USB: serial: keyspan_pda: refactor write-room handling (79fe6826) · Commits · 戴 / test

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);

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