Commit 79fe6826 authored by Johan Hovold's avatar Johan Hovold
Browse files

USB: serial: keyspan_pda: refactor write-room handling 



Add helper to retrieve the available device transfer-buffer space.

Acked-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarJohan Hovold <johan@kernel.org>
parent 320f9028

drivers/usb/serial/keyspan_pda.c

+50 −63
Original line number Diff line number Diff line
@@ -98,6 +98,42 @@ static const struct usb_device_id id_table_fake_xircom[] = { 
};

#endif



static int keyspan_pda_get_write_room(struct keyspan_pda_private *priv)

{

	struct usb_serial_port *port = priv->port;

	struct usb_serial *serial = priv->serial;

	u8 *room;

	int rc;



	room = kmalloc(1, GFP_KERNEL);

	if (!room)

		return -ENOMEM;



	rc = usb_control_msg(serial->dev,

			     usb_rcvctrlpipe(serial->dev, 0),

			     6, /* write_room */

			     USB_TYPE_VENDOR | USB_RECIP_INTERFACE

			     | USB_DIR_IN,

			     0, /* value: 0 means "remaining room" */

			     0, /* index */

			     room,

			     1,

			     2000);

	if (rc != 1) {

		if (rc >= 0)

			rc = -EIO;

		dev_dbg(&port->dev, "roomquery failed: %d\n", rc);

		goto out_free;

	}



	dev_dbg(&port->dev, "roomquery says %d\n", *room);

	rc = *room;

out_free:

	kfree(room);



	return rc;

}



static void keyspan_pda_request_unthrottle(struct work_struct *work)

{

	struct keyspan_pda_private *priv =
@@ -436,7 +472,6 @@ static int keyspan_pda_tiocmset(struct tty_struct *tty, 
static int keyspan_pda_write(struct tty_struct *tty,

	struct usb_serial_port *port, const unsigned char *buf, int count)

{

	struct usb_serial *serial = port->serial;

	int request_unthrottle = 0;

	int rc = 0;

	struct keyspan_pda_private *priv;
@@ -479,38 +514,11 @@ static int keyspan_pda_write(struct tty_struct *tty, 
	   device how much room it really has.  This is done only on

	   scheduler time, since usb_control_msg() sleeps. */

	if (count > priv->tx_room && !in_interrupt()) {

		u8 *room;



		room = kmalloc(1, GFP_KERNEL);

		if (!room) {

			rc = -ENOMEM;

		rc = keyspan_pda_get_write_room(priv);

		if (rc < 0)

			goto exit;

		}



		rc = usb_control_msg(serial->dev,

				     usb_rcvctrlpipe(serial->dev, 0),

				     6, /* write_room */

				     USB_TYPE_VENDOR | USB_RECIP_INTERFACE

				     | USB_DIR_IN,

				     0, /* value: 0 means "remaining room" */

				     0, /* index */

				     room,

				     1,

				     2000);

		if (rc > 0) {

			dev_dbg(&port->dev, "roomquery says %d\n", *room);

			priv->tx_room = *room;

		}

		kfree(room);

		if (rc < 0) {

			dev_dbg(&port->dev, "roomquery failed\n");

			goto exit;

		}

		if (rc == 0) {

			dev_dbg(&port->dev, "roomquery returned 0 bytes\n");

			rc = -EIO; /* device didn't return any data */

			goto exit;

		}

		priv->tx_room = rc;

	}



	if (count >= priv->tx_room) {
@@ -614,48 +622,27 @@ static void keyspan_pda_dtr_rts(struct usb_serial_port *port, int on) 
static int keyspan_pda_open(struct tty_struct *tty,

					struct usb_serial_port *port)

{

	struct usb_serial *serial = port->serial;

	u8 *room;

	int rc = 0;

	struct keyspan_pda_private *priv;

	struct keyspan_pda_private *priv = usb_get_serial_port_data(port);

	int rc;



	/* find out how much room is in the Tx ring */

	room = kmalloc(1, GFP_KERNEL);

	if (!room)

		return -ENOMEM;

	rc = keyspan_pda_get_write_room(priv);

	if (rc < 0)

		return rc;



	rc = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),

			     6, /* write_room */

			     USB_TYPE_VENDOR | USB_RECIP_INTERFACE

			     | USB_DIR_IN,

			     0, /* value */

			     0, /* index */

			     room,

			     1,

			     2000);

	if (rc < 0) {

		dev_dbg(&port->dev, "%s - roomquery failed\n", __func__);

		goto error;

	}

	if (rc == 0) {

		dev_dbg(&port->dev, "%s - roomquery returned 0 bytes\n", __func__);

		rc = -EIO;

		goto error;

	}

	priv = usb_get_serial_port_data(port);

	priv->tx_room = *room;

	priv->tx_throttled = *room ? 0 : 1;

	priv->tx_room = rc;

	priv->tx_throttled = rc ? 0 : 1;



	/*Start reading from the device*/

	rc = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);

	if (rc) {

		dev_dbg(&port->dev, "%s - usb_submit_urb(read int) failed\n", __func__);

		goto error;

	}

error:

	kfree(room);

		return rc;

	}



	return 0;

}



static void keyspan_pda_close(struct usb_serial_port *port)

{

	struct keyspan_pda_private *priv = usb_get_serial_port_data(port);