1 files changed, 13 insertions, 54 deletions

diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index aba74f817dc6..1cec03799cdf 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -1244,42 +1244,13 @@ static __u32 get_ftdi_divisor(struct tty_struct *tty,
 	int div_okay = 1;
 	int baud;
 
-	/*
-	 * The logic involved in setting the baudrate can be cleanly split into
-	 * 3 steps.
-	 * 1. Standard baud rates are set in tty->termios->c_cflag
-	 * 2. If these are not enough, you can set any speed using alt_speed as
-	 * follows:
-	 *    - set tty->termios->c_cflag speed to B38400
-	 *    - set your real speed in tty->alt_speed; it gets ignored when
-	 *      alt_speed==0, (or)
-	 *    - call TIOCSSERIAL ioctl with (struct serial_struct) set as
-	 *	follows:
-	 *      flags & ASYNC_SPD_MASK == ASYNC_SPD_[HI, VHI, SHI, WARP],
-	 *	this just sets alt_speed to (HI: 57600, VHI: 115200,
-	 *	SHI: 230400, WARP: 460800)
-	 * ** Steps 1, 2 are done courtesy of tty_get_baud_rate
-	 * 3. You can also set baud rate by setting custom divisor as follows
-	 *    - set tty->termios->c_cflag speed to B38400
-	 *    - call TIOCSSERIAL ioctl with (struct serial_struct) set as
-	 *	follows:
-	 *      o flags & ASYNC_SPD_MASK == ASYNC_SPD_CUST
-	 *      o custom_divisor set to baud_base / your_new_baudrate
-	 * ** Step 3 is done courtesy of code borrowed from serial.c
-	 *    I should really spend some time and separate + move this common
-	 *    code to serial.c, it is replicated in nearly every serial driver
-	 *    you see.
-	 */
-
-	/* 1. Get the baud rate from the tty settings, this observes
-	      alt_speed hack */
-
 	baud = tty_get_baud_rate(tty);
 	dev_dbg(dev, "%s - tty_get_baud_rate reports speed %d\n", __func__, baud);
 
-	/* 2. Observe async-compatible custom_divisor hack, update baudrate
-	   if needed */
-
+	/*
+	 * Observe deprecated async-compatible custom_divisor hack, update
+	 * baudrate if needed.
+	 */
 	if (baud == 38400 &&
 	    ((priv->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST) &&
 	     (priv->custom_divisor)) {
@@ -1288,8 +1259,6 @@ static __u32 get_ftdi_divisor(struct tty_struct *tty,
 			__func__, priv->custom_divisor, baud);
 	}
 
-	/* 3. Convert baudrate to device-specific divisor */
-
 	if (!baud)
 		baud = 9600;
 	switch (priv->chip_type) {
@@ -1505,8 +1474,7 @@ static int set_serial_info(struct tty_struct *tty,
 	/* Do error checking and permission checking */
 
 	if (!capable(CAP_SYS_ADMIN)) {
-		if (((new_serial.flags & ~ASYNC_USR_MASK) !=
-		     (priv->flags & ~ASYNC_USR_MASK))) {
+		if ((new_serial.flags ^ priv->flags) & ~ASYNC_USR_MASK) {
 			mutex_unlock(&priv->cfg_lock);
 			return -EPERM;
 		}
@@ -1530,23 +1498,14 @@ static int set_serial_info(struct tty_struct *tty,
 check_and_exit:
 	write_latency_timer(port);
 
-	if ((old_priv.flags & ASYNC_SPD_MASK) !=
-	     (priv->flags & ASYNC_SPD_MASK)) {
-		if ((priv->flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI)
-			tty->alt_speed = 57600;
-		else if ((priv->flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI)
-			tty->alt_speed = 115200;
-		else if ((priv->flags & ASYNC_SPD_MASK) == ASYNC_SPD_SHI)
-			tty->alt_speed = 230400;
-		else if ((priv->flags & ASYNC_SPD_MASK) == ASYNC_SPD_WARP)
-			tty->alt_speed = 460800;
-		else
-			tty->alt_speed = 0;
-	}
-	if (((old_priv.flags & ASYNC_SPD_MASK) !=
-	     (priv->flags & ASYNC_SPD_MASK)) ||
-	    (((priv->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST) &&
-	     (old_priv.custom_divisor != priv->custom_divisor))) {
+	if ((priv->flags ^ old_priv.flags) & ASYNC_SPD_MASK ||
+			((priv->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST &&
+			 priv->custom_divisor != old_priv.custom_divisor)) {
+
+		/* warn about deprecation unless clearing */
+		if (priv->flags & ASYNC_SPD_MASK)
+			dev_warn_ratelimited(&port->dev, "use of SPD flags is deprecated\n");
+
 		change_speed(tty, port);
 		mutex_unlock(&priv->cfg_lock);
 	}