Make USB disconnect + connect time explicit

Create the define MIN_DISCONNECT_TIME_US to be used as the amount of
time that must pass between connect and disconnect for the host to
reliably detect reconnection. Replace the wait calls delaying for this
value to wait_us to indicate the precision required. Finally, remove
the unnecessary calls to wait_ms in
repeated_construction_destruction_test.

Author: c1728p9

TESTS/usb_device/basic/main.cpp

@@ -23,6 +23,12 @@
 
 #include "USBTester.h"
 
+// If disconnect() + connect() occur too fast the reset event will be dropped.
+// At a minimum there should be a 200us delay between disconnect and connect.
+// To be on the safe side I would recommend a 1ms delay, so the host controller
+// has an entire USB frame to detect the disconnect.
+#define MIN_DISCONNECT_TIME_US  1000
+
 #if !defined(DEVICE_USBDEVICE) || !DEVICE_USBDEVICE
 #error [NOT_SUPPORTED] USB Device not supported for this target
 #endif
@@ -166,11 +172,7 @@ void device_soft_reconnection_test()
 
         for(int i = 0; i < reconnect_try_count; i++) {
             serial.disconnect();
-            // If disconnect() + connect() occur too fast the reset event will be dropped.
-            // At a minimum there should be a 200us delay between disconnect and connect.
-            // To be on the safe side I would recommend a 1ms delay, so the host controller
-            // has an entire USB frame to detect the disconnect.
-            wait_ms(1);
+            wait_us(MIN_DISCONNECT_TIME_US);
             serial.connect();
             greentea_send_kv("device_soft_reconnection_test", serial.get_serial_desc_string());
             // Wait for host before terminating
@@ -179,13 +181,13 @@ void device_soft_reconnection_test()
         }
 
         serial.disconnect();
-        wait_ms(1);
+        wait_us(MIN_DISCONNECT_TIME_US);
         serial.connect();
         serial.disconnect();
-        wait_ms(1);
+        wait_us(MIN_DISCONNECT_TIME_US);
         serial.connect();
         serial.disconnect();
-        wait_ms(1);
+        wait_us(MIN_DISCONNECT_TIME_US);
         serial.connect();
         greentea_send_kv("device_soft_reconnection_test", serial.get_serial_desc_string());
         // Wait for host before terminating
@@ -228,50 +230,44 @@ void repeated_construction_destruction_test()
     {
         USBTester serial(vendor_id, product_id, product_release, true);
         TEST_ASSERT_EQUAL(true, serial.configured());
-        wait_ms(1);
     }
 
-    wait_ms(1);
+    wait_us(MIN_DISCONNECT_TIME_US);
     {
         USBTester serial(vendor_id, product_id, product_release, true);
         TEST_ASSERT_EQUAL(true, serial.configured());
-        wait_ms(1);
     }
 
-    wait_ms(1);
+    wait_us(MIN_DISCONNECT_TIME_US);
     {
         USBTester serial(vendor_id, product_id, product_release, true);
         TEST_ASSERT_EQUAL(true, serial.configured());
-        wait_ms(1);
     }
 
-    wait_ms(1);
+    wait_us(MIN_DISCONNECT_TIME_US);
     {
         USBTester serial(vendor_id, product_id, product_release, true);
         TEST_ASSERT_EQUAL(true, serial.configured());
-        wait_ms(1);
         greentea_send_kv("repeated_construction_destruction_test", serial.get_serial_desc_string());
         // Wait for host before terminating
         greentea_parse_kv(_key, _value, sizeof(_key), sizeof(_value));
         TEST_ASSERT_EQUAL_STRING("pass", _key);
     }
 
-    wait_ms(1);
+    wait_us(MIN_DISCONNECT_TIME_US);
     {
         USBTester serial(vendor_id, product_id, product_release, true);
         TEST_ASSERT_EQUAL(true, serial.configured());
-        wait_ms(1);
         greentea_send_kv("repeated_construction_destruction_test", serial.get_serial_desc_string());
         // Wait for host before terminating
         greentea_parse_kv(_key, _value, sizeof(_key), sizeof(_value));
         TEST_ASSERT_EQUAL_STRING("pass", _key);
     }
 
-    wait_ms(1);
+    wait_us(MIN_DISCONNECT_TIME_US);
     {
         USBTester serial(vendor_id, product_id, product_release, true);
         TEST_ASSERT_EQUAL(true, serial.configured());
-        wait_ms(1);
         greentea_send_kv("repeated_construction_destruction_test", serial.get_serial_desc_string());
         // Wait for host before terminating
         greentea_parse_kv(_key, _value, sizeof(_key), sizeof(_value));