drivers/net/wimax/i2400m/usb-fw.c - arm/linux - Git at Google

 /*
  * Intel Wireless WiMAX Connection 2400m
  * Firmware uploader's USB specifics
  *
  *
  * 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>
  * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
  *  - Initial implementation
  *
  * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
  *  - bus generic/specific split
  *
  * THE PROCEDURE
  *
  * See fw.c for the generic description of this procedure.
  *
  * This file implements only the USB specifics. It boils down to how
  * to send a command and waiting for an acknowledgement from the
  * device.
  *
  * This code (and process) is single threaded. It assumes it is the
  * only thread poking around (guaranteed by fw.c).
  *
  * COMMAND EXECUTION
  *
  * A write URB is posted with the buffer to the bulk output endpoint.
  *
  * ACK RECEPTION
  *
  * We just post a URB to the notification endpoint and wait for
  * data. We repeat until we get all the data we expect (as indicated
  * by the call from the bus generic code).
  *
  * The data is not read from the bulk in endpoint for boot mode.
  *
  * ROADMAP
  *
  * i2400mu_bus_bm_cmd_send
  *   i2400m_bm_cmd_prepare...
  *   i2400mu_tx_bulk_out
  *
  * i2400mu_bus_bm_wait_for_ack
  *   i2400m_notif_submit
  */
 #include <linux/usb.h>
 #include <linux/gfp.h>
 #include "i2400m-usb.h"


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


 /*
  * Synchronous write to the device
  *
  * Takes care of updating EDC counts and thus, handle device errors.
  */
 static
 ssize_t i2400mu_tx_bulk_out(struct i2400mu *i2400mu, void *buf, size_t buf_size)
 {
 	int result;
 	struct device *dev = &i2400mu->usb_iface->dev;
 	int len;
 	struct usb_endpoint_descriptor *epd;
 	int pipe, do_autopm = 1;

 	result = usb_autopm_get_interface(i2400mu->usb_iface);
 	if (result < 0) {
 		dev_err(dev, "BM-CMD: can't get autopm: %d\n", result);
 		do_autopm = 0;
 	}
 	epd = usb_get_epd(i2400mu->usb_iface, i2400mu->endpoint_cfg.bulk_out);
 	pipe = usb_sndbulkpipe(i2400mu->usb_dev, epd->bEndpointAddress);
 retry:
 	result = usb_bulk_msg(i2400mu->usb_dev, pipe, buf, buf_size, &len, 200);
 	switch (result) {
 	case 0:
 		if (len != buf_size) {
 			dev_err(dev, "BM-CMD: short write (%u B vs %zu "
 				"expected)\n", len, buf_size);
 			result = -EIO;
 			break;
 		}
 		result = len;
 		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, 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;
 	case -ETIMEDOUT:			/* bah... */
 		break;
 	default:				/* any other? */
 		if (edc_inc(&i2400mu->urb_edc,
 			    EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME)) {
 				dev_err(dev, "BM-CMD: maximum errors in "
 					"URB exceeded; resetting device\n");
 				usb_queue_reset_device(i2400mu->usb_iface);
 				result = -ENODEV;
 				break;
 		}
 		dev_err(dev, "BM-CMD: URB error %d, retrying\n",
 			result);
 		goto retry;
 	}
 	if (do_autopm)
 		usb_autopm_put_interface(i2400mu->usb_iface);
 	return result;
 }


 /*
  * Send a boot-mode command over the bulk-out pipe
  *
  * Command can be a raw command, which requires no preparation (and
  * which might not even be following the command format). Checks that
  * the right amount of data was transferred.
  *
  * To satisfy USB requirements (no onstack, vmalloc or in data segment
  * buffers), we copy the command to i2400m->bm_cmd_buf and send it from
  * there.
  *
  * @flags: pass thru from i2400m_bm_cmd()
  * @return: cmd_size if ok, < 0 errno code on error.
  */
 ssize_t i2400mu_bus_bm_cmd_send(struct i2400m *i2400m,
 				const struct i2400m_bootrom_header *_cmd,
 				size_t cmd_size, int flags)
 {
 	ssize_t result;
 	struct device *dev = i2400m_dev(i2400m);
 	struct i2400mu *i2400mu = container_of(i2400m, struct i2400mu, i2400m);
 	int opcode = _cmd == NULL ? -1 : i2400m_brh_get_opcode(_cmd);
 	struct i2400m_bootrom_header *cmd;
 	size_t cmd_size_a = ALIGN(cmd_size, 16);	/* USB restriction */

