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Commit d83b4053 authored by Johan Hovold's avatar Johan Hovold Committed by Greg Kroah-Hartman
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USB: serial: add support for multiple read urbs 



Add support for multiple read urbs to generic read implementation.

Use a static array of two read urbs for now which is enough to get a
50% throughput increase in one test setup.

Signed-off-by: default avatarJohan Hovold <jhovold@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent f5230a53

drivers/usb/serial/generic.c

+62 −21
Original line number Diff line number Diff line 
/*

 * USB Serial Converter Generic functions

 *

 * Copyright (C) 2010 Johan Hovold (jhovold@gmail.com)

 * Copyright (C) 2010 - 2011 Johan Hovold (jhovold@gmail.com)

 * Copyright (C) 1999 - 2002 Greg Kroah-Hartman (greg@kroah.com)

 *

 *	This program is free software; you can redistribute it and/or
@@ -132,7 +132,7 @@ int usb_serial_generic_open(struct tty_struct *tty, struct usb_serial_port *port 


	/* if we have a bulk endpoint, start reading from it */

	if (port->bulk_in_size)

		result = usb_serial_generic_submit_read_urb(port, GFP_KERNEL);

		result = usb_serial_generic_submit_read_urbs(port, GFP_KERNEL);



	return result;

}
@@ -157,8 +157,10 @@ static void generic_cleanup(struct usb_serial_port *port) 
			kfifo_reset_out(&port->write_fifo);

			spin_unlock_irqrestore(&port->lock, flags);

		}

		if (port->bulk_in_size)

			usb_kill_urb(port->read_urb);

		if (port->bulk_in_size) {

			for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i)

				usb_kill_urb(port->read_urbs[i]);

		}

	}

}
@@ -308,19 +310,52 @@ int usb_serial_generic_chars_in_buffer(struct tty_struct *tty) 
	return chars;

}



int usb_serial_generic_submit_read_urb(struct usb_serial_port *port,

static int usb_serial_generic_submit_read_urb(struct usb_serial_port *port,

						int index, gfp_t mem_flags)

{

	int res;



	if (!test_and_clear_bit(index, &port->read_urbs_free))

		return 0;



	dbg("%s - port %d, urb %d\n", __func__, port->number, index);



	res = usb_submit_urb(port->read_urbs[index], mem_flags);

	if (res) {

		if (res != -EPERM) {

			dev_err(&port->dev,

					"%s - usb_submit_urb failed: %d\n",

					__func__, res);

		}

		set_bit(index, &port->read_urbs_free);

		return res;

	}



	return 0;

}



int usb_serial_generic_submit_read_urbs(struct usb_serial_port *port,

					gfp_t mem_flags)

{

	int result;

	int res;

	int i;



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

	if (result && result != -EPERM) {

		dev_err(&port->dev, "%s - error submitting urb: %d\n",

							__func__, result);

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



	for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i) {

		res = usb_serial_generic_submit_read_urb(port, i, mem_flags);

		if (res)

			goto err;

	}

	return result;



	return 0;

err:

	for (; i >= 0; --i)

		usb_kill_urb(port->read_urbs[i]);



	return res;

}

EXPORT_SYMBOL_GPL(usb_serial_generic_submit_read_urb);

EXPORT_SYMBOL_GPL(usb_serial_generic_submit_read_urbs);



void usb_serial_generic_process_read_urb(struct urb *urb)

{
@@ -356,14 +391,19 @@ void usb_serial_generic_read_bulk_callback(struct urb *urb) 
{

	struct usb_serial_port *port = urb->context;

	unsigned char *data = urb->transfer_buffer;

	int status = urb->status;

	unsigned long flags;

	int i;



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

	for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i) {

		if (urb == port->read_urbs[i])

			break;

	}

	set_bit(i, &port->read_urbs_free);



	if (unlikely(status != 0)) {

		dbg("%s - nonzero read bulk status received: %d",

		    __func__, status);

	dbg("%s - port %d, urb %d, len %d\n", __func__, port->number, i,

							urb->actual_length);

	if (urb->status) {

		dbg("%s - non-zero urb status: %d\n", __func__, urb->status);

		return;

	}
@@ -376,7 +416,7 @@ void usb_serial_generic_read_bulk_callback(struct urb *urb) 
	port->throttled = port->throttle_req;

	if (!port->throttled) {

		spin_unlock_irqrestore(&port->lock, flags);

		usb_serial_generic_submit_read_urb(port, GFP_ATOMIC);

		usb_serial_generic_submit_read_urb(port, i, GFP_ATOMIC);

	} else

		spin_unlock_irqrestore(&port->lock, flags);

}
@@ -443,7 +483,7 @@ void usb_serial_generic_unthrottle(struct tty_struct *tty) 
	spin_unlock_irq(&port->lock);



	if (was_throttled)

		usb_serial_generic_submit_read_urb(port, GFP_KERNEL);

		usb_serial_generic_submit_read_urbs(port, GFP_KERNEL);

}

EXPORT_SYMBOL_GPL(usb_serial_generic_unthrottle);
@@ -509,8 +549,9 @@ int usb_serial_generic_resume(struct usb_serial *serial) 
		if (!test_bit(ASYNCB_INITIALIZED, &port->port.flags))

			continue;



		if (port->read_urb) {

			r = usb_submit_urb(port->read_urb, GFP_NOIO);

		if (port->bulk_in_size) {

			r = usb_serial_generic_submit_read_urbs(port,

								GFP_NOIO);

			if (r < 0)

				c++;

