drivers/net/wimax/i2400m/usb-tx.c - kernel/bruno - Git at Google

 /*
  * Intel Wireless WiMAX Connection 2400m
  * USB specific TX handling
  *
  *
  * Copyright (C) 2007-2008 Intel Corporation. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  *   * Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  *   * Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in
  *     the documentation and/or other materials provided with the
  *     distribution.
  *   * Neither the name of Intel Corporation nor the names of its
  *     contributors may be used to endorse or promote products derived
  *     from this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  *
  * Intel Corporation <linux-wimax@intel.com>
  * Yanir Lubetkin <yanirx.lubetkin@intel.com>
  *  - Initial implementation
  * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
  *  - Split transport/device specific
  *
  *
  * Takes the TX messages in the i2400m's driver TX FIFO and sends them
  * to the device until there are no more.
  *
  * If we fail sending the message, we just drop it. There isn't much
  * we can do at this point. We could also retry, but the USB stack has
  * already retried and still failed, so there is not much of a
  * point. As well, most of the traffic is network, which has recovery
  * methods for dropped packets.
  *
  * For sending we just obtain a FIFO buffer to send, send it to the
  * USB bulk out, tell the TX FIFO code we have sent it; query for
  * another one, etc... until done.
  *
  * We use a thread so we can call usb_autopm_enable() and
  * usb_autopm_disable() for each transaction; this way when the device
  * goes idle, it will suspend. It also has less overhead than a
  * dedicated workqueue, as it is being used for a single task.
  *
  * ROADMAP
  *
  * i2400mu_tx_setup()
  * i2400mu_tx_release()
  *
  * i2400mu_bus_tx_kick()	- Called by the tx.c code when there
  *                                is new data in the FIFO.
  * i2400mu_txd()
  *   i2400m_tx_msg_get()
  *   i2400m_tx_msg_sent()
  */
 #include "i2400m-usb.h"


 #define D_SUBMODULE tx
 #include "usb-debug-levels.h"


 /*
  * Get the next TX message in the TX FIFO and send it to the device
  *
  * Note that any iteration consumes a message to be sent, no matter if
  * it succeeds or fails (we have no real way to retry or complain).
  *
  * Return: 0 if ok, < 0 errno code on hard error.
  */
 static
 int i2400mu_tx(struct i2400mu *i2400mu, struct i2400m_msg_hdr *tx_msg,
 	       size_t tx_msg_size)
 {
 	int result = 0;
 	struct i2400m *i2400m = &i2400mu->i2400m;
 	struct device *dev = &i2400mu->usb_iface->dev;
 	int usb_pipe, sent_size, do_autopm;
 	struct usb_endpoint_descriptor *epd;

