Merge pull request #301 from riscv/mpsse_flush

Add wall clock timeout to mpsse_flush()

src/jtag/drivers/mpsse.c

@@ -22,6 +22,7 @@
 
 #include "mpsse.h"
 #include "helper/log.h"
+#include "helper/time_support.h"
 #include <libusb.h>
 
 /* Compatibility define for older libusb-1.0 */
@@ -892,6 +893,7 @@ int mpsse_flush(struct mpsse_ctx *ctx)
 	}
 
 	/* Polling loop, more or less taken from libftdi */
+	int64_t start = timeval_ms();
 	while (!write_result.done || !read_result.done) {
 		struct timeval timeout_usb;
 
@@ -914,6 +916,11 @@ int mpsse_flush(struct mpsse_ctx *ctx)
 					break;
 			}
 		}
+
+		if (timeval_ms() - start > 2000) {
+			LOG_ERROR("Timed out handling USB events in mpsse_flush().");
+			break;
+		}
 	}
 
 error_check: