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Commit 5e409a26 authored by Johan Hovold's avatar Johan Hovold Committed by Greg Kroah-Hartman
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USB: ch341: 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 d984fe91

drivers/usb/serial/ch341.c

+8 −41
Original line number Diff line number Diff line
@@ -463,7 +463,14 @@ static void ch341_update_line_status(struct usb_serial_port *port, 
	if (!delta)

		return;



	if (delta & CH341_BIT_CTS)

		port->icount.cts++;

	if (delta & CH341_BIT_DSR)

		port->icount.dsr++;

	if (delta & CH341_BIT_RI)

		port->icount.rng++;

	if (delta & CH341_BIT_DCD) {

		port->icount.dcd++;

		tty = tty_port_tty_get(&port->port);

		if (tty) {

			usb_serial_handle_dcd_change(port, tty,
@@ -510,46 +517,6 @@ exit: 
			__func__, status);

}



static int ch341_tiocmiwait(struct tty_struct *tty, unsigned long arg)

{

	struct usb_serial_port *port = tty->driver_data;

	struct ch341_private *priv = usb_get_serial_port_data(port);

	unsigned long flags;

	u8 prevstatus;

	u8 status;

	u8 changed;



	spin_lock_irqsave(&priv->lock, flags);

	prevstatus = priv->line_status;

	spin_unlock_irqrestore(&priv->lock, flags);



	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;



		spin_lock_irqsave(&priv->lock, flags);

		status = priv->line_status;

		spin_unlock_irqrestore(&priv->lock, flags);



		changed = prevstatus ^ status;



		if (((arg & TIOCM_RNG) && (changed & CH341_BIT_RI)) ||

		    ((arg & TIOCM_DSR) && (changed & CH341_BIT_DSR)) ||

		    ((arg & TIOCM_CD)  && (changed & CH341_BIT_DCD)) ||

		    ((arg & TIOCM_CTS) && (changed & CH341_BIT_CTS))) {

			return 0;

		}

		prevstatus = status;

	}



	return 0;

}



static int ch341_tiocmget(struct tty_struct *tty)

{

	struct usb_serial_port *port = tty->driver_data;
@@ -603,7 +570,7 @@ static struct usb_serial_driver ch341_device = { 
	.break_ctl         = ch341_break_ctl,

	.tiocmget          = ch341_tiocmget,

	.tiocmset          = ch341_tiocmset,

	.tiocmiwait        = ch341_tiocmiwait,

	.tiocmiwait        = usb_serial_generic_tiocmiwait,

	.read_int_callback = ch341_read_int_callback,

	.port_probe        = ch341_port_probe,

	.port_remove       = ch341_port_remove,