		}

drivers/usb/serial/usb-serial.c

+31 −19
Original line number Diff line number Diff line
@@ -562,7 +562,8 @@ static void kill_traffic(struct usb_serial_port *port) 
{

	int i;



	usb_kill_urb(port->read_urb);

	for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i)

		usb_kill_urb(port->read_urbs[i]);

	for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i)

		usb_kill_urb(port->write_urbs[i]);

	/*
@@ -594,15 +595,17 @@ static void port_release(struct device *dev) 
	kill_traffic(port);

	cancel_work_sync(&port->work);



	usb_free_urb(port->read_urb);

	usb_free_urb(port->interrupt_in_urb);

	usb_free_urb(port->interrupt_out_urb);

	for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i) {

		usb_free_urb(port->read_urbs[i]);

		kfree(port->bulk_in_buffers[i]);

	}

	for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i) {

		usb_free_urb(port->write_urbs[i]);

		kfree(port->bulk_out_buffers[i]);

	}

	kfifo_free(&port->write_fifo);

	kfree(port->bulk_in_buffer);

	kfree(port->interrupt_in_buffer);

	kfree(port->interrupt_out_buffer);

	kfree(port);
@@ -721,6 +724,7 @@ int usb_serial_probe(struct usb_interface *interface, 
	unsigned int minor;

	int buffer_size;

	int i;

	int j;

	int num_interrupt_in = 0;

	int num_interrupt_out = 0;

	int num_bulk_in = 0;
@@ -903,31 +907,39 @@ int usb_serial_probe(struct usb_interface *interface, 
	for (i = 0; i < num_bulk_in; ++i) {

		endpoint = bulk_in_endpoint[i];

		port = serial->port[i];

		port->read_urb = usb_alloc_urb(0, GFP_KERNEL);

		if (!port->read_urb) {

			dev_err(&interface->dev, "No free urbs available\n");

			goto probe_error;

		}

		buffer_size = max_t(int, serial->type->bulk_in_size,

				usb_endpoint_maxp(endpoint));

		port->bulk_in_size = buffer_size;

		port->bulk_in_endpointAddress = endpoint->bEndpointAddress;

		port->bulk_in_buffer = kmalloc(buffer_size, GFP_KERNEL);

		if (!port->bulk_in_buffer) {



		for (j = 0; j < ARRAY_SIZE(port->read_urbs); ++j) {

			set_bit(j, &port->read_urbs_free);

			port->read_urbs[j] = usb_alloc_urb(0, GFP_KERNEL);

			if (!port->read_urbs[j]) {

				dev_err(&interface->dev,

						"No free urbs available\n");

				goto probe_error;

			}

			port->bulk_in_buffers[j] = kmalloc(buffer_size,

								GFP_KERNEL);

			if (!port->bulk_in_buffers[j]) {

				dev_err(&interface->dev,

					"Couldn't allocate bulk_in_buffer\n");

				goto probe_error;

			}

		usb_fill_bulk_urb(port->read_urb, dev,

			usb_fill_bulk_urb(port->read_urbs[j], dev,

					usb_rcvbulkpipe(dev,

						endpoint->bEndpointAddress),

				port->bulk_in_buffer, buffer_size,

				serial->type->read_bulk_callback, port);

					port->bulk_in_buffers[j], buffer_size,

					serial->type->read_bulk_callback,

					port);

		}



	for (i = 0; i < num_bulk_out; ++i) {

		int j;

		port->read_urb = port->read_urbs[0];

		port->bulk_in_buffer = port->bulk_in_buffers[0];

	}



	for (i = 0; i < num_bulk_out; ++i) {

		endpoint = bulk_out_endpoint[i];

		port = serial->port[i];

		if (kfifo_alloc(&port->write_fifo, PAGE_SIZE, GFP_KERNEL))

include/linux/usb/serial.h

+8 −1
Original line number Diff line number Diff line
@@ -58,6 +58,9 @@ enum port_dev_state { 
 * @read_urb: pointer to the bulk in struct urb for this port.

 * @bulk_in_endpointAddress: endpoint address for the bulk in pipe for this

 *	port.

 * @bulk_in_buffers: pointers to the bulk in buffers for this port

 * @read_urbs: pointers to the bulk in urbs for this port

 * @read_urbs_free: status bitmap the for bulk in urbs

 * @bulk_out_buffer: pointer to the bulk out buffer for this port.

 * @bulk_out_size: the size of the bulk_out_buffer, in bytes.

 * @write_urb: pointer to the bulk out struct urb for this port.
@@ -98,6 +101,10 @@ struct usb_serial_port { 
	struct urb		*read_urb;

	__u8			bulk_in_endpointAddress;



	unsigned char		*bulk_in_buffers[2];

	struct urb		*read_urbs[2];

	unsigned long		read_urbs_free;



	unsigned char		*bulk_out_buffer;

	int			bulk_out_size;

	struct urb		*write_urb;
@@ -338,7 +345,7 @@ extern void usb_serial_generic_disconnect(struct usb_serial *serial); 
extern void usb_serial_generic_release(struct usb_serial *serial);

extern int usb_serial_generic_register(int debug);

extern void usb_serial_generic_deregister(void);

extern int usb_serial_generic_submit_read_urb(struct usb_serial_port *port,

extern int usb_serial_generic_submit_read_urbs(struct usb_serial_port *port,

						 gfp_t mem_flags);

extern void usb_serial_generic_process_read_urb(struct urb *urb);

extern int usb_serial_generic_prepare_write_buffer(struct usb_serial_port *port,