tools: kwboot: Fix kwboot_xm_sendblock() function when kwboot_tty_recv() fails

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>
Reviewed-by: Stefan Roese <sr@denx.de>

diff --git a/tools/kwboot.c b/tools/kwboot.c
index 454339d..b9a402c 100644 (file)
--- 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);