1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * message.c - synchronous message handling
   4 *
   5 * Released under the GPLv2 only.
   6 */
   7
   8#include <linux/acpi.h>
   9#include <linux/pci.h>	/* for scatterlist macros */
  10#include <linux/usb.h>
  11#include <linux/module.h>
  12#include <linux/slab.h>
 
  13#include <linux/mm.h>
  14#include <linux/timer.h>
  15#include <linux/ctype.h>
  16#include <linux/nls.h>
  17#include <linux/device.h>
  18#include <linux/scatterlist.h>
  19#include <linux/usb/cdc.h>
  20#include <linux/usb/quirks.h>
  21#include <linux/usb/hcd.h>	/* for usbcore internals */
  22#include <linux/usb/of.h>
  23#include <asm/byteorder.h>
  24
  25#include "usb.h"
  26
  27static void cancel_async_set_config(struct usb_device *udev);
  28
  29struct api_context {
  30	struct completion	done;
  31	int			status;
  32};
  33
  34static void usb_api_blocking_completion(struct urb *urb)
  35{
  36	struct api_context *ctx = urb->context;
  37
  38	ctx->status = urb->status;
  39	complete(&ctx->done);
  40}
  41
  42
  43/*
  44 * Starts urb and waits for completion or timeout. Note that this call
  45 * is NOT interruptible. Many device driver i/o requests should be
  46 * interruptible and therefore these drivers should implement their
  47 * own interruptible routines.
  48 */
  49static int usb_start_wait_urb(struct urb *urb, int timeout, int *actual_length)
  50{
  51	struct api_context ctx;
  52	unsigned long expire;
  53	int retval;
  54
  55	init_completion(&ctx.done);
  56	urb->context = &ctx;
  57	urb->actual_length = 0;
  58	retval = usb_submit_urb(urb, GFP_NOIO);
  59	if (unlikely(retval))
  60		goto out;
  61
  62	expire = timeout ? msecs_to_jiffies(timeout) : MAX_SCHEDULE_TIMEOUT;
  63	if (!wait_for_completion_timeout(&ctx.done, expire)) {
  64		usb_kill_urb(urb);
  65		retval = (ctx.status == -ENOENT ? -ETIMEDOUT : ctx.status);
  66
  67		dev_dbg(&urb->dev->dev,
  68			"%s timed out on ep%d%s len=%u/%u\n",
  69			current->comm,
  70			usb_endpoint_num(&urb->ep->desc),
  71			usb_urb_dir_in(urb) ? "in" : "out",
  72			urb->actual_length,
  73			urb->transfer_buffer_length);
  74	} else
  75		retval = ctx.status;
  76out:
  77	if (actual_length)
  78		*actual_length = urb->actual_length;
  79
  80	usb_free_urb(urb);
  81	return retval;
  82}
  83
  84/*-------------------------------------------------------------------*/
  85/* returns status (negative) or length (positive) */
  86static int usb_internal_control_msg(struct usb_device *usb_dev,
  87				    unsigned int pipe,
  88				    struct usb_ctrlrequest *cmd,
  89				    void *data, int len, int timeout)
  90{
  91	struct urb *urb;
  92	int retv;
  93	int length;
  94
  95	urb = usb_alloc_urb(0, GFP_NOIO);
  96	if (!urb)
  97		return -ENOMEM;
  98
  99	usb_fill_control_urb(urb, usb_dev, pipe, (unsigned char *)cmd, data,
 100			     len, usb_api_blocking_completion, NULL);
 101
 102	retv = usb_start_wait_urb(urb, timeout, &length);
 103	if (retv < 0)
 104		return retv;
 105	else
 106		return length;
 107}
 108
 109/**
 110 * usb_control_msg - Builds a control urb, sends it off and waits for completion
 111 * @dev: pointer to the usb device to send the message to
 112 * @pipe: endpoint "pipe" to send the message to
 113 * @request: USB message request value
 114 * @requesttype: USB message request type value
 115 * @value: USB message value
 116 * @index: USB message index value
 117 * @data: pointer to the data to send
 118 * @size: length in bytes of the data to send
 119 * @timeout: time in msecs to wait for the message to complete before timing
 120 *	out (if 0 the wait is forever)
 121 *
 122 * Context: !in_interrupt ()
 123 *
 124 * This function sends a simple control message to a specified endpoint and
 125 * waits for the message to complete, or timeout.
 126 *
 127 * Don't use this function from within an interrupt context. If you need
 128 * an asynchronous message, or need to send a message from within interrupt
 129 * context, use usb_submit_urb(). If a thread in your driver uses this call,
 130 * make sure your disconnect() method can wait for it to complete. Since you
 131 * don't have a handle on the URB used, you can't cancel the request.
 132 *
 133 * Return: If successful, the number of bytes transferred. Otherwise, a negative
 134 * error number.
 
 
 
 
 135 */
 136int usb_control_msg(struct usb_device *dev, unsigned int pipe, __u8 request,
 137		    __u8 requesttype, __u16 value, __u16 index, void *data,
 138		    __u16 size, int timeout)
 139{
 140	struct usb_ctrlrequest *dr;
 141	int ret;
 142
 143	dr = kmalloc(sizeof(struct usb_ctrlrequest), GFP_NOIO);
 144	if (!dr)
 145		return -ENOMEM;
 146
 147	dr->bRequestType = requesttype;
 148	dr->bRequest = request;
 149	dr->wValue = cpu_to_le16(value);
 150	dr->wIndex = cpu_to_le16(index);
 151	dr->wLength = cpu_to_le16(size);
 152
 153	ret = usb_internal_control_msg(dev, pipe, dr, data, size, timeout);
 154
 155	/* Linger a bit, prior to the next control message. */
 156	if (dev->quirks & USB_QUIRK_DELAY_CTRL_MSG)
 157		msleep(200);
 158
 159	kfree(dr);
 160
 161	return ret;
 162}
 163EXPORT_SYMBOL_GPL(usb_control_msg);
 164
 165/**
 166 * usb_interrupt_msg - Builds an interrupt urb, sends it off and waits for completion
 167 * @usb_dev: pointer to the usb device to send the message to
 168 * @pipe: endpoint "pipe" to send the message to
 169 * @data: pointer to the data to send
 170 * @len: length in bytes of the data to send
 171 * @actual_length: pointer to a location to put the actual length transferred
 172 *	in bytes
 173 * @timeout: time in msecs to wait for the message to complete before
 174 *	timing out (if 0 the wait is forever)
 175 *
 176 * Context: !in_interrupt ()
 177 *
 178 * This function sends a simple interrupt message to a specified endpoint and
 179 * waits for the message to complete, or timeout.
 180 *
 181 * Don't use this function from within an interrupt context. If you need
 182 * an asynchronous message, or need to send a message from within interrupt
 183 * context, use usb_submit_urb() If a thread in your driver uses this call,
 184 * make sure your disconnect() method can wait for it to complete. Since you
 185 * don't have a handle on the URB used, you can't cancel the request.
 186 *
 187 * Return:
 188 * If successful, 0. Otherwise a negative error number. The number of actual
 189 * bytes transferred will be stored in the @actual_length parameter.
 190 */
 191int usb_interrupt_msg(struct usb_device *usb_dev, unsigned int pipe,
 192		      void *data, int len, int *actual_length, int timeout)
 193{
 194	return usb_bulk_msg(usb_dev, pipe, data, len, actual_length, timeout);
 195}
 196EXPORT_SYMBOL_GPL(usb_interrupt_msg);
 197
 198/**
 199 * usb_bulk_msg - Builds a bulk urb, sends it off and waits for completion
 200 * @usb_dev: pointer to the usb device to send the message to
 201 * @pipe: endpoint "pipe" to send the message to
 202 * @data: pointer to the data to send
 203 * @len: length in bytes of the data to send
 204 * @actual_length: pointer to a location to put the actual length transferred
 205 *	in bytes
 206 * @timeout: time in msecs to wait for the message to complete before
 207 *	timing out (if 0 the wait is forever)
 208 *
 209 * Context: !in_interrupt ()
 210 *
 211 * This function sends a simple bulk message to a specified endpoint
 212 * and waits for the message to complete, or timeout.
 213 *
 214 * Don't use this function from within an interrupt context. If you need
 215 * an asynchronous message, or need to send a message from within interrupt
 216 * context, use usb_submit_urb() If a thread in your driver uses this call,
 217 * make sure your disconnect() method can wait for it to complete. Since you
 218 * don't have a handle on the URB used, you can't cancel the request.
 