 	d_fnstart(4, dev, "(i2400mu %p)\n", i2400mu);
 	do_autopm = atomic_read(&i2400mu->do_autopm);
 	result = do_autopm ?
 		usb_autopm_get_interface(i2400mu->usb_iface) : 0;
 	if (result < 0) {
 		dev_err(dev, "TX: can't get autopm: %d\n", result);
 		do_autopm = 0;
 	}
 	epd = usb_get_epd(i2400mu->usb_iface, i2400mu->endpoint_cfg.bulk_out);
 	usb_pipe = usb_sndbulkpipe(i2400mu->usb_dev, epd->bEndpointAddress);
 retry:
 	result = usb_bulk_msg(i2400mu->usb_dev, usb_pipe,
 			      tx_msg, tx_msg_size, &sent_size, 200);
 	usb_mark_last_busy(i2400mu->usb_dev);
 	switch (result) {
 	case 0:
 		if (sent_size != tx_msg_size) {	/* Too short? drop it */
 			dev_err(dev, "TX: short write (%d B vs %zu "
 				"expected)\n", sent_size, tx_msg_size);
 			result = -EIO;
 		}
 		break;
 	case -EPIPE:
 		/*
 		 * Stall -- maybe the device is choking with our
 		 * requests. Clear it and give it some time. If they
 		 * happen to often, it might be another symptom, so we
 		 * reset.
 		 *
 		 * No error handling for usb_clear_halt(0; if it
 		 * works, the retry works; if it fails, this switch
 		 * does the error handling for us.
 		 */
 		if (edc_inc(&i2400mu->urb_edc,
 			    10 * EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME)) {
 			dev_err(dev, "BM-CMD: too many stalls in "
 				"URB; resetting device\n");
 			usb_queue_reset_device(i2400mu->usb_iface);
 			/* fallthrough */
 		} else {
 			usb_clear_halt(i2400mu->usb_dev, usb_pipe);
 			msleep(10);	/* give the device some time */
 			goto retry;
 		}
 	case -EINVAL:			/* while removing driver */
 	case -ENODEV:			/* dev disconnect ... */
 	case -ENOENT:			/* just ignore it */
 	case -ESHUTDOWN:		/* and exit */
 	case -ECONNRESET:
 		result = -ESHUTDOWN;
 		break;
 	default:			/* Some error? */
 		if (edc_inc(&i2400mu->urb_edc,
 			    EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME)) {
 			dev_err(dev, "TX: maximum errors in URB "
 				"exceeded; resetting device\n");
 			usb_queue_reset_device(i2400mu->usb_iface);
 		} else {
 			dev_err(dev, "TX: cannot send URB; retrying. "
 				"tx_msg @%zu %zu B [%d sent]: %d\n",
 				(void *) tx_msg - i2400m->tx_buf,
 				tx_msg_size, sent_size, result);
 			goto retry;
 		}
 	}
 	if (do_autopm)
 		usb_autopm_put_interface(i2400mu->usb_iface);
 	d_fnend(4, dev, "(i2400mu %p) = result\n", i2400mu);
 	return result;
 }


 /*
  * Get the next TX message in the TX FIFO and send it to the device
  *
  * Note we exit the loop if i2400mu_tx() fails; that function only
  * fails on hard error (failing to tx a buffer not being one of them,
  * see its doc).
  *
  * Return: 0
  */
 static
 int i2400mu_txd(void *_i2400mu)
 {
 	struct i2400mu *i2400mu = _i2400mu;
 	struct i2400m *i2400m = &i2400mu->i2400m;
 	struct device *dev = &i2400mu->usb_iface->dev;
 	struct i2400m_msg_hdr *tx_msg;
 	size_t tx_msg_size;
 	unsigned long flags;

 	d_fnstart(4, dev, "(i2400mu %p)\n", i2400mu);

 	spin_lock_irqsave(&i2400m->tx_lock, flags);
 	BUG_ON(i2400mu->tx_kthread != NULL);
 	i2400mu->tx_kthread = current;
 	spin_unlock_irqrestore(&i2400m->tx_lock, flags);

 	while (1) {
 		d_printf(2, dev, "TX: waiting for messages\n");
 		tx_msg = NULL;
 		wait_event_interruptible(
 			i2400mu->tx_wq,
 			(kthread_should_stop()	/* check this first! */
 			 || (tx_msg = i2400m_tx_msg_get(i2400m, &tx_msg_size)))
 			);
 		if (kthread_should_stop())
 			break;
 		WARN_ON(tx_msg == NULL);	/* should not happen...*/
 		d_printf(2, dev, "TX: submitting %zu bytes\n", tx_msg_size);
 		d_dump(5, dev, tx_msg, tx_msg_size);
 		/* Yeah, we ignore errors ... not much we can do */
 		i2400mu_tx(i2400mu, tx_msg, tx_msg_size);
 		i2400m_tx_msg_sent(i2400m);	/* ack it, advance the FIFO */
 	}

 	spin_lock_irqsave(&i2400m->tx_lock, flags);
 	i2400mu->tx_kthread = NULL;
 	spin_unlock_irqrestore(&i2400m->tx_lock, flags);

