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Commit 684c6e30 authored by Johan Hovold's avatar Johan Hovold Committed by Greg Kroah-Hartman
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USB: pl2303: switch to generic write implementation



Replace custom fifo-based write implementation with the generic
kfifo-based one.

Signed-off-by: default avatarJohan Hovold <jhovold@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 50a5f70c
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+4 −326
Original line number Diff line number Diff line
@@ -40,16 +40,6 @@ static int debug;

#define PL2303_CLOSING_WAIT	(30*HZ)

#define PL2303_BUF_SIZE		1024
#define PL2303_TMP_BUF_SIZE	1024

struct pl2303_buf {
	unsigned int	buf_size;
	char		*buf_buf;
	char		*buf_get;
	char		*buf_put;
};

static const struct usb_device_id id_table[] = {
	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID) },
	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_RSAQ2) },
@@ -157,173 +147,12 @@ enum pl2303_type {

struct pl2303_private {
	spinlock_t lock;
	struct pl2303_buf *buf;
	int write_urb_in_use;
	wait_queue_head_t delta_msr_wait;
	u8 line_control;
	u8 line_status;
	enum pl2303_type type;
};

/*
 * pl2303_buf_alloc
 *
 * Allocate a circular buffer and all associated memory.
 */
static struct pl2303_buf *pl2303_buf_alloc(unsigned int size)
{
	struct pl2303_buf *pb;

	if (size == 0)
		return NULL;

	pb = kmalloc(sizeof(struct pl2303_buf), GFP_KERNEL);
	if (pb == NULL)
		return NULL;

	pb->buf_buf = kmalloc(size, GFP_KERNEL);
	if (pb->buf_buf == NULL) {
		kfree(pb);
		return NULL;
	}

	pb->buf_size = size;
	pb->buf_get = pb->buf_put = pb->buf_buf;

	return pb;
}

/*
 * pl2303_buf_free
 *
 * Free the buffer and all associated memory.
 */
static void pl2303_buf_free(struct pl2303_buf *pb)
{
	if (pb) {
		kfree(pb->buf_buf);
		kfree(pb);
	}
}

/*
 * pl2303_buf_clear
 *
 * Clear out all data in the circular buffer.
 */
static void pl2303_buf_clear(struct pl2303_buf *pb)
{
	if (pb != NULL)
		pb->buf_get = pb->buf_put;
		/* equivalent to a get of all data available */
}

/*
 * pl2303_buf_data_avail
 *
 * Return the number of bytes of data available in the circular
 * buffer.
 */
static unsigned int pl2303_buf_data_avail(struct pl2303_buf *pb)
{
	if (pb == NULL)
		return 0;

	return (pb->buf_size + pb->buf_put - pb->buf_get) % pb->buf_size;
}

/*
 * pl2303_buf_space_avail
 *
 * Return the number of bytes of space available in the circular
 * buffer.
 */
static unsigned int pl2303_buf_space_avail(struct pl2303_buf *pb)
{
	if (pb == NULL)
		return 0;

	return (pb->buf_size + pb->buf_get - pb->buf_put - 1) % pb->buf_size;
}

/*
 * pl2303_buf_put
 *
 * Copy data data from a user buffer and put it into the circular buffer.
 * Restrict to the amount of space available.
 *
 * Return the number of bytes copied.
 */
static unsigned int pl2303_buf_put(struct pl2303_buf *pb, const char *buf,
				   unsigned int count)
{
	unsigned int len;

	if (pb == NULL)
		return 0;

	len  = pl2303_buf_space_avail(pb);
	if (count > len)
		count = len;

	if (count == 0)
		return 0;

	len = pb->buf_buf + pb->buf_size - pb->buf_put;
	if (count > len) {
		memcpy(pb->buf_put, buf, len);
		memcpy(pb->buf_buf, buf+len, count - len);
		pb->buf_put = pb->buf_buf + count - len;
	} else {
		memcpy(pb->buf_put, buf, count);
		if (count < len)
			pb->buf_put += count;
		else /* count == len */
			pb->buf_put = pb->buf_buf;
	}