 
 
 
 219 *
 220 * Because there is no usb_interrupt_msg() and no USBDEVFS_INTERRUPT ioctl,
 221 * users are forced to abuse this routine by using it to submit URBs for
 222 * interrupt endpoints.  We will take the liberty of creating an interrupt URB
 223 * (with the default interval) if the target is an interrupt endpoint.
 224 *
 225 * Return:
 226 * If successful, 0. Otherwise a negative error number. The number of actual
 227 * bytes transferred will be stored in the @actual_length parameter.
 228 *
 229 */
 230int usb_bulk_msg(struct usb_device *usb_dev, unsigned int pipe,
 231		 void *data, int len, int *actual_length, int timeout)
 232{
 233	struct urb *urb;
 234	struct usb_host_endpoint *ep;
 235
 236	ep = usb_pipe_endpoint(usb_dev, pipe);
 237	if (!ep || len < 0)
 238		return -EINVAL;
 239
 240	urb = usb_alloc_urb(0, GFP_KERNEL);
 241	if (!urb)
 242		return -ENOMEM;
 243
 244	if ((ep->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
 245			USB_ENDPOINT_XFER_INT) {
 246		pipe = (pipe & ~(3 << 30)) | (PIPE_INTERRUPT << 30);
 247		usb_fill_int_urb(urb, usb_dev, pipe, data, len,
 248				usb_api_blocking_completion, NULL,
 249				ep->desc.bInterval);
 250	} else
 251		usb_fill_bulk_urb(urb, usb_dev, pipe, data, len,
 252				usb_api_blocking_completion, NULL);
 253
 254	return usb_start_wait_urb(urb, timeout, actual_length);
 255}
 256EXPORT_SYMBOL_GPL(usb_bulk_msg);
 257
 258/*-------------------------------------------------------------------*/
 259
 260static void sg_clean(struct usb_sg_request *io)
 261{
 262	if (io->urbs) {
 263		while (io->entries--)
 264			usb_free_urb(io->urbs[io->entries]);
 265		kfree(io->urbs);
 266		io->urbs = NULL;
 267	}
 268	io->dev = NULL;
 269}
 270
 271static void sg_complete(struct urb *urb)
 272{
 273	unsigned long flags;
 274	struct usb_sg_request *io = urb->context;
 275	int status = urb->status;
 276
 277	spin_lock_irqsave(&io->lock, flags);
 278
 279	/* In 2.5 we require hcds' endpoint queues not to progress after fault
 280	 * reports, until the completion callback (this!) returns.  That lets
 281	 * device driver code (like this routine) unlink queued urbs first,
 282	 * if it needs to, since the HC won't work on them at all.  So it's
 283	 * not possible for page N+1 to overwrite page N, and so on.
 284	 *
 285	 * That's only for "hard" faults; "soft" faults (unlinks) sometimes
 286	 * complete before the HCD can get requests away from hardware,
 287	 * though never during cleanup after a hard fault.
 288	 */
 289	if (io->status
 290			&& (io->status != -ECONNRESET
 291				|| status != -ECONNRESET)
 292			&& urb->actual_length) {
 293		dev_err(io->dev->bus->controller,
 294			"dev %s ep%d%s scatterlist error %d/%d\n",
 295			io->dev->devpath,
 296			usb_endpoint_num(&urb->ep->desc),
 297			usb_urb_dir_in(urb) ? "in" : "out",
 298			status, io->status);
 299		/* BUG (); */
 300	}
 301
 302	if (io->status == 0 && status && status != -ECONNRESET) {
 303		int i, found, retval;
 304
 305		io->status = status;
 306
 307		/* the previous urbs, and this one, completed already.
 308		 * unlink pending urbs so they won't rx/tx bad data.
 309		 * careful: unlink can sometimes be synchronous...
 310		 */
 311		spin_unlock_irqrestore(&io->lock, flags);
 312		for (i = 0, found = 0; i < io->entries; i++) {
 313			if (!io->urbs[i])
 314				continue;
 315			if (found) {
 316				usb_block_urb(io->urbs[i]);
 317				retval = usb_unlink_urb(io->urbs[i]);
 318				if (retval != -EINPROGRESS &&
 319				    retval != -ENODEV &&
 320				    retval != -EBUSY &&
 321				    retval != -EIDRM)
 322					dev_err(&io->dev->dev,
 323						"%s, unlink --> %d\n",
 324						__func__, retval);
 325			} else if (urb == io->urbs[i])
 326				found = 1;
 327		}
 328		spin_lock_irqsave(&io->lock, flags);
 329	}
 330
 331	/* on the last completion, signal usb_sg_wait() */
 332	io->bytes += urb->actual_length;
 333	io->count--;
 334	if (!io->count)
 335		complete(&io->complete);
 336
 337	spin_unlock_irqrestore(&io->lock, flags);
 338}
 339
 340
 341/**
 342 * usb_sg_init - initializes scatterlist-based bulk/interrupt I/O request
 343 * @io: request block being initialized.  until usb_sg_wait() returns,
 344 *	treat this as a pointer to an opaque block of memory,
 345 * @dev: the usb device that will send or receive the data
 346 * @pipe: endpoint "pipe" used to transfer the data
 347 * @period: polling rate for interrupt endpoints, in frames or
 348 * 	(for high speed endpoints) microframes; ignored for bulk
 349 * @sg: scatterlist entries
 350 * @nents: how many entries in the scatterlist
 351 * @length: how many bytes to send from the scatterlist, or zero to
 352 * 	send every byte identified in the list.
 353 * @mem_flags: SLAB_* flags affecting memory allocations in this call
 354 *
 355 * This initializes a scatter/gather request, allocating resources such as
 356 * I/O mappings and urb memory (except maybe memory used by USB controller
 357 * drivers).
 358 *
 359 * The request must be issued using usb_sg_wait(), which waits for the I/O to
 360 * complete (or to be canceled) and then cleans up all resources allocated by
 361 * usb_sg_init().
 362 *
 363 * The request may be canceled with usb_sg_cancel(), either before or after
 364 * usb_sg_wait() is called.
 365 *
 366 * Return: Zero for success, else a negative errno value.
 367 */
 368int usb_sg_init(struct usb_sg_request *io, struct usb_device *dev,
 369		unsigned pipe, unsigned	period, struct scatterlist *sg,
 370		int nents, size_t length, gfp_t mem_flags)
 371{
 372	int i;
 373	int urb_flags;
 374	int use_sg;
 375
 376	if (!io || !dev || !sg
 377			|| usb_pipecontrol(pipe)
 378			|| usb_pipeisoc(pipe)
 379			|| nents <= 0)
 380		return -EINVAL;
 381
 382	spin_lock_init(&io->lock);
 383	io->dev = dev;
 384	io->pipe = pipe;
 385
 386	if (dev->bus->sg_tablesize > 0) {
 387		use_sg = true;
 388		io->entries = 1;
 389	} else {
 390		use_sg = false;
 391		io->entries = nents;
 392	}
 393
 394	/* initialize all the urbs we'll use */
 395	io->urbs = kmalloc_array(io->entries, sizeof(*io->urbs), mem_flags);
 396	if (!io->urbs)
 397		goto nomem;
 398
 399	urb_flags = URB_NO_INTERRUPT;
 400	if (usb_pipein(pipe))
 401		urb_flags |= URB_SHORT_NOT_OK;
 402
 403	for_each_sg(sg, sg, io->entries, i) {
 404		struct urb *urb;
 405		unsigned len;
 406
 407		urb = usb_alloc_urb(0, mem_flags);
 408		if (!urb) {
 409			io->entries = i;
 410			goto nomem;
 411		}
 412		io->urbs[i] = urb;
 413
 414		urb->dev = NULL;
 415		urb->pipe = pipe;
 416		urb->interval = period;
 417		urb->transfer_flags = urb_flags;
 418		urb->complete = sg_complete;
 419		urb->context = io;
 420		urb->sg = sg;
 421
 422		if (use_sg) {
 423			/* There is no single transfer buffer */
 424			urb->transfer_buffer = NULL;
 425			urb->num_sgs = nents;
 426
 427			/* A length of zero means transfer the whole sg list */
 428			len = length;
 429			if (len == 0) {
 430				struct scatterlist	*sg2;
 431				int			j;
 432
 433				for_each_sg(sg, sg2, nents, j)
 434					len += sg2->length;
 435			}
 436		} else {
 437			/*
 438			 * Some systems can't use DMA; they use PIO instead.
 439			 * For their sakes, transfer_buffer is set whenever
 440			 * possible.
 441			 */
 442			if (!PageHighMem(sg_page(sg)))
 443				urb->transfer_buffer = sg_virt(sg);
 444			else
 445				urb->transfer_buffer = NULL;
 446
 447			len = sg->length;
 448			if (length) {
 449				len = min_t(size_t, len, length);
 450				length -= len;
 451				if (length == 0)
 452					io->entries = i + 1;
 453			}
 454		}
 455		urb->transfer_buffer_length = len;
 456	}
 457	io->urbs[--i]->transfer_flags &= ~URB_NO_INTERRUPT;
 458
 459	/* transaction state */
 460	io->count = io->entries;
 461	io->status = 0;
 462	io->bytes = 0;
 463	init_completion(&io->complete);
 464	return 0;
 465
 466nomem:
 467	sg_clean(io);
 468	return -ENOMEM;
 469}
 470EXPORT_SYMBOL_GPL(usb_sg_init);
 471
 472/**
 473 * usb_sg_wait - synchronously execute scatter/gather request
 474 * @io: request block handle, as initialized with usb_sg_init().
 475 * 	some fields become accessible when this call returns.
 476 * Context: !in_interrupt ()
 477 *
 478 * This function blocks until the specified I/O operation completes.  It
 479 * leverages the grouping of the related I/O requests to get good transfer
 480 * rates, by queueing the requests.  At higher speeds, such queuing can
 481 * significantly improve USB throughput.
 482 *
 483 * There are three kinds of completion for this function.
 484 *
 485 * (1) success, where io->status is zero.  The number of io->bytes
 486 *     transferred is as requested.
 487 * (2) error, where io->status is a negative errno value.  The number
 488 *     of io->bytes transferred before the error is usually less
 489 *     than requested, and can be nonzero.
 490 * (3) cancellation, a type of error with status -ECONNRESET that
 491 *     is initiated by usb_sg_cancel().
 492 *
 493 * When this function returns, all memory allocated through usb_sg_init() or
 494 * this call will have been freed.  The request block parameter may still be
 495 * passed to usb_sg_cancel(), or it may be freed.  It could also be
 496 * reinitialized and then reused.
 497 *
 498 * Data Transfer Rates:
 499 *
 500 * Bulk transfers are valid for full or high speed endpoints.
 501 * The best full speed data rate is 19 packets of 64 bytes each
 502 * per frame, or 1216 bytes per millisecond.
 503 * The best high speed data rate is 13 packets of 512 bytes each
 504 * per microframe, or 52 KBytes per millisecond.
 505 *
 506 * The reason to use interrupt transfers through this API would most likely
 507 * be to reserve high speed bandwidth, where up to 24 KBytes per millisecond
 508 * could be transferred.  That capability is less useful for low or full
 509 * speed interrupt endpoints, which allow at most one packet per millisecond,
 510 * of at most 8 or 64 bytes (respectively).
 511 *
 512 * It is not necessary to call this function to reserve bandwidth for devices
 513 * under an xHCI host controller, as the bandwidth is reserved when the
 514 * configuration or interface alt setting is selected.
 515 */
 516void usb_sg_wait(struct usb_sg_request *io)
 517{
 518	int i;
 519	int entries = io->entries;
 520
 521	/* queue the urbs.  */
 522	spin_lock_irq(&io->lock);
 523	i = 0;
 524	while (i < entries && !io->status) {
 525		int retval;
 526
 527		io->urbs[i]->dev = io->dev;
 528		spin_unlock_irq(&io->lock);
 529
 530		retval = usb_submit_urb(io->urbs[i], GFP_NOIO);
 531
 