 	d_fnend(4, dev, "(i2400mu %p)\n", i2400mu);
 	return 0;
 }


 /*
  * i2400m TX engine notifies us that there is data in the FIFO ready
  * for TX
  *
  * If there is a URB in flight, don't do anything; when it finishes,
  * it will see there is data in the FIFO and send it. Else, just
  * submit a write.
  */
 void i2400mu_bus_tx_kick(struct i2400m *i2400m)
 {
 	struct i2400mu *i2400mu = container_of(i2400m, struct i2400mu, i2400m);
 	struct device *dev = &i2400mu->usb_iface->dev;

 	d_fnstart(3, dev, "(i2400m %p) = void\n", i2400m);
 	wake_up_all(&i2400mu->tx_wq);
 	d_fnend(3, dev, "(i2400m %p) = void\n", i2400m);
 }


 int i2400mu_tx_setup(struct i2400mu *i2400mu)
 {
 	int result = 0;
 	struct i2400m *i2400m = &i2400mu->i2400m;
 	struct device *dev = &i2400mu->usb_iface->dev;
 	struct wimax_dev *wimax_dev = &i2400m->wimax_dev;
 	struct task_struct *kthread;

 	kthread = kthread_run(i2400mu_txd, i2400mu, "%s-tx",
 			      wimax_dev->name);
 	/* the kthread function sets i2400mu->tx_thread */
 	if (IS_ERR(kthread)) {
 		result = PTR_ERR(kthread);
 		dev_err(dev, "TX: cannot start thread: %d\n", result);
 	}
 	return result;
 }

 void i2400mu_tx_release(struct i2400mu *i2400mu)
 {
 	unsigned long flags;
 	struct i2400m *i2400m = &i2400mu->i2400m;
 	struct device *dev = i2400m_dev(i2400m);
 	struct task_struct *kthread;

 	spin_lock_irqsave(&i2400m->tx_lock, flags);
 	kthread = i2400mu->tx_kthread;
 	i2400mu->tx_kthread = NULL;
 	spin_unlock_irqrestore(&i2400m->tx_lock, flags);
 	if (kthread)
 		kthread_stop(kthread);
 	else
 		d_printf(1, dev, "TX: kthread had already exited\n");
 }
	/*
	* Intel Wireless WiMAX Connection 2400m
	* USB specific TX handling
	*
	*
	* Copyright (C) 2007-2008 Intel Corporation. All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	*
	* * Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* * Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in
	* the documentation and/or other materials provided with the
	* distribution.
	* * Neither the name of Intel Corporation nor the names of its
	* contributors may be used to endorse or promote products derived
	* from this software without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*
	*
	* Intel Corporation <linux-wimax@intel.com>
	* Yanir Lubetkin <yanirx.lubetkin@intel.com>
	* - Initial implementation
	* Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
	* - Split transport/device specific
	*
	*
	* Takes the TX messages in the i2400m's driver TX FIFO and sends them
	* to the device until there are no more.
	*
	* If we fail sending the message, we just drop it. There isn't much
	* we can do at this point. We could also retry, but the USB stack has
	* already retried and still failed, so there is not much of a
	* point. As well, most of the traffic is network, which has recovery
	* methods for dropped packets.
	*
	* For sending we just obtain a FIFO buffer to send, send it to the
	* USB bulk out, tell the TX FIFO code we have sent it; query for
	* another one, etc... until done.
	*
	* We use a thread so we can call usb_autopm_enable() and
	* usb_autopm_disable() for each transaction; this way when the device
	* goes idle, it will suspend. It also has less overhead than a
	* dedicated workqueue, as it is being used for a single task.
	*
	* ROADMAP
	*
	* i2400mu_tx_setup()
	* i2400mu_tx_release()
	*
	* i2400mu_bus_tx_kick() - Called by the tx.c code when there
	* is new data in the FIFO.
	* i2400mu_txd()
	* i2400m_tx_msg_get()
	* i2400m_tx_msg_sent()
	*/
	#include "i2400m-usb.h"


