[PATCH u-boot-marvell v3 06/39] tools: kwboot: Fix kwboot_xm_sendblock() function when kwboot_tty_recv() fails

["Marek Behún" <kabel@kernel.org>]

From: Pali Rohár <pali@kernel.org>

When kwboot_tty_recv() fails or times out, it does not set the `c`
variable to NAK. The variable is then compared, while it holds either
an undefined value or a value from previous iteration. Set `c` to NAK so
that the other side will try to resend current block, and remove the
now unnecessary break.

In other failure cases return immediately.

Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
---
 tools/kwboot.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/tools/kwboot.c b/tools/kwboot.c
index 454339db14..b9a402ca91 100644
--- a/tools/kwboot.c
+++ b/tools/kwboot.c
@@ -380,12 +380,15 @@ kwboot_xm_sendblock(int fd, struct kwboot_block *block)
 	do {
 		rc = kwboot_tty_send(fd, block, sizeof(*block));
 		if (rc)
-			break;
+			return rc;
 
 		do {
 			rc = kwboot_tty_recv(fd, &c, 1, blk_rsp_timeo);
-			if (rc)
-				break;
+			if (rc) {
+				if (errno != ETIMEDOUT)
+					return rc;
+				c = NAK;
+			}
 
 			if (c != ACK && c != NAK && c != CAN)
 				printf("%c", c);
-- 
2.32.0