 
 
 
 532		switch (retval) {
 533			/* maybe we retrying will recover */
 534		case -ENXIO:	/* hc didn't queue this one */
 535		case -EAGAIN:
 536		case -ENOMEM:
 537			retval = 0;
 538			yield();
 539			break;
 540
 541			/* no error? continue immediately.
 542			 *
 543			 * NOTE: to work better with UHCI (4K I/O buffer may
 544			 * need 3K of TDs) it may be good to limit how many
 545			 * URBs are queued at once; N milliseconds?
 546			 */
 547		case 0:
 548			++i;
 549			cpu_relax();
 550			break;
 551
 552			/* fail any uncompleted urbs */
 553		default:
 554			io->urbs[i]->status = retval;
 555			dev_dbg(&io->dev->dev, "%s, submit --> %d\n",
 556				__func__, retval);
 557			usb_sg_cancel(io);
 558		}
 559		spin_lock_irq(&io->lock);
 560		if (retval && (io->status == 0 || io->status == -ECONNRESET))
 561			io->status = retval;
 562	}
 563	io->count -= entries - i;
 564	if (io->count == 0)
 565		complete(&io->complete);
 566	spin_unlock_irq(&io->lock);
 567
 568	/* OK, yes, this could be packaged as non-blocking.
 569	 * So could the submit loop above ... but it's easier to
 570	 * solve neither problem than to solve both!
 571	 */
 572	wait_for_completion(&io->complete);
 573
 574	sg_clean(io);
 575}
 576EXPORT_SYMBOL_GPL(usb_sg_wait);
 577
 578/**
 579 * usb_sg_cancel - stop scatter/gather i/o issued by usb_sg_wait()
 580 * @io: request block, initialized with usb_sg_init()
 581 *
 582 * This stops a request after it has been started by usb_sg_wait().
 583 * It can also prevents one initialized by usb_sg_init() from starting,
 584 * so that call just frees resources allocated to the request.
 585 */
 586void usb_sg_cancel(struct usb_sg_request *io)
 587{
 588	unsigned long flags;
 589	int i, retval;
 590
 591	spin_lock_irqsave(&io->lock, flags);
 592	if (io->status || io->count == 0) {
 593		spin_unlock_irqrestore(&io->lock, flags);
 594		return;
 595	}
 596	/* shut everything down */
 597	io->status = -ECONNRESET;
 598	io->count++;		/* Keep the request alive until we're done */
 599	spin_unlock_irqrestore(&io->lock, flags);
 600
 601	for (i = io->entries - 1; i >= 0; --i) {
 602		usb_block_urb(io->urbs[i]);
 
 
 
 
 
 
 603
 604		retval = usb_unlink_urb(io->urbs[i]);
 605		if (retval != -EINPROGRESS
 606		    && retval != -ENODEV
 607		    && retval != -EBUSY
 608		    && retval != -EIDRM)
 609			dev_warn(&io->dev->dev, "%s, unlink --> %d\n",
 610				 __func__, retval);
 
 
 
 
 611	}
 612
 613	spin_lock_irqsave(&io->lock, flags);
 614	io->count--;
 615	if (!io->count)
 616		complete(&io->complete);
 617	spin_unlock_irqrestore(&io->lock, flags);
 618}
 619EXPORT_SYMBOL_GPL(usb_sg_cancel);
 620
 621/*-------------------------------------------------------------------*/
 622
 623/**
 624 * usb_get_descriptor - issues a generic GET_DESCRIPTOR request
 625 * @dev: the device whose descriptor is being retrieved
 626 * @type: the descriptor type (USB_DT_*)
 627 * @index: the number of the descriptor
 628 * @buf: where to put the descriptor
 629 * @size: how big is "buf"?
 630 * Context: !in_interrupt ()
 631 *
 632 * Gets a USB descriptor.  Convenience functions exist to simplify
 633 * getting some types of descriptors.  Use
 634 * usb_get_string() or usb_string() for USB_DT_STRING.
 635 * Device (USB_DT_DEVICE) and configuration descriptors (USB_DT_CONFIG)
 636 * are part of the device structure.
 637 * In addition to a number of USB-standard descriptors, some
 638 * devices also use class-specific or vendor-specific descriptors.
 639 *
 640 * This call is synchronous, and may not be used in an interrupt context.
 641 *
 642 * Return: The number of bytes received on success, or else the status code
 643 * returned by the underlying usb_control_msg() call.
 644 */
 645int usb_get_descriptor(struct usb_device *dev, unsigned char type,
 646		       unsigned char index, void *buf, int size)
 647{
 648	int i;
 649	int result;
 650
 651	memset(buf, 0, size);	/* Make sure we parse really received data */
 652
 653	for (i = 0; i < 3; ++i) {
 654		/* retry on length 0 or error; some devices are flakey */
 655		result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
 656				USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
 657				(type << 8) + index, 0, buf, size,
 658				USB_CTRL_GET_TIMEOUT);
 659		if (result <= 0 && result != -ETIMEDOUT)
 660			continue;
 661		if (result > 1 && ((u8 *)buf)[1] != type) {
 662			result = -ENODATA;
 663			continue;
 664		}
 665		break;
 666	}
 667	return result;
 668}
 669EXPORT_SYMBOL_GPL(usb_get_descriptor);
 670
 671/**
 672 * usb_get_string - gets a string descriptor
 673 * @dev: the device whose string descriptor is being retrieved
 674 * @langid: code for language chosen (from string descriptor zero)
 675 * @index: the number of the descriptor
 676 * @buf: where to put the string
 677 * @size: how big is "buf"?
 678 * Context: !in_interrupt ()
 679 *
 680 * Retrieves a string, encoded using UTF-16LE (Unicode, 16 bits per character,
 681 * in little-endian byte order).
 682 * The usb_string() function will often be a convenient way to turn
 683 * these strings into kernel-printable form.
 684 *
 685 * Strings may be referenced in device, configuration, interface, or other
 686 * descriptors, and could also be used in vendor-specific ways.
 687 *
 688 * This call is synchronous, and may not be used in an interrupt context.
 689 *
 690 * Return: The number of bytes received on success, or else the status code
 691 * returned by the underlying usb_control_msg() call.
 692 */
 693static int usb_get_string(struct usb_device *dev, unsigned short langid,
 694			  unsigned char index, void *buf, int size)
 695{
 696	int i;
 697	int result;
 698
 699	for (i = 0; i < 3; ++i) {
 700		/* retry on length 0 or stall; some devices are flakey */
 701		result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
 702			USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
 703			(USB_DT_STRING << 8) + index, langid, buf, size,
 704			USB_CTRL_GET_TIMEOUT);
 705		if (result == 0 || result == -EPIPE)
 706			continue;
 707		if (result > 1 && ((u8 *) buf)[1] != USB_DT_STRING) {
 708			result = -ENODATA;
 709			continue;
 710		}
 711		break;
 712	}
 713	return result;
 714}
 715
 716static void usb_try_string_workarounds(unsigned char *buf, int *length)
 717{
 718	int newlength, oldlength = *length;
 719
 720	for (newlength = 2; newlength + 1 < oldlength; newlength += 2)
 721		if (!isprint(buf[newlength]) || buf[newlength + 1])
 722			break;
 723
 724	if (newlength > 2) {
 725		buf[0] = newlength;
 726		*length = newlength;
 727	}
 728}
 729
 730static int usb_string_sub(struct usb_device *dev, unsigned int langid,
 731			  unsigned int index, unsigned char *buf)
 732{
 733	int rc;
 734
 735	/* Try to read the string descriptor by asking for the maximum
 736	 * possible number of bytes */
 737	if (dev->quirks & USB_QUIRK_STRING_FETCH_255)
 738		rc = -EIO;
 739	else
 740		rc = usb_get_string(dev, langid, index, buf, 255);
 741
 742	/* If that failed try to read the descriptor length, then
 743	 * ask for just that many bytes */
 744	if (rc < 2) {
 745		rc = usb_get_string(dev, langid, index, buf, 2);
 746		if (rc == 2)
 747			rc = usb_get_string(dev, langid, index, buf, buf[0]);
 748	}
 749
 750	if (rc >= 2) {
 751		if (!buf[0] && !buf[1])
 752			usb_try_string_workarounds(buf, &rc);
 753
 754		/* There might be extra junk at the end of the descriptor */
 755		if (buf[0] < rc)
 756			rc = buf[0];
 757
 758		rc = rc - (rc & 1); /* force a multiple of two */
 759	}
 760
 761	if (rc < 2)
 762		rc = (rc < 0 ? rc : -EINVAL);
 763
 764	return rc;
 765}
 766
 767static int usb_get_langid(struct usb_device *dev, unsigned char *tbuf)
 768{
 769	int err;
 770
 771	if (dev->have_langid)
 772		return 0;
 773
 774	if (dev->string_langid < 0)
 775		return -EPIPE;
 776
 777	err = usb_string_sub(dev, 0, 0, tbuf);
 778
 779	/* If the string was reported but is malformed, default to english
 780	 * (0x0409) */
 781	if (err == -ENODATA || (err > 0 && err < 4)) {
 782		dev->string_langid = 0x0409;
 783		dev->have_langid = 1;
 784		dev_err(&dev->dev,
 785			"language id specifier not provided by device, defaulting to English\n");
 