 	d_fnstart(8, dev, "(i2400m %p cmd %p size %zu)\n",
 		  i2400m, _cmd, cmd_size);
 	result = -E2BIG;
 	if (cmd_size > I2400M_BM_CMD_BUF_SIZE)
 		goto error_too_big;
 	if (_cmd != i2400m->bm_cmd_buf)
 		memmove(i2400m->bm_cmd_buf, _cmd, cmd_size);
 	cmd = i2400m->bm_cmd_buf;
 	if (cmd_size_a > cmd_size)			/* Zero pad space */
 		memset(i2400m->bm_cmd_buf + cmd_size, 0, cmd_size_a - cmd_size);
 	if ((flags & I2400M_BM_CMD_RAW) == 0) {
 		if (WARN_ON(i2400m_brh_get_response_required(cmd) == 0))
 			dev_warn(dev, "SW BUG: response_required == 0\n");
 		i2400m_bm_cmd_prepare(cmd);
 	}
 	result = i2400mu_tx_bulk_out(i2400mu, i2400m->bm_cmd_buf, cmd_size);
 	if (result < 0) {
 		dev_err(dev, "boot-mode cmd %d: cannot send: %zd\n",
 			opcode, result);
 		goto error_cmd_send;
 	}
 	if (result != cmd_size) {		/* all was transferred? */
 		dev_err(dev, "boot-mode cmd %d: incomplete transfer "
 			"(%zd vs %zu submitted)\n",  opcode, result, cmd_size);
 		result = -EIO;
 		goto error_cmd_size;
 	}
 error_cmd_size:
 error_cmd_send:
 error_too_big:
 	d_fnend(8, dev, "(i2400m %p cmd %p size %zu) = %zd\n",
 		i2400m, _cmd, cmd_size, result);
 	return result;
 }


 static
 void __i2400mu_bm_notif_cb(struct urb *urb)
 {
 	complete(urb->context);
 }


 /*
  * submit a read to the notification endpoint
  *
  * @i2400m: device descriptor
  * @urb: urb to use
  * @completion: completion variable to complete when done
  *
  * Data is always read to i2400m->bm_ack_buf
  */
 static
 int i2400mu_notif_submit(struct i2400mu *i2400mu, struct urb *urb,
 			 struct completion *completion)
 {
 	struct i2400m *i2400m = &i2400mu->i2400m;
 	struct usb_endpoint_descriptor *epd;
 	int pipe;

 	epd = usb_get_epd(i2400mu->usb_iface,
 			  i2400mu->endpoint_cfg.notification);
 	pipe = usb_rcvintpipe(i2400mu->usb_dev, epd->bEndpointAddress);
 	usb_fill_int_urb(urb, i2400mu->usb_dev, pipe,
 			 i2400m->bm_ack_buf, I2400M_BM_ACK_BUF_SIZE,
 			 __i2400mu_bm_notif_cb, completion,
 			 epd->bInterval);
 	return usb_submit_urb(urb, GFP_KERNEL);
 }


 /*
  * Read an ack from  the notification endpoint
  *
  * @i2400m:
  * @_ack: pointer to where to store the read data
  * @ack_size: how many bytes we should read
  *
  * Returns: < 0 errno code on error; otherwise, amount of received bytes.
  *
  * Submits a notification read, appends the read data to the given ack
  * buffer and then repeats (until @ack_size bytes have been
  * received).
  */
 ssize_t i2400mu_bus_bm_wait_for_ack(struct i2400m *i2400m,
 				    struct i2400m_bootrom_header *_ack,
 				    size_t ack_size)
 {
 	ssize_t result = -ENOMEM;
 	struct device *dev = i2400m_dev(i2400m);
 	struct i2400mu *i2400mu = container_of(i2400m, struct i2400mu, i2400m);
 	struct urb notif_urb;
 	void *ack = _ack;
 	size_t offset, len;
 	long val;
 	int do_autopm = 1;
 	DECLARE_COMPLETION_ONSTACK(notif_completion);

