USB: ti_usb_3410_5052: switch to generic TIOCMIWAIT implementation

Switch to the generic TIOCMIWAIT implementation which does not suffer
from the races involved when using the deprecated sleep_on functions.

This also fixes the issue with processes waiting for
modem-status-changes not being woken up at disconnect.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/serial/ti_usb_3410_5052.c

@@ -232,6 +232,7 @@ static struct usb_serial_driver ti_1port_device = {
 	.set_termios		= ti_set_termios,
 	.tiocmget		= ti_tiocmget,
 	.tiocmset		= ti_tiocmset,
+	.tiocmiwait		= usb_serial_generic_tiocmiwait,
 	.get_icount		= usb_serial_generic_get_icount,
 	.break_ctl		= ti_break,
 	.read_int_callback	= ti_interrupt_callback,
@@ -262,6 +263,7 @@ static struct usb_serial_driver ti_2port_device = {
 	.set_termios		= ti_set_termios,
 	.tiocmget		= ti_tiocmget,
 	.tiocmset		= ti_tiocmset,
+	.tiocmiwait		= usb_serial_generic_tiocmiwait,
 	.get_icount		= usb_serial_generic_get_icount,
 	.break_ctl		= ti_break,
 	.read_int_callback	= ti_interrupt_callback,
@@ -731,8 +733,6 @@ static int ti_ioctl(struct tty_struct *tty,
 {
 	struct usb_serial_port *port = tty->driver_data;
 	struct ti_port *tport = usb_get_serial_port_data(port);
-	struct async_icount cnow;
-	struct async_icount cprev;
 
 	dev_dbg(&port->dev, "%s - cmd = 0x%04X\n", __func__, cmd);
 
@@ -748,29 +748,6 @@ static int ti_ioctl(struct tty_struct *tty,
 		dev_dbg(&port->dev, "%s - TIOCSSERIAL\n", __func__);
 		return ti_set_serial_info(tty, tport,
 				(struct serial_struct __user *)arg);
-	case TIOCMIWAIT:
-		dev_dbg(&port->dev, "%s - TIOCMIWAIT\n", __func__);
-		cprev = port->icount;
-		while (1) {
-			interruptible_sleep_on(&port->delta_msr_wait);
-			if (signal_pending(current))
-				return -ERESTARTSYS;
-
-			if (port->serial->disconnected)
-				return -EIO;
-
-			cnow = port->icount;
-			if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr &&
-			    cnow.dcd == cprev.dcd && cnow.cts == cprev.cts)
-				return -EIO; /* no change => error */
-			if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
-			    ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
-			    ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
-			    ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts)))
-				return 0;
-			cprev = cnow;
-		}
-		break;
 	}
 	return -ENOIOCTLCMD;
 }
@@ -1364,7 +1341,7 @@ static void ti_handle_new_msr(struct ti_port *tport, __u8 msr)
 			icount->dcd++;
 		if (msr & TI_MSR_DELTA_RI)
 			icount->rng++;
-		wake_up_interruptible(&tport->tp_port->delta_msr_wait);
+		wake_up_interruptible(&tport->tp_port->port.delta_msr_wait);
 		spin_unlock_irqrestore(&tport->tp_lock, flags);
 	}