From 15ffaeed867b14ddace545efcd8c0fc42fd1142b Mon Sep 17 00:00:00 2001
From: c_oflynn <c_oflynn>
Date: Sun, 24 Jan 2010 13:01:58 +0000
Subject: [PATCH] Fix for error where USB host could send NAK, but isn't
 considered in jackdaw, resulting in jackdaw hanging

---
 cpu/avr/dev/usb/rndis/rndis.c | 37 ++++++++++++++++++++++-------------
 cpu/avr/dev/usb/usb_drv.h     |  2 ++
 2 files changed, 25 insertions(+), 14 deletions(-)

diff --git a/cpu/avr/dev/usb/rndis/rndis.c b/cpu/avr/dev/usb/rndis/rndis.c
index ef168caee..77e8c83ec 100644
--- a/cpu/avr/dev/usb/rndis/rndis.c
+++ b/cpu/avr/dev/usb/rndis/rndis.c
@@ -210,23 +210,32 @@ uint8_t send_encapsulated_command(uint16_t wLength)
 
 	uint8_t nb_counter;
 
+    //Clear NAK bit
+    Usb_ack_nak_in();
 
-	while (wLength) {
-		nb_counter = EP_CONTROL_LENGTH;
+    while (wLength) {
+        nb_counter = EP_CONTROL_LENGTH;
 
-		//Wait for data to come in
-		while (!(Is_usb_receive_out()));
-			
-		while(nb_counter && wLength) {			
-			encapsulated_buffer[i] = Usb_read_byte();
-			i++;
-			wLength--;
-			nb_counter--;
-		}
-		
-		Usb_ack_receive_out();
+        //Wait for data to come in or nak
+        while((!Is_usb_receive_out()) & (!Is_usb_receive_nak_in()));
 
-	}
+        //Received OUT
+        if (Is_usb_receive_out()) {
+            while(nb_counter && wLength) {
+                encapsulated_buffer[i] = Usb_read_byte();
+                i++;
+                wLength--;
+                nb_counter--;
+            }
+
+            Usb_ack_receive_out();
+
+            //Received NAK, no more data
+            } else  {
+                Usb_ack_nak_in();
+                break;
+            }
+    }
 
 	Usb_send_control_in();
 
diff --git a/cpu/avr/dev/usb/usb_drv.h b/cpu/avr/dev/usb/usb_drv.h
index 4ab7fcb8b..699367b7d 100644
--- a/cpu/avr/dev/usb/usb_drv.h
+++ b/cpu/avr/dev/usb/usb_drv.h
@@ -530,6 +530,8 @@ typedef enum endpoint_parameter{ep_num, ep_type, ep_direction, ep_size, ep_bank,
 #define Usb_ack_nak_out()                         (UEINTX &= ~(1<<NAKOUTI))
    //! acks receive SETUP
 #define Usb_ack_receive_setup()                   (UEINTX &= ~(1<<RXSTPI))
+//! tests if NAK IN received
+#define Is_usb_receive_nak_in()                   (UEINTX &(1<<NAKINI))
    //! acks reveive OUT
 #define Usb_ack_receive_out()                     (UEINTX &= ~(1<<RXOUTI), Usb_ack_fifocon())
    //! acks STALL sent