 
 786		return 0;
 787	}
 788
 789	/* In case of all other errors, we assume the device is not able to
 790	 * deal with strings at all. Set string_langid to -1 in order to
 791	 * prevent any string to be retrieved from the device */
 792	if (err < 0) {
 793		dev_info(&dev->dev, "string descriptor 0 read error: %d\n",
 794					err);
 795		dev->string_langid = -1;
 796		return -EPIPE;
 797	}
 798
 799	/* always use the first langid listed */
 800	dev->string_langid = tbuf[2] | (tbuf[3] << 8);
 801	dev->have_langid = 1;
 802	dev_dbg(&dev->dev, "default language 0x%04x\n",
 803				dev->string_langid);
 804	return 0;
 805}
 806
 807/**
 808 * usb_string - returns UTF-8 version of a string descriptor
 809 * @dev: the device whose string descriptor is being retrieved
 810 * @index: the number of the descriptor
 811 * @buf: where to put the string
 812 * @size: how big is "buf"?
 813 * Context: !in_interrupt ()
 814 *
 815 * This converts the UTF-16LE encoded strings returned by devices, from
 816 * usb_get_string_descriptor(), to null-terminated UTF-8 encoded ones
 817 * that are more usable in most kernel contexts.  Note that this function
 818 * chooses strings in the first language supported by the device.
 819 *
 820 * This call is synchronous, and may not be used in an interrupt context.
 821 *
 822 * Return: length of the string (>= 0) or usb_control_msg status (< 0).
 823 */
 824int usb_string(struct usb_device *dev, int index, char *buf, size_t size)
 825{
 826	unsigned char *tbuf;
 827	int err;
 828
 829	if (dev->state == USB_STATE_SUSPENDED)
 830		return -EHOSTUNREACH;
 831	if (size <= 0 || !buf)
 832		return -EINVAL;
 833	buf[0] = 0;
 834	if (index <= 0 || index >= 256)
 835		return -EINVAL;
 836	tbuf = kmalloc(256, GFP_NOIO);
 837	if (!tbuf)
 838		return -ENOMEM;
 839
 840	err = usb_get_langid(dev, tbuf);
 841	if (err < 0)
 842		goto errout;
 843
 844	err = usb_string_sub(dev, dev->string_langid, index, tbuf);
 845	if (err < 0)
 846		goto errout;
 847
 848	size--;		/* leave room for trailing NULL char in output buffer */
 849	err = utf16s_to_utf8s((wchar_t *) &tbuf[2], (err - 2) / 2,
 850			UTF16_LITTLE_ENDIAN, buf, size);
 851	buf[err] = 0;
 852
 853	if (tbuf[1] != USB_DT_STRING)
 854		dev_dbg(&dev->dev,
 855			"wrong descriptor type %02x for string %d (\"%s\")\n",
 856			tbuf[1], index, buf);
 857
 858 errout:
 859	kfree(tbuf);
 860	return err;
 861}
 862EXPORT_SYMBOL_GPL(usb_string);
 863
 864/* one UTF-8-encoded 16-bit character has at most three bytes */
 865#define MAX_USB_STRING_SIZE (127 * 3 + 1)
 866
 867/**
 868 * usb_cache_string - read a string descriptor and cache it for later use
 869 * @udev: the device whose string descriptor is being read
 870 * @index: the descriptor index
 871 *
 872 * Return: A pointer to a kmalloc'ed buffer containing the descriptor string,
 873 * or %NULL if the index is 0 or the string could not be read.
 874 */
 875char *usb_cache_string(struct usb_device *udev, int index)
 876{
 877	char *buf;
 878	char *smallbuf = NULL;
 879	int len;
 880
 881	if (index <= 0)
 882		return NULL;
 883
 884	buf = kmalloc(MAX_USB_STRING_SIZE, GFP_NOIO);
 885	if (buf) {
 886		len = usb_string(udev, index, buf, MAX_USB_STRING_SIZE);
 887		if (len > 0) {
 888			smallbuf = kmalloc(++len, GFP_NOIO);
 889			if (!smallbuf)
 890				return buf;
 891			memcpy(smallbuf, buf, len);
 892		}
 893		kfree(buf);
 894	}
 895	return smallbuf;
 896}
 897
 898/*
 899 * usb_get_device_descriptor - (re)reads the device descriptor (usbcore)
 900 * @dev: the device whose device descriptor is being updated
 901 * @size: how much of the descriptor to read
 902 * Context: !in_interrupt ()
 903 *
 904 * Updates the copy of the device descriptor stored in the device structure,
 905 * which dedicates space for this purpose.
 906 *
 907 * Not exported, only for use by the core.  If drivers really want to read
 908 * the device descriptor directly, they can call usb_get_descriptor() with
 909 * type = USB_DT_DEVICE and index = 0.
 910 *
 911 * This call is synchronous, and may not be used in an interrupt context.
 912 *
 913 * Return: The number of bytes received on success, or else the status code
 914 * returned by the underlying usb_control_msg() call.
 915 */
 916int usb_get_device_descriptor(struct usb_device *dev, unsigned int size)
 917{
 918	struct usb_device_descriptor *desc;
 919	int ret;
 920
 921	if (size > sizeof(*desc))
 922		return -EINVAL;
 923	desc = kmalloc(sizeof(*desc), GFP_NOIO);
 924	if (!desc)
 925		return -ENOMEM;
 926
 927	ret = usb_get_descriptor(dev, USB_DT_DEVICE, 0, desc, size);
 928	if (ret >= 0)
 929		memcpy(&dev->descriptor, desc, size);
 930	kfree(desc);
 931	return ret;
 932}
 933
 934/*
 935 * usb_set_isoch_delay - informs the device of the packet transmit delay
 936 * @dev: the device whose delay is to be informed
 937 * Context: !in_interrupt()
 938 *
 939 * Since this is an optional request, we don't bother if it fails.
 940 */
 941int usb_set_isoch_delay(struct usb_device *dev)
 942{
 943	/* skip hub devices */
 944	if (dev->descriptor.bDeviceClass == USB_CLASS_HUB)
 945		return 0;
 946
 947	/* skip non-SS/non-SSP devices */
 948	if (dev->speed < USB_SPEED_SUPER)
 949		return 0;
 950
 951	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
 952			USB_REQ_SET_ISOCH_DELAY,
 953			USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
 954			dev->hub_delay, 0, NULL, 0,
 955			USB_CTRL_SET_TIMEOUT);
 956}
 957
 958/**
 959 * usb_get_status - issues a GET_STATUS call
 960 * @dev: the device whose status is being checked
 961 * @recip: USB_RECIP_*; for device, interface, or endpoint
 962 * @type: USB_STATUS_TYPE_*; for standard or PTM status types
 963 * @target: zero (for device), else interface or endpoint number
 964 * @data: pointer to two bytes of bitmap data
 965 * Context: !in_interrupt ()
 966 *
 967 * Returns device, interface, or endpoint status.  Normally only of
 968 * interest to see if the device is self powered, or has enabled the
 969 * remote wakeup facility; or whether a bulk or interrupt endpoint
 970 * is halted ("stalled").
 971 *
 972 * Bits in these status bitmaps are set using the SET_FEATURE request,
 973 * and cleared using the CLEAR_FEATURE request.  The usb_clear_halt()
 974 * function should be used to clear halt ("stall") status.
 975 *
 976 * This call is synchronous, and may not be used in an interrupt context.
 977 *
 978 * Returns 0 and the status value in *@data (in host byte order) on success,
 979 * or else the status code from the underlying usb_control_msg() call.
 980 */
 981int usb_get_status(struct usb_device *dev, int recip, int type, int target,
 982		void *data)
 983{
 984	int ret;
 985	void *status;
 986	int length;
 987
 988	switch (type) {
 989	case USB_STATUS_TYPE_STANDARD:
 990		length = 2;
 991		break;
 992	case USB_STATUS_TYPE_PTM:
 993		if (recip != USB_RECIP_DEVICE)
 994			return -EINVAL;
 995
 996		length = 4;
 997		break;
 998	default:
 999		return -EINVAL;
1000	}
1001
1002	status =  kmalloc(length, GFP_KERNEL);
1003	if (!status)
1004		return -ENOMEM;
1005
1006	ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
1007		USB_REQ_GET_STATUS, USB_DIR_IN | recip, USB_STATUS_TYPE_STANDARD,
1008		target, status, length, USB_CTRL_GET_TIMEOUT);
1009
1010	switch (ret) {
1011	case 4:
1012		if (type != USB_STATUS_TYPE_PTM) {
1013			ret = -EIO;
1014			break;
1015		}
1016
1017		*(u32 *) data = le32_to_cpu(*(__le32 *) status);
1018		ret = 0;
1019		break;
1020	case 2:
1021		if (type != USB_STATUS_TYPE_STANDARD) {
1022			ret = -EIO;
1023			break;
1024		}
1025
1026		*(u16 *) data = le16_to_cpu(*(__le16 *) status);
1027		ret = 0;
1028		break;
1029	default:
1030		ret = -EIO;
1031	}
1032
 
