USB: serial: return errors from break handling

Start propagating errors to user space when setting the break state
fails.

This will be used by follow-on changes to also report when a driver or
device does not support break control.

Tested-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Johan Hovold <johan@kernel.org>

Author: jhovold

drivers/usb/serial/ark3116.c

@@ -433,10 +433,11 @@ static int ark3116_tiocmset(struct tty_struct *tty,
 	return 0;
 }
 
-static void ark3116_break_ctl(struct tty_struct *tty, int break_state)
+static int ark3116_break_ctl(struct tty_struct *tty, int break_state)
 {
 	struct usb_serial_port *port = tty->driver_data;
 	struct ark3116_private *priv = usb_get_serial_port_data(port);
+	int ret;
 
 	/* LCR is also used for other things: protect access */
 	mutex_lock(&priv->hw_lock);
@@ -446,9 +447,11 @@ static void ark3116_break_ctl(struct tty_struct *tty, int break_state)
 	else
 		priv->lcr &= ~UART_LCR_SBC;
 
-	ark3116_write_reg(port->serial, UART_LCR, priv->lcr);
+	ret = ark3116_write_reg(port->serial, UART_LCR, priv->lcr);
 
 	mutex_unlock(&priv->hw_lock);
+
+	return ret;
 }
 
 static void ark3116_update_msr(struct usb_serial_port *port, __u8 msr)

drivers/usb/serial/belkin_sa.c

@@ -46,7 +46,7 @@ static void belkin_sa_process_read_urb(struct urb *urb);
 static void belkin_sa_set_termios(struct tty_struct *tty,
 				  struct usb_serial_port *port,
 				  const struct ktermios *old_termios);
-static void belkin_sa_break_ctl(struct tty_struct *tty, int break_state);
+static int belkin_sa_break_ctl(struct tty_struct *tty, int break_state);
 static int  belkin_sa_tiocmget(struct tty_struct *tty);
 static int  belkin_sa_tiocmset(struct tty_struct *tty,
 					unsigned int set, unsigned int clear);
@@ -399,13 +399,19 @@ static void belkin_sa_set_termios(struct tty_struct *tty,
 	spin_unlock_irqrestore(&priv->lock, flags);
 }
 
-static void belkin_sa_break_ctl(struct tty_struct *tty, int break_state)
+static int belkin_sa_break_ctl(struct tty_struct *tty, int break_state)
 {
 	struct usb_serial_port *port = tty->driver_data;
 	struct usb_serial *serial = port->serial;
+	int ret;
 
-	if (BSA_USB_CMD(BELKIN_SA_SET_BREAK_REQUEST, break_state ? 1 : 0) < 0)
+	ret = BSA_USB_CMD(BELKIN_SA_SET_BREAK_REQUEST, break_state ? 1 : 0);
+	if (ret < 0) {
 		dev_err(&port->dev, "Set break_ctl %d\n", break_state);
+		return ret;
+	}
+
+	return 0;
 }
 
 static int belkin_sa_tiocmget(struct tty_struct *tty)

drivers/usb/serial/ch341.c

@@ -562,12 +562,12 @@ static void ch341_set_termios(struct tty_struct *tty,
  * TCSBRKP. Due to how the simulation is implemented the duration can't be
  * controlled. The duration is always about (1s / 46bd * 9bit) = 196ms.
  */
-static void ch341_simulate_break(struct tty_struct *tty, int break_state)
+static int ch341_simulate_break(struct tty_struct *tty, int break_state)
 {
 	struct usb_serial_port *port = tty->driver_data;
 	struct ch341_private *priv = usb_get_serial_port_data(port);
 	unsigned long now, delay;
-	int r;
+	int r, r2;
 
 	if (break_state != 0) {
 		dev_dbg(&port->dev, "enter break state requested\n");
@@ -599,7 +599,7 @@ static void ch341_simulate_break(struct tty_struct *tty, int break_state)
 		 */
 		priv->break_end = jiffies + (11 * HZ / CH341_MIN_BPS);
 
-		return;
+		return 0;
 	}
 
 	dev_dbg(&port->dev, "leave break state requested\n");
@@ -615,17 +615,22 @@ static void ch341_simulate_break(struct tty_struct *tty, int break_state)
 		schedule_timeout_interruptible(delay);
 	}
 
+	r = 0;
 restore:
 	/* Restore original baud rate */
-	r = ch341_set_baudrate_lcr(port->serial->dev, priv, priv->baud_rate,
-				   priv->lcr);
-	if (r < 0)
+	r2 = ch341_set_baudrate_lcr(port->serial->dev, priv, priv->baud_rate,
+			priv->lcr);
+	if (r2 < 0) {
 		dev_err(&port->dev,
 			"restoring original baud rate of %u failed: %d\n",
-			priv->baud_rate, r);
+			priv->baud_rate, r2);
+		return r2;
+	}
+
+	return r;
 }
 
