
       self.set_heartbeat_disabled()
       self.set_power_save(0)
 
+    # reset comms
+    self.can_reset_communications()
+
+    # set CAN speed
+    for bus in range(PANDA_BUS_CNT):
+      self.set_can_speed_kbps(bus, self._can_speed_kbps)
+
   @classmethod
   def spi_connect(cls, serial, ignore_version=False):
     # get UID to confirm slave is present and up