From 73a483c2657d97619021b85759bc742f637cfff4 Mon Sep 17 00:00:00 2001
From: Lorenz Meier <lm@inf.ethz.ch>
Date: Fri, 24 Jan 2014 17:30:40 +0100
Subject: [PATCH] Finally fix the timing race between the IO driver, IO
 uploader and the on-IO firmware by making the uploader tolerant of timing
 offsets.

---
 src/drivers/px4io/px4io_uploader.cpp | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/src/drivers/px4io/px4io_uploader.cpp b/src/drivers/px4io/px4io_uploader.cpp
index d9f991210d..dd8abbac5a 100644
--- a/src/drivers/px4io/px4io_uploader.cpp
+++ b/src/drivers/px4io/px4io_uploader.cpp
@@ -121,8 +121,15 @@ PX4IO_Uploader::upload(const char *filenames[])
 	cfsetspeed(&t, 115200);
 	tcsetattr(_io_fd, TCSANOW, &t);
 
-	/* look for the bootloader */
-	ret = sync();
+	/* look for the bootloader for 150 ms */
+	for (int i = 0; i < 15; i++) {
+		ret = sync();
+		if (ret == OK) {
+			break;
+		} else {
+			usleep(10000);
+		}
+	}
 
 	if (ret != OK) {
 		/* this is immediately fatal */