 	d_fnstart(8, dev, "(i2400m %p ack %p size %zu)\n",
 		  i2400m, ack, ack_size);
 	BUG_ON(_ack == i2400m->bm_ack_buf);
 	result = usb_autopm_get_interface(i2400mu->usb_iface);
 	if (result < 0) {
 		dev_err(dev, "BM-ACK: can't get autopm: %d\n", (int) result);
 		do_autopm = 0;
 	}
 	usb_init_urb(&notif_urb);	/* ready notifications */
 	usb_get_urb(&notif_urb);
 	offset = 0;
 	while (offset < ack_size) {
 		init_completion(&notif_completion);
 		result = i2400mu_notif_submit(i2400mu, &notif_urb,
 					      &notif_completion);
 		if (result < 0)
 			goto error_notif_urb_submit;
 		val = wait_for_completion_interruptible_timeout(
 			&notif_completion, HZ);
 		if (val == 0) {
 			result = -ETIMEDOUT;
 			usb_kill_urb(&notif_urb);	/* Timedout */
 			goto error_notif_wait;
 		}
 		if (val == -ERESTARTSYS) {
 			result = -EINTR;		/* Interrupted */
 			usb_kill_urb(&notif_urb);
 			goto error_notif_wait;
 		}
 		result = notif_urb.status;		/* How was the ack? */
 		switch (result) {
 		case 0:
 			break;
 		case -EINVAL:			/* while removing driver */
 		case -ENODEV:			/* dev disconnect ... */
 		case -ENOENT:			/* just ignore it */
 		case -ESHUTDOWN:		/* and exit */
 		case -ECONNRESET:
 			result = -ESHUTDOWN;
 			goto error_dev_gone;
 		default:				/* any other? */
 			usb_kill_urb(&notif_urb);	/* Timedout */
 			if (edc_inc(&i2400mu->urb_edc,
 				    EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME))
 				goto error_exceeded;
 			dev_err(dev, "BM-ACK: URB error %d, "
 				"retrying\n", notif_urb.status);
 			continue;	/* retry */
 		}
 		if (notif_urb.actual_length == 0) {
 			d_printf(6, dev, "ZLP received, retrying\n");
 			continue;
 		}
 		/* Got data, append it to the buffer */
 		len = min(ack_size - offset, (size_t) notif_urb.actual_length);
 		memcpy(ack + offset, i2400m->bm_ack_buf, len);
 		offset += len;
 	}
 	result = offset;
 error_notif_urb_submit:
 error_notif_wait:
 error_dev_gone:
 out:
 	if (do_autopm)
 		usb_autopm_put_interface(i2400mu->usb_iface);
 	d_fnend(8, dev, "(i2400m %p ack %p size %zu) = %ld\n",
 		i2400m, ack, ack_size, (long) result);
 	return result;

 error_exceeded:
 	dev_err(dev, "bm: maximum errors in notification URB exceeded; "
 		"resetting device\n");
 	usb_queue_reset_device(i2400mu->usb_iface);
 	goto out;
 }
	/*
	* Intel Wireless WiMAX Connection 2400m
	* Firmware uploader's USB specifics
	*
	*
	* 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>
	* Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
	* - Initial implementation
	*
	* Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
	* - bus generic/specific split
	*
	* THE PROCEDURE
	*
	* See fw.c for the generic description of this procedure.
	*
	* This file implements only the USB specifics. It boils down to how
	* to send a command and waiting for an acknowledgement from the
	* device.
	*
	* This code (and process) is single threaded. It assumes it is the
	* only thread poking around (guaranteed by fw.c).
	*
	* COMMAND EXECUTION
	*
	* A write URB is posted with the buffer to the bulk output endpoint.
	*
	* ACK RECEPTION
	*
	* We just post a URB to the notification endpoint and wait for
	* data. We repeat until we get all the data we expect (as indicated
	* by the call from the bus generic code).
	*
	* The data is not read from the bulk in endpoint for boot mode.
	*
	* ROADMAP
	*
	* i2400mu_bus_bm_cmd_send
	* i2400m_bm_cmd_prepare...
	* i2400mu_tx_bulk_out
	*
	* i2400mu_bus_bm_wait_for_ack
	* i2400m_notif_submit
	*/
	#include <linux/usb.h>
	#include <linux/gfp.h>
	#include "i2400m-usb.h"


