tmc: Retry register init during connect

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

klippy/extras/tmc.py

@@ -101,10 +101,18 @@ class TMCCommandHelper:
         for reg_name, val in self.fields.registers.items():
             self.mcu_tmc.set_register(reg_name, val, print_time)
     def _handle_connect(self):
+        retry_count = 0
+        while 1:
             try:
                 self._init_registers(0.)
+                return
             except self.printer.command_error as e:
+                logging.exception("TMC init error")
+                retry_count += 1
+                if retry_count > 5:
                     raise self.printer.config_error(str(e))
+                reactor = self.printer.get_reactor()
+                reactor.pause(reactor.monotonic() + 1.)
     cmd_INIT_TMC_help = "Initialize TMC stepper driver registers"
     def cmd_INIT_TMC(self, params):
         logging.info("INIT_TMC %s", self.name)