manually did arduino#88 and tested - fixes keyboardcontroller sluggishness

Author: ladyada

libraries/USBHost/src/Usb.cpp

@@ -262,7 +262,8 @@ uint32_t USBHost::InTransfer(EpInfo *pep, uint32_t nak_limit, uint8_t *nbytesptr
             continue;
 		}
         if(rcode) {
-                //printf(">>>>>>>> Problem! dispatchPkt %2.2x\r\n", rcode);
+                uhd_freeze_pipe(pep->epAddr);
+								//printf(">>>>>>>> Problem! dispatchPkt %2.2x\r\n", rcode);
                 return(rcode);// break; //should be 0, indicating ACK. Else return error code.
         }
         /* check for RCVDAVIRQ and generate error if not present */
@@ -304,6 +305,7 @@ uint32_t USBHost::InTransfer(EpInfo *pep, uint32_t nak_limit, uint8_t *nbytesptr
             break;
 		} // if
 	} //while( 1 )
+	uhd_freeze_pipe(pep->epAddr);
 	return ( rcode);
 }
 
@@ -422,6 +424,15 @@ uint32_t USBHost::dispatchPkt(uint32_t token, uint32_t epAddr, uint32_t nak_limi
 		}
 
 		//case hrNAK:
+		if((USB->HOST.HostPipe[epAddr].PINTFLAG.reg & USB_HOST_PINTFLAG_TRFAIL) ) {
+	 			USB->HOST.HostPipe[epAddr].PINTFLAG.reg = USB_HOST_PINTFLAG_TRFAIL;
+	 			nak_count++;
+	 			if(nak_limit && (nak_count == nak_limit)) {
+	 				rcode = USB_ERRORFLOW;
+	 				return (rcode);
+	 			}
+	  }
+
 		if( (usb_pipe_table[epAddr].HostDescBank[0].STATUS_BK.reg & USB_ERRORFLOW ) ) {
 			nak_count++;
 			if(nak_limit && (nak_count == nak_limit)) {