-static void ch341_break_ctl(struct tty_struct *tty, int break_state)
+static int ch341_break_ctl(struct tty_struct *tty, int break_state)
 {
 	const uint16_t ch341_break_reg =
 			((uint16_t) CH341_REG_LCR << 8) | CH341_REG_BREAK;
@@ -635,17 +640,17 @@ static void ch341_break_ctl(struct tty_struct *tty, int break_state)
 	uint16_t reg_contents;
 	uint8_t break_reg[2];
 
-	if (priv->quirks & CH341_QUIRK_SIMULATE_BREAK) {
-		ch341_simulate_break(tty, break_state);
-		return;
-	}
+	if (priv->quirks & CH341_QUIRK_SIMULATE_BREAK)
+		return ch341_simulate_break(tty, break_state);
 
 	r = ch341_control_in(port->serial->dev, CH341_REQ_READ_REG,
 			ch341_break_reg, 0, break_reg, 2);
 	if (r) {
 		dev_err(&port->dev, "%s - USB control read error (%d)\n",
 				__func__, r);
-		return;
+		if (r > 0)
+			r = -EIO;
+		return r;
 	}
 	dev_dbg(&port->dev, "%s - initial ch341 break register contents - reg1: %x, reg2: %x\n",
 		__func__, break_reg[0], break_reg[1]);
@@ -663,9 +668,13 @@ static void ch341_break_ctl(struct tty_struct *tty, int break_state)
 	reg_contents = get_unaligned_le16(break_reg);
 	r = ch341_control_out(port->serial->dev, CH341_REQ_WRITE_REG,
 			ch341_break_reg, reg_contents);
-	if (r < 0)
+	if (r < 0) {
 		dev_err(&port->dev, "%s - USB control write error (%d)\n",
 				__func__, r);
+		return r;
+	}
+
+	return 0;
 }
 
 static int ch341_tiocmset(struct tty_struct *tty,

drivers/usb/serial/cp210x.c

@@ -39,7 +39,7 @@ static int cp210x_tiocmget(struct tty_struct *);
 static int cp210x_tiocmset(struct tty_struct *, unsigned int, unsigned int);
 static int cp210x_tiocmset_port(struct usb_serial_port *port,
 		unsigned int, unsigned int);
-static void cp210x_break_ctl(struct tty_struct *, int);
+static int cp210x_break_ctl(struct tty_struct *, int);
 static int cp210x_attach(struct usb_serial *);
 static void cp210x_disconnect(struct usb_serial *);
 static void cp210x_release(struct usb_serial *);
@@ -1434,7 +1434,7 @@ static int cp210x_tiocmget(struct tty_struct *tty)
 	return result;
 }
 
-static void cp210x_break_ctl(struct tty_struct *tty, int break_state)
+static int cp210x_break_ctl(struct tty_struct *tty, int break_state)
 {
 	struct usb_serial_port *port = tty->driver_data;
 	u16 state;
@@ -1443,9 +1443,11 @@ static void cp210x_break_ctl(struct tty_struct *tty, int break_state)
 		state = BREAK_OFF;
 	else
 		state = BREAK_ON;
+
 	dev_dbg(&port->dev, "%s - turning break %s\n", __func__,
 		state == BREAK_OFF ? "off" : "on");
-	cp210x_write_u16_reg(port, CP210X_SET_BREAK, state);
+
+	return cp210x_write_u16_reg(port, CP210X_SET_BREAK, state);
 }
 
 #ifdef CONFIG_GPIOLIB

drivers/usb/serial/digi_acceleport.c

@@ -217,7 +217,7 @@ static void digi_rx_unthrottle(struct tty_struct *tty);
 static void digi_set_termios(struct tty_struct *tty,
 			     struct usb_serial_port *port,
 			     const struct ktermios *old_termios);
-static void digi_break_ctl(struct tty_struct *tty, int break_state);
+static int digi_break_ctl(struct tty_struct *tty, int break_state);
 static int digi_tiocmget(struct tty_struct *tty);
 static int digi_tiocmset(struct tty_struct *tty, unsigned int set,
 		unsigned int clear);
@@ -839,7 +839,7 @@ static void digi_set_termios(struct tty_struct *tty,
 }
 
 
-static void digi_break_ctl(struct tty_struct *tty, int break_state)
+static int digi_break_ctl(struct tty_struct *tty, int break_state)
 {
 	struct usb_serial_port *port = tty->driver_data;
 	unsigned char buf[4];
@@ -848,7 +848,8 @@ static void digi_break_ctl(struct tty_struct *tty, int break_state)
 	buf[1] = 2;				/* length */
 	buf[2] = break_state ? 1 : 0;
 	buf[3] = 0;				/* pad */
-	digi_write_inb_command(port, buf, 4, 0);
+
+	return digi_write_inb_command(port, buf, 4, 0);
 }
 
 

drivers/usb/serial/f81232.c

@@ -448,7 +448,7 @@ static void f81534a_process_read_urb(struct urb *urb)
 	tty_flip_buffer_push(&port->port);
 }
 