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


	/*
	* Synchronous write to the device
	*
	* Takes care of updating EDC counts and thus, handle device errors.
	*/
	static
	ssize_t i2400mu_tx_bulk_out(struct i2400mu i2400mu, void buf, size_t buf_size)
	{
	int result;
	struct device *dev = &i2400mu->usb_iface->dev;
	int len;
	struct usb_endpoint_descriptor *epd;
	int pipe, do_autopm = 1;

	result = usb_autopm_get_interface(i2400mu->usb_iface);
	if (result < 0) {
	dev_err(dev, "BM-CMD: can't get autopm: %d\n", result);
	do_autopm = 0;
	}
	epd = usb_get_epd(i2400mu->usb_iface, i2400mu->endpoint_cfg.bulk_out);
	pipe = usb_sndbulkpipe(i2400mu->usb_dev, epd->bEndpointAddress);
	retry:
	result = usb_bulk_msg(i2400mu->usb_dev, pipe, buf, buf_size, &len, 200);
	switch (result) {
	case 0:
	if (len != buf_size) {
	dev_err(dev, "BM-CMD: short write (%u B vs %zu "
	"expected)\n", len, buf_size);
	result = -EIO;
	break;
	}
	result = len;
	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, 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;
	case -ETIMEDOUT: /* bah... */
	break;
	default: /* any other? */
	if (edc_inc(&i2400mu->urb_edc,
	EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME)) {
	dev_err(dev, "BM-CMD: maximum errors in "
	"URB exceeded; resetting device\n");
	usb_queue_reset_device(i2400mu->usb_iface);
	result = -ENODEV;
	break;
	}
	dev_err(dev, "BM-CMD: URB error %d, retrying\n",
	result);
	goto retry;
	}
	if (do_autopm)
	usb_autopm_put_interface(i2400mu->usb_iface);
	return result;
	}


	/*
	* Send a boot-mode command over the bulk-out pipe
	*
	* Command can be a raw command, which requires no preparation (and
	* which might not even be following the command format). Checks that
	* the right amount of data was transferred.
	*
	* To satisfy USB requirements (no onstack, vmalloc or in data segment
	* buffers), we copy the command to i2400m->bm_cmd_buf and send it from
	* there.
	*
	* @flags: pass thru from i2400m_bm_cmd()
	* @return: cmd_size if ok, < 0 errno code on error.
	*/
	ssize_t i2400mu_bus_bm_cmd_send(struct i2400m *i2400m,
	const struct i2400m_bootrom_header *_cmd,
	size_t cmd_size, int flags)
	{
	ssize_t result;
	struct device *dev = i2400m_dev(i2400m);
	struct i2400mu *i2400mu = container_of(i2400m, struct i2400mu, i2400m);
	int opcode = _cmd == NULL ? -1 : i2400m_brh_get_opcode(_cmd);
	struct i2400m_bootrom_header *cmd;
	size_t cmd_size_a = ALIGN(cmd_size, 16); /* USB restriction */

	d_fnstart(8, dev, "(i2400m %p cmd %p size %zu)\n",
	i2400m, _cmd, cmd_size);
	result = -E2BIG;
	if (cmd_size > I2400M_BM_CMD_BUF_SIZE)
	goto error_too_big;
	if (_cmd != i2400m->bm_cmd_buf)
	memmove(i2400m->bm_cmd_buf, _cmd, cmd_size);
	cmd = i2400m->bm_cmd_buf;
	if (cmd_size_a > cmd_size) /* Zero pad space */
	memset(i2400m->bm_cmd_buf + cmd_size, 0, cmd_size_a - cmd_size);
	if ((flags & I2400M_BM_CMD_RAW) == 0) {
	if (WARN_ON(i2400m_brh_get_response_required(cmd) == 0))
	dev_warn(dev, "SW BUG: response_required == 0\n");
	i2400m_bm_cmd_prepare(cmd);
	}
	result = i2400mu_tx_bulk_out(i2400mu, i2400m->bm_cmd_buf, cmd_size);
	if (result < 0) {
	dev_err(dev, "boot-mode cmd %d: cannot send: %zd\n",
	opcode, result);
	goto error_cmd_send;
	}
	if (result != cmd_size) { /* all was transferred? */
	dev_err(dev, "boot-mode cmd %d: incomplete transfer "
	"(%zd vs %zu submitted)\n", opcode, result, cmd_size);
	result = -EIO;
	goto error_cmd_size;
	}
	error_cmd_size:
	error_cmd_send:
	error_too_big:
	d_fnend(8, dev, "(i2400m %p cmd %p size %zu) = %zd\n",
	i2400m, _cmd, cmd_size, result);
	return result;
	}


	static
	void __i2400mu_bm_notif_cb(struct urb *urb)
	{
	complete(urb->context);
	}


