Merge pull request #12805 from fkjagodzinski/test_update-usb_serial-minimal_printf

Tests: USBSerial: Handle minimal printf limitations

Author: 0xc0170

TESTS/host_tests/usb_device_serial.py

@@ -47,8 +47,8 @@
 # during terminal reopen test.
 TERM_REOPEN_DELAY = 0.1
 
-# 6 (baud) + 2 (bits) + 1 (parity) + 1 (stop) + 3 * comma
-LINE_CODING_STRLEN = 13
+LINE_CODING_SEP = ','
+LINE_CODING_DELIM = ';'
 
 
 def usb_serial_name(serial_number):
@@ -269,16 +269,17 @@ def change_line_coding(self):
         mbed_serial.reset_output_buffer()
         mbed_serial.dtr = True
         try:
-            payload = six.ensure_str(mbed_serial.read(LINE_CODING_STRLEN))
-            while len(payload) == LINE_CODING_STRLEN:
-                baud, bits, parity, stop = (int(i) for i in payload.split(','))
+            payload = six.ensure_str(mbed_serial.read_until(LINE_CODING_DELIM))
+            while len(payload) > 0:
+                baud, bits, parity, stop = (
+                    int(i) for i in payload.strip(LINE_CODING_DELIM).split(LINE_CODING_SEP))
                 new_line_coding = {
                     'baudrate': baud,
                     'bytesize': self._BYTESIZES[bits],
                     'parity': self._PARITIES[parity],
                     'stopbits': self._STOPBITS[stop]}
                 mbed_serial.apply_settings(new_line_coding)
-                payload = six.ensure_str(mbed_serial.read(LINE_CODING_STRLEN))
+                payload = six.ensure_str(mbed_serial.read_until(LINE_CODING_DELIM))
         except serial.SerialException as exc:
             self.log('TEST ERROR: {}'.format(exc))
             self.notify_complete(False)

TESTS/usb_device/serial/main.cpp

@@ -84,7 +84,8 @@
 #define SERIAL_LOOPBACK_REPS 100
 #define USB_RECONNECT_DELAY_MS 1
 
-#define LINE_CODING_STRLEN 13 // 6 + 2 + 1 + 1 + 3 * comma
+#define LINE_CODING_SEP (',')
+#define LINE_CODING_DELIM (';')
 
 #define USB_DEV_SN_LEN (32) // 32 hex digit UUID
 #define NONASCII_CHAR ('?')
@@ -776,9 +777,9 @@ void test_serial_line_coding_change()
     for (size_t i = 0; i < num_line_codings; i++) {
         lc_expected = &(test_codings[i]);
         num_expected_callbacks = lc_prev->get_num_diffs(*lc_expected);
-        rc = usb_serial.printf("%06i,%02i,%01i,%01i", lc_expected->baud, lc_expected->bits, lc_expected->parity,
-                               lc_expected->stop);
-        TEST_ASSERT_EQUAL_INT(LINE_CODING_STRLEN, rc);
+        rc = usb_serial.printf("%06i,%02i,%01i,%01i%c", lc_expected->baud, lc_expected->bits, lc_expected->parity,
+                               lc_expected->stop, LINE_CODING_DELIM);
+        TEST_ASSERT(rc > 0);
         // The pyserial Python module does not update all line coding params
         // at once. It updates params one by one instead, and since every
         // update is followed by port reconfiguration we get multiple