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Commit ab62a585 authored by Johan Hovold's avatar Johan Hovold Committed by Greg Kroah-Hartman
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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: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarJohan Hovold <jhovold@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 7603381e

drivers/usb/serial/cypress_m8.c

+16 −47
Original line number Diff line number Diff line
@@ -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;

	}