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Commit 0943d8ea authored by Johan Hovold's avatar Johan Hovold Committed by Greg Kroah-Hartman
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USB: cdc-acm: use tty-port dtr_rts 



Add dtr_rts tty-port operation which implements proper DTR/RTS handling
(e.g. only lower DTR/RTS during shutdown if HUPCL is set).

Note that modem-control locking still needs to be added throughout the
driver.

Signed-off-by: default avatarJohan Hovold <jhovold@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 308fee18

drivers/usb/class/cdc-acm.c

+20 −12
Original line number Diff line number Diff line
@@ -504,6 +504,25 @@ static int acm_tty_open(struct tty_struct *tty, struct file *filp) 
	return tty_port_open(&acm->port, tty, filp);

}



static void acm_port_dtr_rts(struct tty_port *port, int raise)

{

	struct acm *acm = container_of(port, struct acm, port);

	int val;

	int res;



	if (raise)

		val = ACM_CTRL_DTR | ACM_CTRL_RTS;

	else

		val = 0;



	/* FIXME: add missing ctrlout locking throughout driver */

	acm->ctrlout = val;



	res = acm_set_control(acm, val);

	if (res && (acm->ctrl_caps & USB_CDC_CAP_LINE))

		dev_err(&acm->control->dev, "failed to set dtr/rts\n");

}



static int acm_port_activate(struct tty_port *port, struct tty_struct *tty)

{

	struct acm *acm = container_of(port, struct acm, port);
@@ -535,11 +554,6 @@ static int acm_port_activate(struct tty_port *port, struct tty_struct *tty) 
		goto error_submit_urb;

	}



	acm->ctrlout = ACM_CTRL_DTR | ACM_CTRL_RTS;

	retval = acm_set_control(acm, acm->ctrlout);

	if (retval < 0 && (acm->ctrl_caps & USB_CDC_CAP_LINE))

		goto error_set_control;



	/*

	 * Unthrottle device in case the TTY was closed while throttled.

	 */
@@ -561,9 +575,6 @@ static int acm_port_activate(struct tty_port *port, struct tty_struct *tty) 
error_submit_read_urbs:

	for (i = 0; i < acm->rx_buflimit; i++)

		usb_kill_urb(acm->read_urbs[i]);

	acm->ctrlout = 0;

	acm_set_control(acm, acm->ctrlout);

error_set_control:

	usb_kill_urb(acm->ctrlurb);

error_submit_urb:

	usb_autopm_put_interface(acm->control);
@@ -595,8 +606,6 @@ static void acm_port_shutdown(struct tty_port *port) 


	dev_dbg(&acm->control->dev, "%s\n", __func__);



	acm_set_control(acm, acm->ctrlout = 0);



	/*

	 * Need to grab write_lock to prevent race with resume, but no need to

	 * hold it due to the tty-port initialised flag.
@@ -992,6 +1001,7 @@ static void acm_tty_set_termios(struct tty_struct *tty, 
}



static const struct tty_port_operations acm_port_ops = {

	.dtr_rts = acm_port_dtr_rts,

	.shutdown = acm_port_shutdown,

	.activate = acm_port_activate,

	.destruct = acm_port_destruct,
@@ -1429,8 +1439,6 @@ static int acm_probe(struct usb_interface *intf, 


	dev_info(&intf->dev, "ttyACM%d: USB ACM device\n", minor);



	acm_set_control(acm, acm->ctrlout);



	acm->line.dwDTERate = cpu_to_le32(9600);

	acm->line.bDataBits = 8;

	acm_set_line(acm, &acm->line);