1033	kfree(status);
1034	return ret;
1035}
1036EXPORT_SYMBOL_GPL(usb_get_status);
1037
1038/**
1039 * usb_clear_halt - tells device to clear endpoint halt/stall condition
1040 * @dev: device whose endpoint is halted
1041 * @pipe: endpoint "pipe" being cleared
1042 * Context: !in_interrupt ()
1043 *
1044 * This is used to clear halt conditions for bulk and interrupt endpoints,
1045 * as reported by URB completion status.  Endpoints that are halted are
1046 * sometimes referred to as being "stalled".  Such endpoints are unable
1047 * to transmit or receive data until the halt status is cleared.  Any URBs
1048 * queued for such an endpoint should normally be unlinked by the driver
1049 * before clearing the halt condition, as described in sections 5.7.5
1050 * and 5.8.5 of the USB 2.0 spec.
1051 *
1052 * Note that control and isochronous endpoints don't halt, although control
1053 * endpoints report "protocol stall" (for unsupported requests) using the
1054 * same status code used to report a true stall.
1055 *
1056 * This call is synchronous, and may not be used in an interrupt context.
1057 *
1058 * Return: Zero on success, or else the status code returned by the
1059 * underlying usb_control_msg() call.
1060 */
1061int usb_clear_halt(struct usb_device *dev, int pipe)
1062{
1063	int result;
1064	int endp = usb_pipeendpoint(pipe);
1065
1066	if (usb_pipein(pipe))
1067		endp |= USB_DIR_IN;
1068
1069	/* we don't care if it wasn't halted first. in fact some devices
1070	 * (like some ibmcam model 1 units) seem to expect hosts to make
1071	 * this request for iso endpoints, which can't halt!
1072	 */
1073	result = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
1074		USB_REQ_CLEAR_FEATURE, USB_RECIP_ENDPOINT,
1075		USB_ENDPOINT_HALT, endp, NULL, 0,
1076		USB_CTRL_SET_TIMEOUT);
1077
1078	/* don't un-halt or force to DATA0 except on success */
1079	if (result < 0)
1080		return result;
1081
1082	/* NOTE:  seems like Microsoft and Apple don't bother verifying
1083	 * the clear "took", so some devices could lock up if you check...
1084	 * such as the Hagiwara FlashGate DUAL.  So we won't bother.
1085	 *
1086	 * NOTE:  make sure the logic here doesn't diverge much from
1087	 * the copy in usb-storage, for as long as we need two copies.
1088	 */
1089
1090	usb_reset_endpoint(dev, endp);
1091
1092	return 0;
1093}
1094EXPORT_SYMBOL_GPL(usb_clear_halt);
1095
1096static int create_intf_ep_devs(struct usb_interface *intf)
1097{
1098	struct usb_device *udev = interface_to_usbdev(intf);
1099	struct usb_host_interface *alt = intf->cur_altsetting;
1100	int i;
1101
1102	if (intf->ep_devs_created || intf->unregistering)
1103		return 0;
1104
1105	for (i = 0; i < alt->desc.bNumEndpoints; ++i)
1106		(void) usb_create_ep_devs(&intf->dev, &alt->endpoint[i], udev);
1107	intf->ep_devs_created = 1;
1108	return 0;
1109}
1110
1111static void remove_intf_ep_devs(struct usb_interface *intf)
1112{
1113	struct usb_host_interface *alt = intf->cur_altsetting;
1114	int i;
1115
1116	if (!intf->ep_devs_created)
1117		return;
1118
1119	for (i = 0; i < alt->desc.bNumEndpoints; ++i)
1120		usb_remove_ep_devs(&alt->endpoint[i]);
1121	intf->ep_devs_created = 0;
1122}
1123
1124/**
1125 * usb_disable_endpoint -- Disable an endpoint by address
1126 * @dev: the device whose endpoint is being disabled
1127 * @epaddr: the endpoint's address.  Endpoint number for output,
1128 *	endpoint number + USB_DIR_IN for input
1129 * @reset_hardware: flag to erase any endpoint state stored in the
1130 *	controller hardware
1131 *
1132 * Disables the endpoint for URB submission and nukes all pending URBs.
1133 * If @reset_hardware is set then also deallocates hcd/hardware state
1134 * for the endpoint.
1135 */
1136void usb_disable_endpoint(struct usb_device *dev, unsigned int epaddr,
1137		bool reset_hardware)
1138{
1139	unsigned int epnum = epaddr & USB_ENDPOINT_NUMBER_MASK;
1140	struct usb_host_endpoint *ep;
1141
1142	if (!dev)
1143		return;
1144
1145	if (usb_endpoint_out(epaddr)) {
1146		ep = dev->ep_out[epnum];
1147		if (reset_hardware && epnum != 0)
1148			dev->ep_out[epnum] = NULL;
1149	} else {
1150		ep = dev->ep_in[epnum];
1151		if (reset_hardware && epnum != 0)
1152			dev->ep_in[epnum] = NULL;
1153	}
1154	if (ep) {
1155		ep->enabled = 0;
1156		usb_hcd_flush_endpoint(dev, ep);
1157		if (reset_hardware)
1158			usb_hcd_disable_endpoint(dev, ep);
1159	}
1160}
1161
1162/**
1163 * usb_reset_endpoint - Reset an endpoint's state.
1164 * @dev: the device whose endpoint is to be reset
1165 * @epaddr: the endpoint's address.  Endpoint number for output,
1166 *	endpoint number + USB_DIR_IN for input
1167 *
1168 * Resets any host-side endpoint state such as the toggle bit,
1169 * sequence number or current window.
1170 */
1171void usb_reset_endpoint(struct usb_device *dev, unsigned int epaddr)
1172{
1173	unsigned int epnum = epaddr & USB_ENDPOINT_NUMBER_MASK;
1174	struct usb_host_endpoint *ep;
1175
1176	if (usb_endpoint_out(epaddr))
1177		ep = dev->ep_out[epnum];
1178	else
1179		ep = dev->ep_in[epnum];
1180	if (ep)
1181		usb_hcd_reset_endpoint(dev, ep);
1182}
1183EXPORT_SYMBOL_GPL(usb_reset_endpoint);
1184
1185
1186/**
1187 * usb_disable_interface -- Disable all endpoints for an interface
1188 * @dev: the device whose interface is being disabled
1189 * @intf: pointer to the interface descriptor
1190 * @reset_hardware: flag to erase any endpoint state stored in the
1191 *	controller hardware
1192 *
1193 * Disables all the endpoints for the interface's current altsetting.
1194 */
1195void usb_disable_interface(struct usb_device *dev, struct usb_interface *intf,
1196		bool reset_hardware)
1197{
1198	struct usb_host_interface *alt = intf->cur_altsetting;
1199	int i;
1200
1201	for (i = 0; i < alt->desc.bNumEndpoints; ++i) {
1202		usb_disable_endpoint(dev,
1203				alt->endpoint[i].desc.bEndpointAddress,
1204				reset_hardware);
1205	}
1206}
1207
1208/*
1209 * usb_disable_device_endpoints -- Disable all endpoints for a device
1210 * @dev: the device whose endpoints are being disabled
1211 * @skip_ep0: 0 to disable endpoint 0, 1 to skip it.
1212 */
1213static void usb_disable_device_endpoints(struct usb_device *dev, int skip_ep0)
1214{
1215	struct usb_hcd *hcd = bus_to_hcd(dev->bus);
1216	int i;
1217
1218	if (hcd->driver->check_bandwidth) {
1219		/* First pass: Cancel URBs, leave endpoint pointers intact. */
1220		for (i = skip_ep0; i < 16; ++i) {
1221			usb_disable_endpoint(dev, i, false);
1222			usb_disable_endpoint(dev, i + USB_DIR_IN, false);
1223		}
1224		/* Remove endpoints from the host controller internal state */
1225		mutex_lock(hcd->bandwidth_mutex);
1226		usb_hcd_alloc_bandwidth(dev, NULL, NULL, NULL);
1227		mutex_unlock(hcd->bandwidth_mutex);
1228	}
1229	/* Second pass: remove endpoint pointers */
1230	for (i = skip_ep0; i < 16; ++i) {
1231		usb_disable_endpoint(dev, i, true);
1232		usb_disable_endpoint(dev, i + USB_DIR_IN, true);
1233	}
1234}
1235
1236/**
1237 * usb_disable_device - Disable all the endpoints for a USB device
1238 * @dev: the device whose endpoints are being disabled
1239 * @skip_ep0: 0 to disable endpoint 0, 1 to skip it.
1240 *
1241 * Disables all the device's endpoints, potentially including endpoint 0.
1242 * Deallocates hcd/hardware state for the endpoints (nuking all or most
1243 * pending urbs) and usbcore state for the interfaces, so that usbcore
1244 * must usb_set_configuration() before any interfaces could be used.
1245 */
1246void usb_disable_device(struct usb_device *dev, int skip_ep0)
1247{
1248	int i;
 