	return count;
}

/*
 * pl2303_buf_get
 *
 * Get data from the circular buffer and copy to the given buffer.
 * Restrict to the amount of data available.
 *
 * Return the number of bytes copied.
 */
static unsigned int pl2303_buf_get(struct pl2303_buf *pb, char *buf,
				   unsigned int count)
{
	unsigned int len;

	if (pb == NULL)
		return 0;

	len = pl2303_buf_data_avail(pb);
	if (count > len)
		count = len;

	if (count == 0)
		return 0;

	len = pb->buf_buf + pb->buf_size - pb->buf_get;
	if (count > len) {
		memcpy(buf, pb->buf_get, len);
		memcpy(buf+len, pb->buf_buf, count - len);
		pb->buf_get = pb->buf_buf + count - len;
	} else {
		memcpy(buf, pb->buf_get, count);
		if (count < len)
			pb->buf_get += count;
		else /* count == len */
			pb->buf_get = pb->buf_buf;
	}

	return count;
}

static int pl2303_vendor_read(__u16 value, __u16 index,
		struct usb_serial *serial, unsigned char *buf)
{
@@ -372,11 +201,6 @@ static int pl2303_startup(struct usb_serial *serial)
		if (!priv)
			goto cleanup;
		spin_lock_init(&priv->lock);
		priv->buf = pl2303_buf_alloc(PL2303_BUF_SIZE);
		if (priv->buf == NULL) {
			kfree(priv);
			goto cleanup;
		}
		init_waitqueue_head(&priv->delta_msr_wait);
		priv->type = type;
		usb_set_serial_port_data(serial->port[i], priv);
@@ -404,7 +228,6 @@ static int pl2303_startup(struct usb_serial *serial)
	kfree(buf);
	for (--i; i >= 0; --i) {
		priv = usb_get_serial_port_data(serial->port[i]);
		pl2303_buf_free(priv->buf);
		kfree(priv);
		usb_set_serial_port_data(serial->port[i], NULL);
	}
@@ -422,102 +245,6 @@ static int set_control_lines(struct usb_device *dev, u8 value)
	return retval;
}

static void pl2303_send(struct usb_serial_port *port)
{
	int count, result;
	struct pl2303_private *priv = usb_get_serial_port_data(port);
	unsigned long flags;

	dbg("%s - port %d", __func__, port->number);

	spin_lock_irqsave(&priv->lock, flags);

	if (priv->write_urb_in_use) {
		spin_unlock_irqrestore(&priv->lock, flags);
		return;
	}

	count = pl2303_buf_get(priv->buf, port->write_urb->transfer_buffer,
			       port->bulk_out_size);

	if (count == 0) {
		spin_unlock_irqrestore(&priv->lock, flags);
		return;
	}

	priv->write_urb_in_use = 1;

	spin_unlock_irqrestore(&priv->lock, flags);

	usb_serial_debug_data(debug, &port->dev, __func__, count,
			      port->write_urb->transfer_buffer);

	port->write_urb->transfer_buffer_length = count;
	result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
	if (result) {
		dev_err(&port->dev, "%s - failed submitting write urb,"
			" error %d\n", __func__, result);
		priv->write_urb_in_use = 0;
		/* TODO: reschedule pl2303_send */
	}

	usb_serial_port_softint(port);
}

static int pl2303_write(struct tty_struct *tty, struct usb_serial_port *port,
				const unsigned char *buf, int count)
{
	struct pl2303_private *priv = usb_get_serial_port_data(port);
	unsigned long flags;

	dbg("%s - port %d, %d bytes", __func__, port->number, count);

	if (!count)
		return count;

	spin_lock_irqsave(&priv->lock, flags);
	count = pl2303_buf_put(priv->buf, buf, count);
	spin_unlock_irqrestore(&priv->lock, flags);

	pl2303_send(port);

	return count;
}

static int pl2303_write_room(struct tty_struct *tty)
{
	struct usb_serial_port *port = tty->driver_data;
	struct pl2303_private *priv = usb_get_serial_port_data(port);
	int room = 0;
	unsigned long flags;

	dbg("%s - port %d", __func__, port->number);

	spin_lock_irqsave(&priv->lock, flags);
	room = pl2303_buf_space_avail(priv->buf);
	spin_unlock_irqrestore(&priv->lock, flags);

