[PATCH v2 2/3] tools: kwboot: Check if baudrate value is supported before sending image

["Pali Rohár" <pali@kernel.org>]

Call kwboot_open_tty() which baudrate value which was specified at the
command line by option -B. This function returns error if baudrate is not
supported by selected tty device.

Initial baudrate for image transfer is always 115200, so call
kwboot_tty_change_baudrate() with value 115200 immediately after
kwboot_open_tty() if baudrate specified by option -B is different than
115200.

This makes kwboot fail immediately, informing that baudrate is unsupported,
instead of failing only after the first part of image is already sent.

Signed-off-by: Pali Rohár <pali@kernel.org>
---
 tools/kwboot.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/tools/kwboot.c b/tools/kwboot.c
index 986f27c2012a..3b45e19a30aa 100644
--- a/tools/kwboot.c
+++ b/tools/kwboot.c
@@ -2139,12 +2139,24 @@ main(int argc, char **argv)
 		goto usage;
 	}
 
-	tty = kwboot_open_tty(ttypath, imgpath ? 115200 : baudrate);
+	tty = kwboot_open_tty(ttypath, baudrate);
 	if (tty < 0) {
 		perror(ttypath);
 		goto out;
 	}
 
+	/*
+	 * initial baudrate for image transfer is always 115200,
+	 * the change to different baudrate is done only after the header is sent
+	 */
+	if (imgpath && baudrate != 115200) {
+		rc = kwboot_tty_change_baudrate(tty, 115200);
+		if (rc) {
+			perror(ttypath);
+			goto out;
+		}
+	}
+
 	if (baudrate == 115200)
 		/* do not change baudrate during Xmodem to the same value */
 		baudrate = 0;
-- 
2.20.1