Commit 1abdeeb1 authored by Oliver Neukum's avatar Oliver Neukum Committed by Greg Kroah-Hartman
Browse files

USB: generic usb serial to new buffering scheme 



the generic driver also had its own buffering.

Signed-off-by: default avatarOliver Neukum <oneukum@suse.de_>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 39892da4

drivers/usb/serial/generic.c

+34 −35
Original line number Diff line number Diff line
@@ -281,45 +281,54 @@ int usb_serial_generic_chars_in_buffer (struct usb_serial_port *port) 
	return (chars);

}



/* Push data to tty layer and resubmit the bulk read URB */

static void flush_and_resubmit_read_urb (struct usb_serial_port *port)



static void resubmit_read_urb(struct usb_serial_port *port, gfp_t mem_flags)

{

	struct usb_serial *serial = port->serial;

	struct urb *urb = port->read_urb;

	struct tty_struct *tty = port->tty;

	struct usb_serial *serial = port->serial;

	int result;



	/* Push data to tty */

	if (tty && urb->actual_length) {

		tty_buffer_request_room(tty, urb->actual_length);

		tty_insert_flip_string(tty, urb->transfer_buffer, urb->actual_length);

	  	tty_flip_buffer_push(tty); /* is this allowed from an URB callback ? */

	}



	/* Continue reading from device */

	usb_fill_bulk_urb (port->read_urb, serial->dev,

	usb_fill_bulk_urb (urb, serial->dev,

			   usb_rcvbulkpipe (serial->dev,

				   	    port->bulk_in_endpointAddress),

			   port->read_urb->transfer_buffer,

			   port->read_urb->transfer_buffer_length,

			   urb->transfer_buffer,

			   urb->transfer_buffer_length,

			   ((serial->type->read_bulk_callback) ? 

			     serial->type->read_bulk_callback : 

			     usb_serial_generic_read_bulk_callback), port);

	result = usb_submit_urb(port->read_urb, GFP_ATOMIC);

	result = usb_submit_urb(urb, mem_flags);

	if (result)

		dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result);

}



/* Push data to tty layer and resubmit the bulk read URB */

static void flush_and_resubmit_read_urb (struct usb_serial_port *port)

{

	struct urb *urb = port->read_urb;

	struct tty_struct *tty = port->tty;

	int room;



	/* Push data to tty */

	if (tty && urb->actual_length) {

		room = tty_buffer_request_room(tty, urb->actual_length);

		if (room) {

			tty_insert_flip_string(tty, urb->transfer_buffer, room);

			tty_flip_buffer_push(tty); /* is this allowed from an URB callback ? */

		}

	}



	resubmit_read_urb(port, GFP_ATOMIC);

}



void usb_serial_generic_read_bulk_callback (struct urb *urb)

{

	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;

	unsigned char *data = urb->transfer_buffer;

	int is_throttled;

	unsigned long flags;



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



	if (urb->status) {

	if (unlikely(urb->status != 0)) {

		dbg("%s - nonzero read bulk status received: %d", __FUNCTION__, urb->status);

		return;

	}
@@ -327,21 +336,11 @@ void usb_serial_generic_read_bulk_callback (struct urb *urb) 
	usb_serial_debug_data(debug, &port->dev, __FUNCTION__, urb->actual_length, data);



	/* Throttle the device if requested by tty */

	if (urb->actual_length) {

		spin_lock_irqsave(&port->lock, flags);

		is_throttled = port->throttled = port->throttle_req;

		spin_unlock_irqrestore(&port->lock, flags);

		if (is_throttled) {

			/* Let the received data linger in the read URB;

			 * usb_serial_generic_unthrottle() will pick it

			 * up later. */

			dbg("%s - throttling device", __FUNCTION__);

			return;

		}

	}



	spin_lock(&port->lock);

	if (!(port->throttled = port->throttle_req))

		/* Handle data and continue reading from device */

		flush_and_resubmit_read_urb(port);

	spin_unlock(&port->lock);

}

EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback);
@@ -388,8 +387,8 @@ void usb_serial_generic_unthrottle (struct usb_serial_port *port) 
	spin_unlock_irqrestore(&port->lock, flags);



	if (was_throttled) {

		/* Handle pending data and resume reading from device */

		flush_and_resubmit_read_urb(port);

		/* Resume reading from device */

		resubmit_read_urb(port, GFP_KERNEL);

	}

}