-static void f81232_break_ctl(struct tty_struct *tty, int break_state)
+static int f81232_break_ctl(struct tty_struct *tty, int break_state)
 {
 	struct usb_serial_port *port = tty->driver_data;
 	struct f81232_private *priv = usb_get_serial_port_data(port);
@@ -467,6 +467,8 @@ static void f81232_break_ctl(struct tty_struct *tty, int break_state)
 		dev_err(&port->dev, "set break failed: %d\n", status);
 
 	mutex_unlock(&priv->lock);
+
+	return status;
 }
 
 static int f81232_find_clk(speed_t baudrate)

drivers/usb/serial/f81534.c

@@ -656,7 +656,7 @@ static int f81534_set_port_config(struct usb_serial_port *port,
 	return status;
 }
 
-static void f81534_break_ctl(struct tty_struct *tty, int break_state)
+static int f81534_break_ctl(struct tty_struct *tty, int break_state)
 {
 	struct usb_serial_port *port = tty->driver_data;
 	struct f81534_port_private *port_priv = usb_get_serial_port_data(port);
@@ -675,6 +675,8 @@ static void f81534_break_ctl(struct tty_struct *tty, int break_state)
 		dev_err(&port->dev, "set break failed: %d\n", status);
 
 	mutex_unlock(&port_priv->lcr_mutex);
+
+	return status;
 }
 
 static int f81534_update_mctrl(struct usb_serial_port *port, unsigned int set,

drivers/usb/serial/ftdi_sio.c

@@ -2550,11 +2550,12 @@ static void ftdi_process_read_urb(struct urb *urb)
 		tty_flip_buffer_push(&port->port);
 }
 
-static void ftdi_break_ctl(struct tty_struct *tty, int break_state)
+static int ftdi_break_ctl(struct tty_struct *tty, int break_state)
 {
 	struct usb_serial_port *port = tty->driver_data;
 	struct ftdi_private *priv = usb_get_serial_port_data(port);
 	u16 value;
+	int ret;
 
 	/* break_state = -1 to turn on break, and 0 to turn off break */
 	/* see drivers/char/tty_io.c to see it used */
@@ -2565,19 +2566,22 @@ static void ftdi_break_ctl(struct tty_struct *tty, int break_state)
 	else
 		value = priv->last_set_data_value;
 
-	if (usb_control_msg(port->serial->dev,
+	ret = usb_control_msg(port->serial->dev,
 			usb_sndctrlpipe(port->serial->dev, 0),
 			FTDI_SIO_SET_DATA_REQUEST,
 			FTDI_SIO_SET_DATA_REQUEST_TYPE,
 			value, priv->channel,
-			NULL, 0, WDR_TIMEOUT) < 0) {
+			NULL, 0, WDR_TIMEOUT);
+	if (ret < 0) {
 		dev_err(&port->dev, "%s FAILED to enable/disable break state (state was %d)\n",
 			__func__, break_state);
+		return ret;
 	}
 
 	dev_dbg(&port->dev, "%s break state is %d - urb is %d\n", __func__,
 		break_state, value);
 
+	return 0;
 }
 
 static bool ftdi_tx_empty(struct usb_serial_port *port)

drivers/usb/serial/io_edgeport.c

@@ -1560,12 +1560,12 @@ static int edge_ioctl(struct tty_struct *tty,
  * SerialBreak
  *	this function sends a break to the port
  *****************************************************************************/
-static void edge_break(struct tty_struct *tty, int break_state)
+static int edge_break(struct tty_struct *tty, int break_state)
 {
 	struct usb_serial_port *port = tty->driver_data;
 	struct edgeport_port *edge_port = usb_get_serial_port_data(port);
 	struct edgeport_serial *edge_serial = usb_get_serial_data(port->serial);
-	int status;
+	int status = 0;
 
 	if (!edge_serial->is_epic ||
 	    edge_serial->epic_descriptor.Supports.IOSPChase) {
@@ -1597,6 +1597,8 @@ static void edge_break(struct tty_struct *tty, int break_state)
 			dev_dbg(&port->dev, "%s - error sending break set/clear command.\n",
 				__func__);
 	}
+
+	return status;
 }
 
 

drivers/usb/serial/io_ti.c

@@ -2421,7 +2421,7 @@ static int edge_tiocmget(struct tty_struct *tty)
 	return result;
 }
 
-static void edge_break(struct tty_struct *tty, int break_state)
+static int edge_break(struct tty_struct *tty, int break_state)
 {
 	struct usb_serial_port *port = tty->driver_data;
 	struct edgeport_port *edge_port = usb_get_serial_port_data(port);
@@ -2430,10 +2430,15 @@ static void edge_break(struct tty_struct *tty, int break_state)
 
 	if (break_state == -1)
 		bv = 1;	/* On */
+
 	status = ti_do_config(edge_port, UMPC_SET_CLR_BREAK, bv);
-	if (status)
+	if (status) {
 		dev_dbg(&port->dev, "%s - error %d sending break set/clear command.\n",
 			__func__, status);
+		return status;
+	}
+
+	return 0;
 }
 
 static void edge_heartbeat_schedule(struct edgeport_serial *edge_serial)