USB: cypress_m8: 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.

Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/serial/cypress_m8.c b/drivers/usb/serial/cypress_m8.c
index 07e0033..763d1c5 100644 (file)
--- a/drivers/usb/serial/cypress_m8.c
+++ b/drivers/usb/serial/cypress_m8.c
@@ -113,7 +113,7 @@ struct cypress_private {
        int baud_rate;                     /* stores current baud rate in
                                              integer form */
        int isthrottled;                   /* if throttled, discard reads */
-       char prev_status, diff_status;     /* used for TIOCMIWAIT */
+       char prev_status;                  /* used for TIOCMIWAIT */
        /* we pass a pointer to this as the argument sent to
           cypress_set_termios old_termios */
        struct ktermios tmp_termios;       /* stores the old termios settings */
@@ -136,7 +136,6 @@ static void cypress_set_termios(struct tty_struct *tty,
 static int  cypress_tiocmget(struct tty_struct *tty);
 static int  cypress_tiocmset(struct tty_struct *tty,
                        unsigned int set, unsigned int clear);
-static int  cypress_tiocmiwait(struct tty_struct *tty, unsigned long arg);
 static int  cypress_chars_in_buffer(struct tty_struct *tty);
 static void cypress_throttle(struct tty_struct *tty);
 static void cypress_unthrottle(struct tty_struct *tty);
@@ -162,7 +161,7 @@ static struct usb_serial_driver cypress_earthmate_device = {
        .set_termios =                  cypress_set_termios,
        .tiocmget =                     cypress_tiocmget,
        .tiocmset =                     cypress_tiocmset,
-       .tiocmiwait =                   cypress_tiocmiwait,
+       .tiocmiwait =                   usb_serial_generic_tiocmiwait,
        .chars_in_buffer =              cypress_chars_in_buffer,
        .throttle =                     cypress_throttle,
        .unthrottle =                   cypress_unthrottle,
@@ -188,7 +187,7 @@ static struct usb_serial_driver cypress_hidcom_device = {
        .set_termios =                  cypress_set_termios,
        .tiocmget =                     cypress_tiocmget,
        .tiocmset =                     cypress_tiocmset,
-       .tiocmiwait =                   cypress_tiocmiwait,
+       .tiocmiwait =                   usb_serial_generic_tiocmiwait,
        .chars_in_buffer =              cypress_chars_in_buffer,
        .throttle =                     cypress_throttle,
        .unthrottle =                   cypress_unthrottle,
@@ -214,7 +213,7 @@ static struct usb_serial_driver cypress_ca42v2_device = {
        .set_termios =                  cypress_set_termios,
        .tiocmget =                     cypress_tiocmget,
        .tiocmset =                     cypress_tiocmset,
-       .tiocmiwait =                   cypress_tiocmiwait,
+       .tiocmiwait =                   usb_serial_generic_tiocmiwait,
        .chars_in_buffer =              cypress_chars_in_buffer,
        .throttle =                     cypress_throttle,
        .unthrottle =                   cypress_unthrottle,
@@ -864,45 +863,6 @@ static int cypress_tiocmset(struct tty_struct *tty,
        return cypress_write(tty, port, NULL, 0);
 }
 
-
-static int cypress_tiocmiwait(struct tty_struct *tty, unsigned long arg)
-{
-       struct usb_serial_port *port = tty->driver_data;
-       struct cypress_private *priv = usb_get_serial_port_data(port);
-       char diff;
-
-       for (;;) {
-               interruptible_sleep_on(&port->port.delta_msr_wait);
-               /* see if a signal did it */
-               if (signal_pending(current))
-                       return -ERESTARTSYS;
-
-               if (port->serial->disconnected)
-                       return -EIO;
-
-               diff = priv->diff_status;
-               if (diff == 0)
-                       return -EIO; /* no change => error */
-
-               /* consume all events */
-               priv->diff_status = 0;
-
-               /* return 0 if caller wanted to know about
-                  these bits */
-               if (((arg & TIOCM_RNG) && (diff & UART_RI))  ||
-                       ((arg & TIOCM_DSR) && (diff & UART_DSR)) ||
-                       ((arg & TIOCM_CD)  && (diff & UART_CD))  ||
-                       ((arg & TIOCM_CTS) && (diff & UART_CTS)))
-                       return 0;
-               /* otherwise caller can't care less about what
-                * happened, and so we continue to wait for
-                * more events.
-                */
-       }
-
-       return 0;
-}
-
 static void cypress_set_termios(struct tty_struct *tty,
        struct usb_serial_port *port, struct ktermios *old_termios)
 {
@@ -1185,11 +1145,20 @@ static void cypress_read_int_callback(struct urb *urb)
        spin_lock_irqsave(&priv->lock, flags);
        /* check to see if status has changed */
        if (priv->current_status != priv->prev_status) {
-               priv->diff_status |= priv->current_status ^
-                       priv->prev_status;
+               u8 delta = priv->current_status ^ priv->prev_status;
+
+               if (delta & UART_MSR_MASK) {
+                       if (delta & UART_CTS)
+                               port->icount.cts++;
+                       if (delta & UART_DSR)
+                               port->icount.dsr++;
+                       if (delta & UART_RI)
+                               port->icount.rng++;
+                       if (delta & UART_CD)
+                               port->icount.dcd++;
 
-               if (priv->diff_status & UART_MSR_MASK)
                        wake_up_interruptible(&port->port.delta_msr_wait);
+               }
 
                priv->prev_status = priv->current_status;
        }