waveform: fixes

artiq/dashboard/waveform.py

@@ -516,6 +516,7 @@ class WaveformArea(QtWidgets.QWidget):
             cw.update_x_max()
         maximum = self._state["stopped_x"]
         self._ref_axis.setLimits(xMax=maximum)
+        if maximum is not None:
             self._ref_axis.setRange(xRange=(0, maximum))
 
     def on_cursor_move(self, x):
@@ -680,7 +681,7 @@ class WaveformDock(QtWidgets.QDockWidget):
             "data": dict(),
         }
 
-        self._current_dir = "c://"
+        self._current_dir = os.getcwd()
 
         self.proxy_client = WaveformProxyClient(self._state, loop)
         devices_sub = Subscriber("devices", self.init_ddb, self.update_ddb)
@@ -756,22 +757,9 @@ class WaveformDock(QtWidgets.QDockWidget):
         ddb = self._ddb
         trace = comm_analyzer.decoded_dump_to_waveform_data(ddb, decoded_dump)
         self._state.update(trace)
-        self._dump = args
+        self._dump = data
         self.traceDataChanged.emit()
 
-    def _decode_dump(self):
-        dump = self._dump
-        header = comm_analyzer.decode_header_from_receiver(*dump)
-        return comm_analyzer.decode_dump_loop(*header)
-
-    def _dump_header(self, endian, payload_length):
-        payload_length_word = struct.pack(endian + "I", payload_length)
-        if endian == ">":
-            endian_byte = b"E"
-        else:
-            endian_byte = b"e"
-        return endian_byte + payload_length_word
-
     async def load_trace(self):
         try:
             filename = await get_open_file_name(
@@ -802,8 +790,7 @@ class WaveformDock(QtWidgets.QDockWidget):
         self._current_dir = os.path.dirname(filename)
         try:
             with open(filename, 'wb') as f:
-                f.write(self._dump_header(dump[0], dump[1]))
-                f.write(dump[2])
+                f.write(self._dump)
 
         except Exception as e:
             logger.error("Failed to save analyzer trace: %s", e)