USB: io_ti: switch to generic TIOCMIWAIT implementation
authorJohan Hovold <jhovold@gmail.com>
Thu, 21 Mar 2013 11:37:10 +0000 (12:37 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Mon, 25 Mar 2013 20:50:53 +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/io_ti.c

index fb9e664..8914002 100644 (file)
@@ -86,6 +86,7 @@ struct edgeport_port {
        int baud_rate;
        int close_pending;
        int lsr_event;
+
        struct edgeport_serial  *edge_serial;
        struct usb_serial_port  *port;
        __u8 bUartMode;         /* Port type, 0: RS232, etc. */
@@ -1455,7 +1456,7 @@ static void handle_new_msr(struct edgeport_port *edge_port, __u8 msr)
                        icount->dcd++;
                if (msr & EDGEPORT_MSR_DELTA_RI)
                        icount->rng++;
-               wake_up_interruptible(&edge_port->port->delta_msr_wait);
+               wake_up_interruptible(&edge_port->port->port.delta_msr_wait);
        }
 
        /* Save the new modem status */
@@ -2392,8 +2393,6 @@ static int edge_ioctl(struct tty_struct *tty,
 {
        struct usb_serial_port *port = tty->driver_data;
        struct edgeport_port *edge_port = usb_get_serial_port_data(port);
-       struct async_icount cnow;
-       struct async_icount cprev;
 
        dev_dbg(&port->dev, "%s - port %d, cmd = 0x%x\n", __func__, port->number, cmd);
 
@@ -2402,32 +2401,6 @@ static int edge_ioctl(struct tty_struct *tty,
                dev_dbg(&port->dev, "%s - TIOCGSERIAL\n", __func__);
                return get_serial_info(edge_port,
                                (struct serial_struct __user *) arg);
-       case TIOCMIWAIT:
-               dev_dbg(&port->dev, "%s - TIOCMIWAIT\n", __func__);
-               cprev = edge_port->port->icount;
-               while (1) {
-                       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;
-
-                       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;
-               }
-               /* not reached */
-               break;
        }
        return -ENOIOCTLCMD;
 }
@@ -2522,7 +2495,6 @@ static int edge_port_remove(struct usb_serial_port *port)
        struct edgeport_port *edge_port;
 
        edge_port = usb_get_serial_port_data(port);
-
        edge_remove_sysfs_attrs(port);
        kfifo_free(&edge_port->write_fifo);
        kfree(edge_port);
@@ -2594,6 +2566,7 @@ static struct usb_serial_driver edgeport_1port_device = {
        .set_termios            = edge_set_termios,
        .tiocmget               = edge_tiocmget,
        .tiocmset               = edge_tiocmset,
+       .tiocmiwait             = usb_serial_generic_tiocmiwait,
        .get_icount             = usb_serial_generic_get_icount,
        .write                  = edge_write,
        .write_room             = edge_write_room,
@@ -2625,6 +2598,7 @@ static struct usb_serial_driver edgeport_2port_device = {
        .set_termios            = edge_set_termios,
        .tiocmget               = edge_tiocmget,
        .tiocmset               = edge_tiocmset,
+       .tiocmiwait             = usb_serial_generic_tiocmiwait,
        .get_icount             = usb_serial_generic_get_icount,
        .write                  = edge_write,
        .write_room             = edge_write_room,