Generate media key in platform sepcific way and fix cable issues

sonic_platform_base/sfp_base.py

@@ -467,3 +467,22 @@ def get_xcvr_api(self):
         if self._xcvr_api is None:
             self.refresh_xcvr_api()
         return self._xcvr_api
+
+    def get_platform_media_key(self, transceiver_dict, port_speed, lane_count):
+        """
+        Retrieves the media key constructed in a platform specific way,
+        to be used for parsing the media settings
+
+        Args:
+             transceiver_dict :
+                     SFP transceived EEPROM dictionary
+             port_speed:
+                     Configured port speed
+             lane_count:
+                     Number of lanes assigned for that port
+
+        Returns:
+            a dictionary with string values defined for keys,
+            {'vendor_key':'', 'media_key':'', 'lane_speed_key':'')
+        """
+        raise NotImplementedError

sonic_platform_base/sonic_xcvr/api/public/sff8436.py

@@ -45,6 +45,7 @@ def get_transceiver_info(self):
             if len > 0:
                 cable_len = len
                 cable_type = type
+                break
 
         xcvr_info = {
             "type": serial_id[consts.ID_FIELD],

sonic_platform_base/sonic_xcvr/api/public/sff8636.py

@@ -52,6 +52,7 @@ def get_transceiver_info(self):
             if len > 0:
                 cable_len = len
                 cable_type = type
+                break
 
         xcvr_info = {
             "type": serial_id[consts.ID_FIELD],

sonic_platform_base/sonic_xcvr/xcvr_api_factory.py

@@ -61,14 +61,14 @@ def _get_vendor_name(self):
        name_data = self.reader(VENDOR_NAME_OFFSET, VENDOR_NAME_LENGTH)
        if name_data is None:
            return None
-       vendor_name = name_data.decode()
+       vendor_name = name_data.decode("ascii", errors="ignore")
        return vendor_name.strip()
 
     def _get_vendor_part_num(self):
        part_num = self.reader(VENDOR_PART_NUM_OFFSET, VENDOR_PART_NUM_LENGTH)
        if part_num is None:
            return None
-       vendor_pn = part_num.decode()
+       vendor_pn = part_num.decode("ascii", errors="ignore")
        return vendor_pn.strip()
 
     def create_xcvr_api(self):