USB: ark3116: switch to generic TIOCMIWAIT implementation
authorJohan Hovold <jhovold@gmail.com>
Thu, 21 Mar 2013 11:36:59 +0000 (12:36 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Mon, 25 Mar 2013 20:50:52 +0000 (13:50 -0700)
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/ark3116.c

index ed3f6b884073f4ea95c4ceba065fca57851a6ebd..3b16118cbf62d7d8be032f6a243a39fd5965a5be 100644 (file)
@@ -426,33 +426,6 @@ static int ark3116_ioctl(struct tty_struct *tty,
                if (copy_from_user(&serstruct, user_arg, sizeof(serstruct)))
                        return -EFAULT;
                return 0;
-       case TIOCMIWAIT:
-               for (;;) {
-                       struct async_icount prev = port->icount;
-                       interruptible_sleep_on(&port->delta_msr_wait);
-                       /* see if a signal did it */
-                       if (signal_pending(current))
-                               return -ERESTARTSYS;
-
-                       if (port->serial->disconnected)
-                               return -EIO;
-
-                       if ((prev.rng == port->icount.rng) &&
-                           (prev.dsr == port->icount.dsr) &&
-                           (prev.dcd == port->icount.dcd) &&
-                           (prev.cts == port->icount.cts))
-                               return -EIO;
-                       if ((arg & TIOCM_RNG &&
-                            (prev.rng != port->icount.rng)) ||
-                           (arg & TIOCM_DSR &&
-                            (prev.dsr != port->icount.dsr)) ||
-                           (arg & TIOCM_CD  &&
-                            (prev.dcd != port->icount.dcd)) ||
-                           (arg & TIOCM_CTS &&
-                            (prev.cts != port->icount.cts)))
-                               return 0;
-               }
-               break;
        }
 
        return -ENOIOCTLCMD;
@@ -557,7 +530,7 @@ static void ark3116_update_msr(struct usb_serial_port *port, __u8 msr)
                        port->icount.dcd++;
                if (msr & UART_MSR_TERI)
                        port->icount.rng++;
-               wake_up_interruptible(&port->delta_msr_wait);
+               wake_up_interruptible(&port->port.delta_msr_wait);
        }
 }
 
@@ -697,6 +670,7 @@ static struct usb_serial_driver ark3116_device = {
        .ioctl =                ark3116_ioctl,
        .tiocmget =             ark3116_tiocmget,
        .tiocmset =             ark3116_tiocmset,
+       .tiocmiwait =           usb_serial_generic_tiocmiwait,
        .get_icount =           usb_serial_generic_get_icount,
        .open =                 ark3116_open,
        .close =                ark3116_close,