--- ../../../lib/pjrc/usb_serial/usb_serial.c	2011-04-19 05:54:12.000000000 -0400
+++ usb_serial.c	2017-08-07 11:32:47.106357362 -0400
@@ -30,6 +30,7 @@
 // Version 1.6: fix zero length packet bug
 // Version 1.7: fix usb_serial_set_control
 
+#include <string.h>
 #define USB_SERIAL_PRIVATE_INCLUDE
 #include "usb_serial.h"
 
@@ -146,7 +147,7 @@
 // in here should only be done by those who've read chapter 9 of the USB
 // spec and relevant portions of any USB class specifications!
 
-static uint8_t PROGMEM device_descriptor[] = {
+static const uint8_t PROGMEM device_descriptor[] = {
 	18,					// bLength
 	1,					// bDescriptorType
 	0x00, 0x02,				// bcdUSB
@@ -164,7 +165,7 @@
 };
 
 #define CONFIG1_DESC_SIZE (9+9+5+5+4+5+7+9+7+7)
-static uint8_t PROGMEM config1_descriptor[CONFIG1_DESC_SIZE] = {
+static const uint8_t PROGMEM config1_descriptor[CONFIG1_DESC_SIZE] = {
 	// configuration descriptor, USB spec 9.6.3, page 264-266, Table 9-10
 	9, 					// bLength;
 	2,					// bDescriptorType;
@@ -248,22 +249,22 @@
 	uint8_t bDescriptorType;
 	int16_t wString[];
 };
-static struct usb_string_descriptor_struct PROGMEM string0 = {
+static const struct usb_string_descriptor_struct PROGMEM string0 = {
 	4,
 	3,
 	{0x0409}
 };
-static struct usb_string_descriptor_struct PROGMEM string1 = {
+static const struct usb_string_descriptor_struct PROGMEM string1 = {
 	sizeof(STR_MANUFACTURER),
 	3,
 	STR_MANUFACTURER
 };
-static struct usb_string_descriptor_struct PROGMEM string2 = {
+static const struct usb_string_descriptor_struct PROGMEM string2 = {
 	sizeof(STR_PRODUCT),
 	3,
 	STR_PRODUCT
 };
-static struct usb_string_descriptor_struct PROGMEM string3 = {
+static const struct usb_string_descriptor_struct PROGMEM string3 = {
 	sizeof(STR_SERIAL_NUMBER),
 	3,
 	STR_SERIAL_NUMBER
@@ -271,7 +272,7 @@
 
 // This table defines which descriptor data is sent for each specific
 // request from the host (in wValue and wIndex).
-static struct descriptor_list_struct {
+static const struct descriptor_list_struct {
 	uint16_t	wValue;
 	uint16_t	wIndex;
 	const uint8_t	*addr;
@@ -324,7 +325,7 @@
         UDCON = 0;				// enable attach resistor
 	usb_configuration = 0;
 	cdc_line_rtsdtr = 0;
-        UDIEN = (1<<EORSTE)|(1<<SOFE);
+        UDIEN = (1<<EORSTE);
 	sei();
 }
 
@@ -358,6 +359,7 @@
 			UEINTX = 0x6B;
 			goto retry;
 		}	
+		UEIENX = (1<<RXOUTE);
 		SREG = intr_state;
 		return -1;
 	}
@@ -646,7 +648,9 @@
 // communication
 uint32_t usb_serial_get_baud(void)
 {
-	return *(uint32_t *)cdc_line_coding;
+	uint32_t res;
+	memcpy(&res, cdc_line_coding, sizeof(res));
+	return res;
 }
 uint8_t usb_serial_get_stopbits(void)
 {
@@ -772,7 +776,14 @@
 //
 ISR(USB_COM_vect)
 {
-        uint8_t intbits;
+        uint8_t intbits = UEINT;
+        if (intbits & (1<<CDC_RX_ENDPOINT)) {
+                UENUM = CDC_RX_ENDPOINT;
+                UEIENX = 0;
+                extern void sched_wake_tasks(void);
+                sched_wake_tasks();
+                return;
+        }
 	const uint8_t *list;
         const uint8_t *cfg;
 	uint8_t i, n, len, en;