1249
1250	/* getting rid of interfaces will disconnect
1251	 * any drivers bound to them (a key side effect)
1252	 */
1253	if (dev->actconfig) {
1254		/*
1255		 * FIXME: In order to avoid self-deadlock involving the
1256		 * bandwidth_mutex, we have to mark all the interfaces
1257		 * before unregistering any of them.
1258		 */
1259		for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++)
1260			dev->actconfig->interface[i]->unregistering = 1;
1261
1262		for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++) {
1263			struct usb_interface	*interface;
1264
1265			/* remove this interface if it has been registered */
1266			interface = dev->actconfig->interface[i];
1267			if (!device_is_registered(&interface->dev))
1268				continue;
1269			dev_dbg(&dev->dev, "unregistering interface %s\n",
1270				dev_name(&interface->dev));
1271			remove_intf_ep_devs(interface);
1272			device_del(&interface->dev);
1273		}
1274
1275		/* Now that the interfaces are unbound, nobody should
1276		 * try to access them.
1277		 */
1278		for (i = 0; i < dev->actconfig->desc.bNumInterfaces; i++) {
1279			put_device(&dev->actconfig->interface[i]->dev);
1280			dev->actconfig->interface[i] = NULL;
1281		}
1282
1283		usb_disable_usb2_hardware_lpm(dev);
1284		usb_unlocked_disable_lpm(dev);
1285		usb_disable_ltm(dev);
1286
1287		dev->actconfig = NULL;
1288		if (dev->state == USB_STATE_CONFIGURED)
1289			usb_set_device_state(dev, USB_STATE_ADDRESS);
1290	}
1291
1292	dev_dbg(&dev->dev, "%s nuking %s URBs\n", __func__,
1293		skip_ep0 ? "non-ep0" : "all");
1294
1295	usb_disable_device_endpoints(dev, skip_ep0);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1296}
1297
1298/**
1299 * usb_enable_endpoint - Enable an endpoint for USB communications
1300 * @dev: the device whose interface is being enabled
1301 * @ep: the endpoint
1302 * @reset_ep: flag to reset the endpoint state
1303 *
1304 * Resets the endpoint state if asked, and sets dev->ep_{in,out} pointers.
1305 * For control endpoints, both the input and output sides are handled.
1306 */
1307void usb_enable_endpoint(struct usb_device *dev, struct usb_host_endpoint *ep,
1308		bool reset_ep)
1309{
1310	int epnum = usb_endpoint_num(&ep->desc);
1311	int is_out = usb_endpoint_dir_out(&ep->desc);
1312	int is_control = usb_endpoint_xfer_control(&ep->desc);
1313
1314	if (reset_ep)
1315		usb_hcd_reset_endpoint(dev, ep);
1316	if (is_out || is_control)
1317		dev->ep_out[epnum] = ep;
1318	if (!is_out || is_control)
1319		dev->ep_in[epnum] = ep;
1320	ep->enabled = 1;
1321}
1322
1323/**
1324 * usb_enable_interface - Enable all the endpoints for an interface
1325 * @dev: the device whose interface is being enabled
1326 * @intf: pointer to the interface descriptor
1327 * @reset_eps: flag to reset the endpoints' state
1328 *
1329 * Enables all the endpoints for the interface's current altsetting.
1330 */
1331void usb_enable_interface(struct usb_device *dev,
1332		struct usb_interface *intf, bool reset_eps)
1333{
1334	struct usb_host_interface *alt = intf->cur_altsetting;
1335	int i;
1336
1337	for (i = 0; i < alt->desc.bNumEndpoints; ++i)
1338		usb_enable_endpoint(dev, &alt->endpoint[i], reset_eps);
1339}
1340
1341/**
1342 * usb_set_interface - Makes a particular alternate setting be current
1343 * @dev: the device whose interface is being updated
1344 * @interface: the interface being updated
1345 * @alternate: the setting being chosen.
1346 * Context: !in_interrupt ()
1347 *
1348 * This is used to enable data transfers on interfaces that may not
1349 * be enabled by default.  Not all devices support such configurability.
1350 * Only the driver bound to an interface may change its setting.
1351 *
1352 * Within any given configuration, each interface may have several
1353 * alternative settings.  These are often used to control levels of
1354 * bandwidth consumption.  For example, the default setting for a high
1355 * speed interrupt endpoint may not send more than 64 bytes per microframe,
1356 * while interrupt transfers of up to 3KBytes per microframe are legal.
1357 * Also, isochronous endpoints may never be part of an
1358 * interface's default setting.  To access such bandwidth, alternate
1359 * interface settings must be made current.
1360 *
1361 * Note that in the Linux USB subsystem, bandwidth associated with
1362 * an endpoint in a given alternate setting is not reserved until an URB
1363 * is submitted that needs that bandwidth.  Some other operating systems
1364 * allocate bandwidth early, when a configuration is chosen.
1365 *
1366 * xHCI reserves bandwidth and configures the alternate setting in
1367 * usb_hcd_alloc_bandwidth(). If it fails the original interface altsetting
1368 * may be disabled. Drivers cannot rely on any particular alternate
1369 * setting being in effect after a failure.
1370 *
1371 * This call is synchronous, and may not be used in an interrupt context.
1372 * Also, drivers must not change altsettings while urbs are scheduled for
1373 * endpoints in that interface; all such urbs must first be completed
1374 * (perhaps forced by unlinking).
1375 *
1376 * Return: Zero on success, or else the status code returned by the
1377 * underlying usb_control_msg() call.
1378 */
1379int usb_set_interface(struct usb_device *dev, int interface, int alternate)
1380{
1381	struct usb_interface *iface;
1382	struct usb_host_interface *alt;
1383	struct usb_hcd *hcd = bus_to_hcd(dev->bus);
1384	int i, ret, manual = 0;
 
1385	unsigned int epaddr;
1386	unsigned int pipe;
1387
1388	if (dev->state == USB_STATE_SUSPENDED)
1389		return -EHOSTUNREACH;
1390
1391	iface = usb_ifnum_to_if(dev, interface);
1392	if (!iface) {
1393		dev_dbg(&dev->dev, "selecting invalid interface %d\n",
1394			interface);
1395		return -EINVAL;
1396	}
1397	if (iface->unregistering)
1398		return -ENODEV;
1399
1400	alt = usb_altnum_to_altsetting(iface, alternate);
1401	if (!alt) {
1402		dev_warn(&dev->dev, "selecting invalid altsetting %d\n",
1403			 alternate);
1404		return -EINVAL;
1405	}
1406	/*
1407	 * usb3 hosts configure the interface in usb_hcd_alloc_bandwidth,
1408	 * including freeing dropped endpoint ring buffers.
1409	 * Make sure the interface endpoints are flushed before that
1410	 */
1411	usb_disable_interface(dev, iface, false);
1412
1413	/* Make sure we have enough bandwidth for this alternate interface.
1414	 * Remove the current alt setting and add the new alt setting.
1415	 */
1416	mutex_lock(hcd->bandwidth_mutex);
1417	/* Disable LPM, and re-enable it once the new alt setting is installed,
1418	 * so that the xHCI driver can recalculate the U1/U2 timeouts.
1419	 */
1420	if (usb_disable_lpm(dev)) {
1421		dev_err(&iface->dev, "%s Failed to disable LPM\n", __func__);
1422		mutex_unlock(hcd->bandwidth_mutex);
1423		return -ENOMEM;
1424	}
1425	/* Changing alt-setting also frees any allocated streams */
1426	for (i = 0; i < iface->cur_altsetting->desc.bNumEndpoints; i++)
1427		iface->cur_altsetting->endpoint[i].streams = 0;
1428
1429	ret = usb_hcd_alloc_bandwidth(dev, NULL, iface->cur_altsetting, alt);
1430	if (ret < 0) {
1431		dev_info(&dev->dev, "Not enough bandwidth for altsetting %d\n",
1432				alternate);
1433		usb_enable_lpm(dev);
1434		mutex_unlock(hcd->bandwidth_mutex);
1435		return ret;
1436	}
1437
1438	if (dev->quirks & USB_QUIRK_NO_SET_INTF)
1439		ret = -EPIPE;
1440	else
1441		ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
1442				   USB_REQ_SET_INTERFACE, USB_RECIP_INTERFACE,
1443				   alternate, interface, NULL, 0, 5000);
1444
1445	/* 9.4.10 says devices don't need this and are free to STALL the
1446	 * request if the interface only has one alternate setting.
1447	 */
1448	if (ret == -EPIPE && iface->num_altsetting == 1) {
1449		dev_dbg(&dev->dev,
1450			"manual set_interface for iface %d, alt %d\n",
1451			interface, alternate);
1452		manual = 1;
1453	} else if (ret < 0) {
1454		/* Re-instate the old alt setting */
1455		usb_hcd_alloc_bandwidth(dev, NULL, alt, iface->cur_altsetting);
1456		usb_enable_lpm(dev);
1457		mutex_unlock(hcd->bandwidth_mutex);
1458		return ret;
1459	}
1460	mutex_unlock(hcd->bandwidth_mutex);
1461
1462	/* FIXME drivers shouldn't need to replicate/bugfix the logic here
1463	 * when they implement async or easily-killable versions of this or
1464	 * other "should-be-internal" functions (like clear_halt).
1465	 * should hcd+usbcore postprocess control requests?
1466	 */
1467
1468	/* prevent submissions using previous endpoint settings */
1469	if (iface->cur_altsetting != alt) {
1470		remove_intf_ep_devs(iface);
1471		usb_remove_sysfs_intf_files(iface);
1472	}
1473	usb_disable_interface(dev, iface, true);
1474
1475	iface->cur_altsetting = alt;
1476
1477	/* Now that the interface is installed, re-enable LPM. */
1478	usb_unlocked_enable_lpm(dev);
1479
1480	/* If the interface only has one altsetting and the device didn't
1481	 * accept the request, we attempt to carry out the equivalent action
1482	 * by manually clearing the HALT feature for each endpoint in the
1483	 * new altsetting.
1484	 */
1485	if (manual) {
 
 
1486		for (i = 0; i < alt->desc.bNumEndpoints; i++) {
1487			epaddr = alt->endpoint[i].desc.bEndpointAddress;
1488			pipe = __create_pipe(dev,
1489					USB_ENDPOINT_NUMBER_MASK & epaddr) |
1490					(usb_endpoint_out(epaddr) ?
1491					USB_DIR_OUT : USB_DIR_IN);
1492
1493			usb_clear_halt(dev, pipe);
1494		}
1495	}
1496
1497	/* 9.1.1.5: reset toggles for all endpoints in the new altsetting
1498	 *
1499	 * Note:
1500	 * Despite EP0 is always present in all interfaces/AS, the list of
1501	 * endpoints from the descriptor does not contain EP0. Due to its
1502	 * omnipresence one might expect EP0 being considered "affected" by
1503	 * any SetInterface request and hence assume toggles need to be reset.
1504	 * However, EP0 toggles are re-synced for every individual transfer
1505	 * during the SETUP stage - hence EP0 toggles are "don't care" here.
1506	 * (Likewise, EP0 never "halts" on well designed devices.)
1507	 */
1508	usb_enable_interface(dev, iface, true);
1509	if (device_is_registered(&iface->dev)) {
1510		usb_create_sysfs_intf_files(iface);
1511		create_intf_ep_devs(iface);
1512	}
1513	return 0;
1514}
1515EXPORT_SYMBOL_GPL(usb_set_interface);
1516
1517/**
1518 * usb_reset_configuration - lightweight device reset
1519 * @dev: the device whose configuration is being reset
1520 *
1521 * This issues a standard SET_CONFIGURATION request to the device using
1522 * the current configuration.  The effect is to reset most USB-related
1523 * state in the device, including interface altsettings (reset to zero),
1524 * endpoint halts (cleared), and endpoint state (only for bulk and interrupt
1525 * endpoints).  Other usbcore state is unchanged, including bindings of
1526 * usb device drivers to interfaces.
1527 *
1528 * Because this affects multiple interfaces, avoid using this with composite
1529 * (multi-interface) devices.  Instead, the driver for each interface may
1530 * use usb_set_interface() on the interfaces it claims.  Be careful though;
1531 * some devices don't support the SET_INTERFACE request, and others won't
1532 * reset all the interface state (notably endpoint state).  Resetting the whole
1533 * configuration would affect other drivers' interfaces.
1534 *
1535 * The caller must own the device lock.
1536 *
1537 * Return: Zero on success, else a negative error code.
1538 *
1539 * If this routine fails the device will probably be in an unusable state
1540 * with endpoints disabled, and interfaces only partially enabled.
1541 */
1542int usb_reset_configuration(struct usb_device *dev)
1543{
1544	int			i, retval;
1545	struct usb_host_config	*config;
1546	struct usb_hcd *hcd = bus_to_hcd(dev->bus);
1547
1548	if (dev->state == USB_STATE_SUSPENDED)
1549		return -EHOSTUNREACH;
1550
1551	/* caller must have locked the device and must own
1552	 * the usb bus readlock (so driver bindings are stable);
1553	 * calls during probe() are fine
1554	 */
1555
1556	usb_disable_device_endpoints(dev, 1); /* skip ep0*/
 