	#define D_SUBMODULE tx
	#include "usb-debug-levels.h"


	/*
	* Get the next TX message in the TX FIFO and send it to the device
	*
	* Note that any iteration consumes a message to be sent, no matter if
	* it succeeds or fails (we have no real way to retry or complain).
	*
	* Return: 0 if ok, < 0 errno code on hard error.
	*/
	static
	int i2400mu_tx(struct i2400mu i2400mu, struct i2400m_msg_hdr tx_msg,
	size_t tx_msg_size)
	{
	int result = 0;
	struct i2400m *i2400m = &i2400mu->i2400m;
	struct device *dev = &i2400mu->usb_iface->dev;
	int usb_pipe, sent_size, do_autopm;
	struct usb_endpoint_descriptor *epd;

	d_fnstart(4, dev, "(i2400mu %p)\n", i2400mu);
	do_autopm = atomic_read(&i2400mu->do_autopm);
	result = do_autopm ?
	usb_autopm_get_interface(i2400mu->usb_iface) : 0;
	if (result < 0) {
	dev_err(dev, "TX: can't get autopm: %d\n", result);
	do_autopm = 0;
	}
	epd = usb_get_epd(i2400mu->usb_iface, i2400mu->endpoint_cfg.bulk_out);
	usb_pipe = usb_sndbulkpipe(i2400mu->usb_dev, epd->bEndpointAddress);
	retry:
	result = usb_bulk_msg(i2400mu->usb_dev, usb_pipe,
	tx_msg, tx_msg_size, &sent_size, 200);
	usb_mark_last_busy(i2400mu->usb_dev);
	switch (result) {
	case 0:
	if (sent_size != tx_msg_size) { /* Too short? drop it */
	dev_err(dev, "TX: short write (%d B vs %zu "
	"expected)\n", sent_size, tx_msg_size);
	result = -EIO;
	}
	break;
	case -EPIPE:
	/*
	* Stall -- maybe the device is choking with our
	* requests. Clear it and give it some time. If they
	* happen to often, it might be another symptom, so we
	* reset.
	*
	* No error handling for usb_clear_halt(0; if it
	* works, the retry works; if it fails, this switch
	* does the error handling for us.
	*/
	if (edc_inc(&i2400mu->urb_edc,
	10 * EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME)) {
	dev_err(dev, "BM-CMD: too many stalls in "
	"URB; resetting device\n");
	usb_queue_reset_device(i2400mu->usb_iface);
	/* fallthrough */
	} else {
	usb_clear_halt(i2400mu->usb_dev, usb_pipe);
	msleep(10); /* give the device some time */
	goto retry;
	}
	case -EINVAL: /* while removing driver */
	case -ENODEV: /* dev disconnect ... */
	case -ENOENT: /* just ignore it */
	case -ESHUTDOWN: /* and exit */
	case -ECONNRESET:
	result = -ESHUTDOWN;
	break;
	default: /* Some error? */
	if (edc_inc(&i2400mu->urb_edc,
	EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME)) {
	dev_err(dev, "TX: maximum errors in URB "
	"exceeded; resetting device\n");
	usb_queue_reset_device(i2400mu->usb_iface);
	} else {
	dev_err(dev, "TX: cannot send URB; retrying. "
	"tx_msg @%zu %zu B [%d sent]: %d\n",
	(void *) tx_msg - i2400m->tx_buf,
	tx_msg_size, sent_size, result);
	goto retry;
	}
	}
	if (do_autopm)
	usb_autopm_put_interface(i2400mu->usb_iface);
	d_fnend(4, dev, "(i2400mu %p) = result\n", i2400mu);
	return result;
	}