	/*
	* submit a read to the notification endpoint
	*
	* @i2400m: device descriptor
	* @urb: urb to use
	* @completion: completion variable to complete when done
	*
	* Data is always read to i2400m->bm_ack_buf
	*/
	static
	int i2400mu_notif_submit(struct i2400mu i2400mu, struct urb urb,
	struct completion *completion)
	{
	struct i2400m *i2400m = &i2400mu->i2400m;
	struct usb_endpoint_descriptor *epd;
	int pipe;

	epd = usb_get_epd(i2400mu->usb_iface,
	i2400mu->endpoint_cfg.notification);
	pipe = usb_rcvintpipe(i2400mu->usb_dev, epd->bEndpointAddress);
	usb_fill_int_urb(urb, i2400mu->usb_dev, pipe,
	i2400m->bm_ack_buf, I2400M_BM_ACK_BUF_SIZE,
	__i2400mu_bm_notif_cb, completion,
	epd->bInterval);
	return usb_submit_urb(urb, GFP_KERNEL);
	}


	/*
	* Read an ack from the notification endpoint
	*
	* @i2400m:
	* @_ack: pointer to where to store the read data
	* @ack_size: how many bytes we should read
	*
	* Returns: < 0 errno code on error; otherwise, amount of received bytes.
	*
	* Submits a notification read, appends the read data to the given ack
	* buffer and then repeats (until @ack_size bytes have been
	* received).
	*/
	ssize_t i2400mu_bus_bm_wait_for_ack(struct i2400m *i2400m,
	struct i2400m_bootrom_header *_ack,
	size_t ack_size)
	{
	ssize_t result = -ENOMEM;
	struct device *dev = i2400m_dev(i2400m);
	struct i2400mu *i2400mu = container_of(i2400m, struct i2400mu, i2400m);
	struct urb notif_urb;
	void *ack = _ack;
	size_t offset, len;
	long val;
	int do_autopm = 1;
	DECLARE_COMPLETION_ONSTACK(notif_completion);

	d_fnstart(8, dev, "(i2400m %p ack %p size %zu)\n",
	i2400m, ack, ack_size);
	BUG_ON(_ack == i2400m->bm_ack_buf);
	result = usb_autopm_get_interface(i2400mu->usb_iface);
	if (result < 0) {
	dev_err(dev, "BM-ACK: can't get autopm: %d\n", (int) result);
	do_autopm = 0;
	}
	usb_init_urb(&notif_urb); /* ready notifications */
	usb_get_urb(&notif_urb);
	offset = 0;
	while (offset < ack_size) {
	init_completion(&notif_completion);
	result = i2400mu_notif_submit(i2400mu, &notif_urb,
	&notif_completion);
	if (result < 0)
	goto error_notif_urb_submit;
	val = wait_for_completion_interruptible_timeout(
	&notif_completion, HZ);
	if (val == 0) {
	result = -ETIMEDOUT;
	usb_kill_urb(&notif_urb); /* Timedout */
	goto error_notif_wait;
	}
	if (val == -ERESTARTSYS) {
	result = -EINTR; /* Interrupted */
	usb_kill_urb(&notif_urb);
	goto error_notif_wait;
	}
	result = notif_urb.status; /* How was the ack? */
	switch (result) {
	case 0:
	break;
	case -EINVAL: /* while removing driver */
	case -ENODEV: /* dev disconnect ... */
	case -ENOENT: /* just ignore it */
	case -ESHUTDOWN: /* and exit */
	case -ECONNRESET:
	result = -ESHUTDOWN;
	goto error_dev_gone;
	default: /* any other? */
	usb_kill_urb(&notif_urb); /* Timedout */
	if (edc_inc(&i2400mu->urb_edc,
	EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME))
	goto error_exceeded;
	dev_err(dev, "BM-ACK: URB error %d, "
	"retrying\n", notif_urb.status);
	continue; /* retry */
	}
	if (notif_urb.actual_length == 0) {
	d_printf(6, dev, "ZLP received, retrying\n");
	continue;
	}
	/* Got data, append it to the buffer */
	len = min(ack_size - offset, (size_t) notif_urb.actual_length);
	memcpy(ack + offset, i2400m->bm_ack_buf, len);
	offset += len;
	}
	result = offset;
	error_notif_urb_submit:
	error_notif_wait:
	error_dev_gone:
	out:
	if (do_autopm)
	usb_autopm_put_interface(i2400mu->usb_iface);
	d_fnend(8, dev, "(i2400m %p ack %p size %zu) = %ld\n",
	i2400m, ack, ack_size, (long) result);
	return result;

	error_exceeded:
	dev_err(dev, "bm: maximum errors in notification URB exceeded; "
	"resetting device\n");
	usb_queue_reset_device(i2400mu->usb_iface);
	goto out;
	}