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Commit 3f550431 authored by Johan Hovold's avatar Johan Hovold Committed by Greg Kroah-Hartman
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USB: ch341: fix TIOCMIWAIT and disconnect 



Use tty-port modem-status-change wait queue on which processes are woken
up at hangup and disconnect.

Currently a process waiting on modem-status changes will not be woken on
device disconnect as wake up was only done in dtr_rts which isn't
guaranteed to be called (e.g. if HUPCL is not set).

Also remove the redundant wake-up call from dtr_rts.

Signed-off-by: default avatarJohan Hovold <jhovold@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 7bb98f0e

drivers/usb/serial/ch341.c

+2 −3
Original line number Original line Diff line number Diff line
@@ -296,7 +296,6 @@ static void ch341_dtr_rts(struct usb_serial_port *port, int on) 
		priv->line_control &= ~(CH341_BIT_RTS | CH341_BIT_DTR);

		priv->line_control &= ~(CH341_BIT_RTS | CH341_BIT_DTR);

	spin_unlock_irqrestore(&priv->lock, flags);

	spin_unlock_irqrestore(&priv->lock, flags);

	ch341_set_handshake(port->serial->dev, priv->line_control);

	ch341_set_handshake(port->serial->dev, priv->line_control);

	wake_up_interruptible(&port->delta_msr_wait);

}

}





static void ch341_close(struct usb_serial_port *port)

static void ch341_close(struct usb_serial_port *port)
@@ -489,7 +488,7 @@ static void ch341_read_int_callback(struct urb *urb) 
			tty_kref_put(tty);

			tty_kref_put(tty);

		}

		}





		wake_up_interruptible(&port->delta_msr_wait);

		wake_up_interruptible(&port->port.delta_msr_wait);

	}

	}





exit:

exit:
@@ -516,7 +515,7 @@ static int ch341_tiocmiwait(struct tty_struct *tty, unsigned long arg) 
	spin_unlock_irqrestore(&priv->lock, flags);

	spin_unlock_irqrestore(&priv->lock, flags);





	while (!multi_change) {

	while (!multi_change) {

		interruptible_sleep_on(&port->delta_msr_wait);

		interruptible_sleep_on(&port->port.delta_msr_wait);

		/* see if a signal did it */

		/* see if a signal did it */

		if (signal_pending(current))

		if (signal_pending(current))

			return -ERESTARTSYS;

			return -ERESTARTSYS;