 
 
1557
1558	config = dev->actconfig;
1559	retval = 0;
1560	mutex_lock(hcd->bandwidth_mutex);
1561	/* Disable LPM, and re-enable it once the configuration is reset, so
1562	 * that the xHCI driver can recalculate the U1/U2 timeouts.
1563	 */
1564	if (usb_disable_lpm(dev)) {
1565		dev_err(&dev->dev, "%s Failed to disable LPM\n", __func__);
1566		mutex_unlock(hcd->bandwidth_mutex);
1567		return -ENOMEM;
1568	}
 
 
 
 
1569
1570	/* xHCI adds all endpoints in usb_hcd_alloc_bandwidth */
1571	retval = usb_hcd_alloc_bandwidth(dev, config, NULL, NULL);
 
 
 
 
 
 
 
 
1572	if (retval < 0) {
 
 
 
 
 
 
 
 
 
 
 
 
1573		usb_enable_lpm(dev);
1574		mutex_unlock(hcd->bandwidth_mutex);
1575		return retval;
1576	}
1577	retval = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
1578			USB_REQ_SET_CONFIGURATION, 0,
1579			config->desc.bConfigurationValue, 0,
1580			NULL, 0, USB_CTRL_SET_TIMEOUT);
1581	if (retval < 0) {
1582		usb_hcd_alloc_bandwidth(dev, NULL, NULL, NULL);
1583		usb_enable_lpm(dev);
1584		mutex_unlock(hcd->bandwidth_mutex);
1585		return retval;
1586	}
1587	mutex_unlock(hcd->bandwidth_mutex);
1588
1589	/* re-init hc/hcd interface/endpoint state */
1590	for (i = 0; i < config->desc.bNumInterfaces; i++) {
1591		struct usb_interface *intf = config->interface[i];
1592		struct usb_host_interface *alt;
1593
1594		alt = usb_altnum_to_altsetting(intf, 0);
1595
1596		/* No altsetting 0?  We'll assume the first altsetting.
1597		 * We could use a GetInterface call, but if a device is
1598		 * so non-compliant that it doesn't have altsetting 0
1599		 * then I wouldn't trust its reply anyway.
1600		 */
1601		if (!alt)
1602			alt = &intf->altsetting[0];
1603
1604		if (alt != intf->cur_altsetting) {
1605			remove_intf_ep_devs(intf);
1606			usb_remove_sysfs_intf_files(intf);
1607		}
1608		intf->cur_altsetting = alt;
1609		usb_enable_interface(dev, intf, true);
1610		if (device_is_registered(&intf->dev)) {
1611			usb_create_sysfs_intf_files(intf);
1612			create_intf_ep_devs(intf);
1613		}
1614	}
1615	/* Now that the interfaces are installed, re-enable LPM. */
1616	usb_unlocked_enable_lpm(dev);
1617	return 0;
1618}
1619EXPORT_SYMBOL_GPL(usb_reset_configuration);
1620
1621static void usb_release_interface(struct device *dev)
1622{
1623	struct usb_interface *intf = to_usb_interface(dev);
1624	struct usb_interface_cache *intfc =
1625			altsetting_to_usb_interface_cache(intf->altsetting);
1626
1627	kref_put(&intfc->ref, usb_release_interface_cache);
1628	usb_put_dev(interface_to_usbdev(intf));
1629	of_node_put(dev->of_node);
1630	kfree(intf);
1631}
1632
1633/*
1634 * usb_deauthorize_interface - deauthorize an USB interface
1635 *
1636 * @intf: USB interface structure
1637 */
1638void usb_deauthorize_interface(struct usb_interface *intf)
1639{
1640	struct device *dev = &intf->dev;
1641
1642	device_lock(dev->parent);
1643
1644	if (intf->authorized) {
1645		device_lock(dev);
1646		intf->authorized = 0;
1647		device_unlock(dev);
1648
1649		usb_forced_unbind_intf(intf);
1650	}
1651
1652	device_unlock(dev->parent);
1653}
1654
1655/*
1656 * usb_authorize_interface - authorize an USB interface
1657 *
1658 * @intf: USB interface structure
1659 */
1660void usb_authorize_interface(struct usb_interface *intf)
1661{
1662	struct device *dev = &intf->dev;
1663
1664	if (!intf->authorized) {
1665		device_lock(dev);
1666		intf->authorized = 1; /* authorize interface */
1667		device_unlock(dev);
1668	}
1669}
1670
1671static int usb_if_uevent(struct device *dev, struct kobj_uevent_env *env)
1672{
1673	struct usb_device *usb_dev;
1674	struct usb_interface *intf;
1675	struct usb_host_interface *alt;
1676
1677	intf = to_usb_interface(dev);
1678	usb_dev = interface_to_usbdev(intf);
1679	alt = intf->cur_altsetting;
1680
1681	if (add_uevent_var(env, "INTERFACE=%d/%d/%d",
1682		   alt->desc.bInterfaceClass,
1683		   alt->desc.bInterfaceSubClass,
1684		   alt->desc.bInterfaceProtocol))
1685		return -ENOMEM;
1686
1687	if (add_uevent_var(env,
1688		   "MODALIAS=usb:"
1689		   "v%04Xp%04Xd%04Xdc%02Xdsc%02Xdp%02Xic%02Xisc%02Xip%02Xin%02X",
1690		   le16_to_cpu(usb_dev->descriptor.idVendor),
1691		   le16_to_cpu(usb_dev->descriptor.idProduct),
1692		   le16_to_cpu(usb_dev->descriptor.bcdDevice),
1693		   usb_dev->descriptor.bDeviceClass,
1694		   usb_dev->descriptor.bDeviceSubClass,
1695		   usb_dev->descriptor.bDeviceProtocol,
1696		   alt->desc.bInterfaceClass,
1697		   alt->desc.bInterfaceSubClass,
1698		   alt->desc.bInterfaceProtocol,
1699		   alt->desc.bInterfaceNumber))
1700		return -ENOMEM;
1701
1702	return 0;
1703}
1704
 
 
 
 
 
 
 
 
1705struct device_type usb_if_device_type = {
1706	.name =		"usb_interface",
1707	.release =	usb_release_interface,
1708	.uevent =	usb_if_uevent,
1709};
1710
1711static struct usb_interface_assoc_descriptor *find_iad(struct usb_device *dev,
1712						struct usb_host_config *config,
1713						u8 inum)
1714{
1715	struct usb_interface_assoc_descriptor *retval = NULL;
1716	struct usb_interface_assoc_descriptor *intf_assoc;
1717	int first_intf;
1718	int last_intf;
1719	int i;
1720
1721	for (i = 0; (i < USB_MAXIADS && config->intf_assoc[i]); i++) {
1722		intf_assoc = config->intf_assoc[i];
1723		if (intf_assoc->bInterfaceCount == 0)
1724			continue;
1725
1726		first_intf = intf_assoc->bFirstInterface;
1727		last_intf = first_intf + (intf_assoc->bInterfaceCount - 1);
1728		if (inum >= first_intf && inum <= last_intf) {
1729			if (!retval)
1730				retval = intf_assoc;
1731			else
1732				dev_err(&dev->dev, "Interface #%d referenced"
1733					" by multiple IADs\n", inum);
1734		}
1735	}
1736
1737	return retval;
1738}
1739
1740
1741/*
1742 * Internal function to queue a device reset
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1743 * See usb_queue_reset_device() for more details
1744 */
1745static void __usb_queue_reset_device(struct work_struct *ws)
1746{
1747	int rc;
1748	struct usb_interface *iface =
1749		container_of(ws, struct usb_interface, reset_ws);
1750	struct usb_device *udev = interface_to_usbdev(iface);
1751
1752	rc = usb_lock_device_for_reset(udev, iface);
1753	if (rc >= 0) {
 
1754		usb_reset_device(udev);
 