	dbg("%s - returns %d", __func__, room);
	return room;
}

static int pl2303_chars_in_buffer(struct tty_struct *tty)
{
	struct usb_serial_port *port = tty->driver_data;
	struct pl2303_private *priv = usb_get_serial_port_data(port);
	int chars = 0;
	unsigned long flags;

	dbg("%s - port %d", __func__, port->number);

	spin_lock_irqsave(&priv->lock, flags);
	chars = pl2303_buf_data_avail(priv->buf);
	spin_unlock_irqrestore(&priv->lock, flags);

	dbg("%s - returns %d", __func__, chars);
	return chars;
}

static void pl2303_set_termios(struct tty_struct *tty,
		struct usb_serial_port *port, struct ktermios *old_termios)
{
@@ -729,15 +456,14 @@ static void pl2303_dtr_rts(struct usb_serial_port *port, int on)

static void pl2303_close(struct usb_serial_port *port)
{
	struct pl2303_private *priv = usb_get_serial_port_data(port);
	unsigned long flags;

	dbg("%s - port %d", __func__, port->number);

	spin_lock_irqsave(&priv->lock, flags);
	spin_lock_irqsave(&port->lock, flags);
	/* clear out any remaining data in the buffer */
	pl2303_buf_clear(priv->buf);
	spin_unlock_irqrestore(&priv->lock, flags);
	kfifo_reset_out(&port->write_fifo);
	spin_unlock_irqrestore(&port->lock, flags);

	/* shutdown our urbs */
	dbg("%s - shutting down urbs", __func__);
@@ -951,12 +677,9 @@ static void pl2303_release(struct usb_serial *serial)

	for (i = 0; i < serial->num_ports; ++i) {
		priv = usb_get_serial_port_data(serial->port[i]);
		if (priv) {
			pl2303_buf_free(priv->buf);
		kfree(priv);
	}
}
}

static void pl2303_update_line_status(struct usb_serial_port *port,
				      unsigned char *data,
@@ -1086,47 +809,6 @@ static void pl2303_process_read_urb(struct urb *urb)
	tty_kref_put(tty);
}

static void pl2303_write_bulk_callback(struct urb *urb)
{
	struct usb_serial_port *port =  urb->context;
	struct pl2303_private *priv = usb_get_serial_port_data(port);
	int result;
	int status = urb->status;

	dbg("%s - port %d", __func__, port->number);

	switch (status) {
	case 0:
		/* success */
		break;
	case -ECONNRESET:
	case -ENOENT:
	case -ESHUTDOWN:
		/* this urb is terminated, clean up */
		dbg("%s - urb shutting down with status: %d", __func__,
		    status);
		priv->write_urb_in_use = 0;
		return;
	default:
		/* error in the urb, so we have to resubmit it */
		dbg("%s - Overflow in write", __func__);
		dbg("%s - nonzero write bulk status received: %d", __func__,
		    status);
		port->write_urb->transfer_buffer_length = 1;
		result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
		if (result)
			dev_err(&urb->dev->dev, "%s - failed resubmitting write"
				" urb, error %d\n", __func__, result);
		else
			return;
	}

	priv->write_urb_in_use = 0;

	/* send any buffered data */
	pl2303_send(port);
}

/* All of the device info needed for the PL2303 SIO serial converter */
static struct usb_serial_driver pl2303_device = {
	.driver = {
@@ -1142,7 +824,6 @@ static struct usb_serial_driver pl2303_device = {
	.close =		pl2303_close,
	.dtr_rts = 		pl2303_dtr_rts,
	.carrier_raised =	pl2303_carrier_raised,
	.write =		pl2303_write,
	.ioctl =		pl2303_ioctl,
	.break_ctl =		pl2303_break_ctl,
	.set_termios =		pl2303_set_termios,
@@ -1150,9 +831,6 @@ static struct usb_serial_driver pl2303_device = {
	.tiocmset =		pl2303_tiocmset,
	.process_read_urb =	pl2303_process_read_urb,
	.read_int_callback =	pl2303_read_int_callback,
	.write_bulk_callback =	pl2303_write_bulk_callback,
	.write_room =		pl2303_write_room,
	.chars_in_buffer =	pl2303_chars_in_buffer,
	.attach =		pl2303_startup,
	.release =		pl2303_release,
};