	/*
	* Get the next TX message in the TX FIFO and send it to the device
	*
	* Note we exit the loop if i2400mu_tx() fails; that function only
	* fails on hard error (failing to tx a buffer not being one of them,
	* see its doc).
	*
	* Return: 0
	*/
	static
	int i2400mu_txd(void *_i2400mu)
	{
	struct i2400mu *i2400mu = _i2400mu;
	struct i2400m *i2400m = &i2400mu->i2400m;
	struct device *dev = &i2400mu->usb_iface->dev;
	struct i2400m_msg_hdr *tx_msg;
	size_t tx_msg_size;
	unsigned long flags;

	d_fnstart(4, dev, "(i2400mu %p)\n", i2400mu);

	spin_lock_irqsave(&i2400m->tx_lock, flags);
	BUG_ON(i2400mu->tx_kthread != NULL);
	i2400mu->tx_kthread = current;
	spin_unlock_irqrestore(&i2400m->tx_lock, flags);

	while (1) {
	d_printf(2, dev, "TX: waiting for messages\n");
	tx_msg = NULL;
	wait_event_interruptible(
	i2400mu->tx_wq,
	(kthread_should_stop() /* check this first! */
	\|\| (tx_msg = i2400m_tx_msg_get(i2400m, &tx_msg_size)))
	);
	if (kthread_should_stop())
	break;
	WARN_ON(tx_msg == NULL); /* should not happen...*/
	d_printf(2, dev, "TX: submitting %zu bytes\n", tx_msg_size);
	d_dump(5, dev, tx_msg, tx_msg_size);
	/* Yeah, we ignore errors ... not much we can do */
	i2400mu_tx(i2400mu, tx_msg, tx_msg_size);
	i2400m_tx_msg_sent(i2400m); /* ack it, advance the FIFO */
	}

	spin_lock_irqsave(&i2400m->tx_lock, flags);
	i2400mu->tx_kthread = NULL;
	spin_unlock_irqrestore(&i2400m->tx_lock, flags);

	d_fnend(4, dev, "(i2400mu %p)\n", i2400mu);
	return 0;
	}


	/*
	* i2400m TX engine notifies us that there is data in the FIFO ready
	* for TX
	*
	* If there is a URB in flight, don't do anything; when it finishes,
	* it will see there is data in the FIFO and send it. Else, just
	* submit a write.
	*/
	void i2400mu_bus_tx_kick(struct i2400m *i2400m)
	{
	struct i2400mu *i2400mu = container_of(i2400m, struct i2400mu, i2400m);
	struct device *dev = &i2400mu->usb_iface->dev;

	d_fnstart(3, dev, "(i2400m %p) = void\n", i2400m);
	wake_up_all(&i2400mu->tx_wq);
	d_fnend(3, dev, "(i2400m %p) = void\n", i2400m);
	}


	int i2400mu_tx_setup(struct i2400mu *i2400mu)
	{
	int result = 0;
	struct i2400m *i2400m = &i2400mu->i2400m;
	struct device *dev = &i2400mu->usb_iface->dev;
	struct wimax_dev *wimax_dev = &i2400m->wimax_dev;
	struct task_struct *kthread;

	kthread = kthread_run(i2400mu_txd, i2400mu, "%s-tx",
	wimax_dev->name);
	/* the kthread function sets i2400mu->tx_thread */
	if (IS_ERR(kthread)) {
	result = PTR_ERR(kthread);
	dev_err(dev, "TX: cannot start thread: %d\n", result);
	}
	return result;
	}

	void i2400mu_tx_release(struct i2400mu *i2400mu)
	{
	unsigned long flags;
	struct i2400m *i2400m = &i2400mu->i2400m;
	struct device *dev = i2400m_dev(i2400m);
	struct task_struct *kthread;

	spin_lock_irqsave(&i2400m->tx_lock, flags);
	kthread = i2400mu->tx_kthread;
	i2400mu->tx_kthread = NULL;
	spin_unlock_irqrestore(&i2400m->tx_lock, flags);
	if (kthread)
	kthread_stop(kthread);
	else
	d_printf(1, dev, "TX: kthread had already exited\n");
	}