Update USBCore.cpp

Author: Flamethr0wer

cores/arduino/USBCore.cpp

@@ -845,23 +845,17 @@ ISR(USB_GEN_vect)
 	// Therefore the we enable it only when USB is suspended
 	if (udint & (1<<WAKEUPI))
 	{
-		UDIEN = (UDIEN & ~(1<<WAKEUPE)) | (1<<SUSPE); // Disable interrupts for WAKEUP and enable interrupts for SUSPEND
-
-		//TODO
-		// WAKEUPI shall be cleared by software (USB clock inputs must be enabled before).
-		//USB_ClockEnable();
-		UDINT &= ~(1<<WAKEUPI);
-		_usbSuspendState = (_usbSuspendState & ~(1<<SUSPI)) | (1<<WAKEUPI);
+		USB_ClockEnable();             // restart PLL, unfreeze clock
+  		UDIEN = (UDIEN & ~(1<<WAKEUPE)) | (1<<SUSPE);
+  		UDINT &= ~(1<<WAKEUPI);
+  		_usbSuspendState &= ~(1<<SUSPI);
 	}
 	else if (udint & (1<<SUSPI)) // only one of the WAKEUPI / SUSPI bits can be active at time
 	{
-		UDIEN = (UDIEN & ~(1<<SUSPE)) | (1<<WAKEUPE); // Disable interrupts for SUSPEND and enable interrupts for WAKEUP
-
-		//TODO
-		//USB_ClockDisable();
-
-		UDINT &= ~((1<<WAKEUPI) | (1<<SUSPI)); // clear any already pending WAKEUP IRQs and the SUSPI request
-		_usbSuspendState = (_usbSuspendState & ~(1<<WAKEUPI)) | (1<<SUSPI);
+		USB_ClockDisable();        // stop PLL, freeze USB clock
+  		UDIEN = (UDIEN & ~(1<<SUSPE)) | (1<<WAKEUPE);
+  		UDINT &= ~((1<<WAKEUPI)|(1<<SUSPI));
+  		_usbSuspendState |= (1<<SUSPI);
 	}
 }