[PATCH 2/7] scripts: kwboot: flush input and output only once

[Uwe Kleine-König]

When flushing input before sending of a boot message the acknowledging
reply for the previous message from the CPU might be discarded and so
missed.

So only flush once before sending boot messages in a loop.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig at pengutronix.de>
---
 scripts/kwboot.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/scripts/kwboot.c b/scripts/kwboot.c
index 9d680dc576a7..9dfaf4a8dfb0 100644
--- a/scripts/kwboot.c
+++ b/scripts/kwboot.c
@@ -273,11 +273,11 @@ kwboot_bootmsg(int tty, void *msg)
 	else
 		kwboot_printv("Sending boot message. Please reboot the target...");
 
-	do {
-		rc = tcflush(tty, TCIOFLUSH);
-		if (rc)
-			break;
+	rc = tcflush(tty, TCIOFLUSH);
+	if (rc)
+		return rc;
 
+	do {
 		rc = kwboot_tty_send(tty, msg, 8);
 		if (rc) {
 			usleep(KWBOOT_MSG_REQ_DELAY * 1000);
@@ -302,13 +302,13 @@ kwboot_debugmsg(int tty, void *msg)
 
 	kwboot_printv("Sending debug message. Please reboot the target...");
 
+	rc = tcflush(tty, TCIOFLUSH);
+	if (rc)
+		return rc;
+
 	do {
 		char buf[16];
 
-		rc = tcflush(tty, TCIOFLUSH);
-		if (rc)
-			break;
-
 		rc = kwboot_tty_send(tty, msg, 8);
 		if (rc) {
 			usleep(KWBOOT_MSG_REQ_DELAY * 1000);
-- 
2.9.3