[PATCH 1/3] tty: fix termios input-speed encoding

From: Johan Hovold <johan@kernel.org>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>,
	Alan Cox <gnomes@lxorguk.ukuu.org.uk>,
	linux-kernel@vger.kernel.org, Johan Hovold <johan@kernel.org>
Subject: [PATCH 1/3] tty: fix termios input-speed encoding
Date: Sun, 15 Jul 2018 15:39:33 +0200	[thread overview]
Message-ID: <20180715133935.24964-2-johan@kernel.org> (raw)
In-Reply-To: <20180715133935.24964-1-johan@kernel.org>

Make sure to clear the CIBAUD bits before OR-ing the new mask when
encoding the termios input baud rate.

This could otherwise lead to an incorrect input rate being reported back
and incidentally set on subsequent termios updates.

Fixes: edc6afc54968 ("[PATCH] tty: switch to ktermios and new framework")
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/tty/tty_baudrate.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/tty/tty_baudrate.c b/drivers/tty/tty_baudrate.c
index 6ff8cdfc9d2a..a7a438f54e69 100644
--- a/drivers/tty/tty_baudrate.c
+++ b/drivers/tty/tty_baudrate.c
@@ -169,6 +169,9 @@ void tty_termios_encode_baud_rate(struct ktermios *termios,
 		ibinput = 1;	/* An input speed was specified */
 #endif
 	termios->c_cflag &= ~CBAUD;
+#ifdef IBSHIFT
+	termios->c_cflag &= ~(CBAUD << IBSHIFT);
+#endif
 
 	/*
 	 *	Our goal is to find a close match to the standard baud rate
-- 
2.18.0