1755		usb_unlock_device(udev);
1756	}
1757	usb_put_intf(iface);	/* Undo _get_ in usb_queue_reset_device() */
1758}
1759
1760
1761/*
1762 * usb_set_configuration - Makes a particular device setting be current
1763 * @dev: the device whose configuration is being updated
1764 * @configuration: the configuration being chosen.
1765 * Context: !in_interrupt(), caller owns the device lock
1766 *
1767 * This is used to enable non-default device modes.  Not all devices
1768 * use this kind of configurability; many devices only have one
1769 * configuration.
1770 *
1771 * @configuration is the value of the configuration to be installed.
1772 * According to the USB spec (e.g. section 9.1.1.5), configuration values
1773 * must be non-zero; a value of zero indicates that the device in
1774 * unconfigured.  However some devices erroneously use 0 as one of their
1775 * configuration values.  To help manage such devices, this routine will
1776 * accept @configuration = -1 as indicating the device should be put in
1777 * an unconfigured state.
1778 *
1779 * USB device configurations may affect Linux interoperability,
1780 * power consumption and the functionality available.  For example,
1781 * the default configuration is limited to using 100mA of bus power,
1782 * so that when certain device functionality requires more power,
1783 * and the device is bus powered, that functionality should be in some
1784 * non-default device configuration.  Other device modes may also be
1785 * reflected as configuration options, such as whether two ISDN
1786 * channels are available independently; and choosing between open
1787 * standard device protocols (like CDC) or proprietary ones.
1788 *
1789 * Note that a non-authorized device (dev->authorized == 0) will only
1790 * be put in unconfigured mode.
1791 *
1792 * Note that USB has an additional level of device configurability,
1793 * associated with interfaces.  That configurability is accessed using
1794 * usb_set_interface().
1795 *
1796 * This call is synchronous. The calling context must be able to sleep,
1797 * must own the device lock, and must not hold the driver model's USB
1798 * bus mutex; usb interface driver probe() methods cannot use this routine.
1799 *
1800 * Returns zero on success, or else the status code returned by the
1801 * underlying call that failed.  On successful completion, each interface
1802 * in the original device configuration has been destroyed, and each one
1803 * in the new configuration has been probed by all relevant usb device
1804 * drivers currently known to the kernel.
1805 */
1806int usb_set_configuration(struct usb_device *dev, int configuration)
1807{
1808	int i, ret;
1809	struct usb_host_config *cp = NULL;
1810	struct usb_interface **new_interfaces = NULL;
1811	struct usb_hcd *hcd = bus_to_hcd(dev->bus);
1812	int n, nintf;
1813
1814	if (dev->authorized == 0 || configuration == -1)
1815		configuration = 0;
1816	else {
1817		for (i = 0; i < dev->descriptor.bNumConfigurations; i++) {
1818			if (dev->config[i].desc.bConfigurationValue ==
1819					configuration) {
1820				cp = &dev->config[i];
1821				break;
1822			}
1823		}
1824	}
1825	if ((!cp && configuration != 0))
1826		return -EINVAL;
1827
1828	/* The USB spec says configuration 0 means unconfigured.
1829	 * But if a device includes a configuration numbered 0,
1830	 * we will accept it as a correctly configured state.
1831	 * Use -1 if you really want to unconfigure the device.
1832	 */
1833	if (cp && configuration == 0)
1834		dev_warn(&dev->dev, "config 0 descriptor??\n");
1835
1836	/* Allocate memory for new interfaces before doing anything else,
1837	 * so that if we run out then nothing will have changed. */
1838	n = nintf = 0;
1839	if (cp) {
1840		nintf = cp->desc.bNumInterfaces;
1841		new_interfaces = kmalloc_array(nintf, sizeof(*new_interfaces),
1842					       GFP_NOIO);
1843		if (!new_interfaces)
 
1844			return -ENOMEM;
 
1845
1846		for (; n < nintf; ++n) {
1847			new_interfaces[n] = kzalloc(
1848					sizeof(struct usb_interface),
1849					GFP_NOIO);
1850			if (!new_interfaces[n]) {
 
1851				ret = -ENOMEM;
1852free_interfaces:
1853				while (--n >= 0)
1854					kfree(new_interfaces[n]);
1855				kfree(new_interfaces);
1856				return ret;
1857			}
1858		}
1859
1860		i = dev->bus_mA - usb_get_max_power(dev, cp);
1861		if (i < 0)
1862			dev_warn(&dev->dev, "new config #%d exceeds power "
1863					"limit by %dmA\n",
1864					configuration, -i);
1865	}
1866
1867	/* Wake up the device so we can send it the Set-Config request */
1868	ret = usb_autoresume_device(dev);
1869	if (ret)
1870		goto free_interfaces;
1871
1872	/* if it's already configured, clear out old state first.
1873	 * getting rid of old interfaces means unbinding their drivers.
1874	 */
1875	if (dev->state != USB_STATE_ADDRESS)
1876		usb_disable_device(dev, 1);	/* Skip ep0 */
1877
1878	/* Get rid of pending async Set-Config requests for this device */
1879	cancel_async_set_config(dev);
1880
1881	/* Make sure we have bandwidth (and available HCD resources) for this
1882	 * configuration.  Remove endpoints from the schedule if we're dropping
1883	 * this configuration to set configuration 0.  After this point, the
1884	 * host controller will not allow submissions to dropped endpoints.  If
1885	 * this call fails, the device state is unchanged.
1886	 */
1887	mutex_lock(hcd->bandwidth_mutex);
1888	/* Disable LPM, and re-enable it once the new configuration is
1889	 * installed, so that the xHCI driver can recalculate the U1/U2
1890	 * timeouts.
1891	 */
1892	if (dev->actconfig && usb_disable_lpm(dev)) {
1893		dev_err(&dev->dev, "%s Failed to disable LPM\n", __func__);
1894		mutex_unlock(hcd->bandwidth_mutex);
1895		ret = -ENOMEM;
1896		goto free_interfaces;
1897	}
1898	ret = usb_hcd_alloc_bandwidth(dev, cp, NULL, NULL);
1899	if (ret < 0) {
1900		if (dev->actconfig)
1901			usb_enable_lpm(dev);
1902		mutex_unlock(hcd->bandwidth_mutex);
1903		usb_autosuspend_device(dev);
1904		goto free_interfaces;
1905	}
1906
1907	/*
1908	 * Initialize the new interface structures and the
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1909	 * hc/hcd/usbcore interface/endpoint state.
1910	 */
1911	for (i = 0; i < nintf; ++i) {
1912		struct usb_interface_cache *intfc;
1913		struct usb_interface *intf;
1914		struct usb_host_interface *alt;
1915		u8 ifnum;
1916
1917		cp->interface[i] = intf = new_interfaces[i];
1918		intfc = cp->intf_cache[i];
1919		intf->altsetting = intfc->altsetting;
1920		intf->num_altsetting = intfc->num_altsetting;
1921		intf->authorized = !!HCD_INTF_AUTHORIZED(hcd);
1922		kref_get(&intfc->ref);
1923
1924		alt = usb_altnum_to_altsetting(intf, 0);
1925
1926		/* No altsetting 0?  We'll assume the first altsetting.
1927		 * We could use a GetInterface call, but if a device is
1928		 * so non-compliant that it doesn't have altsetting 0
1929		 * then I wouldn't trust its reply anyway.
1930		 */
1931		if (!alt)
1932			alt = &intf->altsetting[0];
1933
1934		ifnum = alt->desc.bInterfaceNumber;
1935		intf->intf_assoc = find_iad(dev, cp, ifnum);
1936		intf->cur_altsetting = alt;
1937		usb_enable_interface(dev, intf, true);
1938		intf->dev.parent = &dev->dev;
1939		if (usb_of_has_combined_node(dev)) {
1940			device_set_of_node_from_dev(&intf->dev, &dev->dev);
1941		} else {
1942			intf->dev.of_node = usb_of_get_interface_node(dev,
1943					configuration, ifnum);
1944		}
1945		ACPI_COMPANION_SET(&intf->dev, ACPI_COMPANION(&dev->dev));
1946		intf->dev.driver = NULL;
1947		intf->dev.bus = &usb_bus_type;
1948		intf->dev.type = &usb_if_device_type;
1949		intf->dev.groups = usb_interface_groups;
1950		/*
1951		 * Please refer to usb_alloc_dev() to see why we set
1952		 * dma_mask and dma_pfn_offset.
1953		 */
1954		intf->dev.dma_mask = dev->dev.dma_mask;
1955		intf->dev.dma_pfn_offset = dev->dev.dma_pfn_offset;
1956		INIT_WORK(&intf->reset_ws, __usb_queue_reset_device);
1957		intf->minor = -1;
1958		device_initialize(&intf->dev);
1959		pm_runtime_no_callbacks(&intf->dev);
1960		dev_set_name(&intf->dev, "%d-%s:%d.%d", dev->bus->busnum,
1961				dev->devpath, configuration, ifnum);
1962		usb_get_dev(dev);
1963	}
1964	kfree(new_interfaces);
1965
1966	ret = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
1967			      USB_REQ_SET_CONFIGURATION, 0, configuration, 0,
1968			      NULL, 0, USB_CTRL_SET_TIMEOUT);
1969	if (ret < 0 && cp) {
1970		/*
1971		 * All the old state is gone, so what else can we do?
1972		 * The device is probably useless now anyway.
1973		 */
1974		usb_hcd_alloc_bandwidth(dev, NULL, NULL, NULL);
1975		for (i = 0; i < nintf; ++i) {
1976			usb_disable_interface(dev, cp->interface[i], true);
1977			put_device(&cp->interface[i]->dev);
1978			cp->interface[i] = NULL;
1979		}
1980		cp = NULL;
1981	}
1982
1983	dev->actconfig = cp;
1984	mutex_unlock(hcd->bandwidth_mutex);
1985
1986	if (!cp) {
1987		usb_set_device_state(dev, USB_STATE_ADDRESS);
1988
1989		/* Leave LPM disabled while the device is unconfigured. */
1990		usb_autosuspend_device(dev);
1991		return ret;
1992	}
1993	usb_set_device_state(dev, USB_STATE_CONFIGURED);
1994
1995	if (cp->string == NULL &&
1996			!(dev->quirks & USB_QUIRK_CONFIG_INTF_STRINGS))
1997		cp->string = usb_cache_string(dev, cp->desc.iConfiguration);
1998
1999	/* Now that the interfaces are installed, re-enable LPM. */
2000	usb_unlocked_enable_lpm(dev);
2001	/* Enable LTM if it was turned off by usb_disable_device. */
2002	usb_enable_ltm(dev);
2003
2004	/* Now that all the interfaces are set up, register them
2005	 * to trigger binding of drivers to interfaces.  probe()
2006	 * routines may install different altsettings and may
2007	 * claim() any interfaces not yet bound.  Many class drivers
2008	 * need that: CDC, audio, video, etc.
2009	 */
2010	for (i = 0; i < nintf; ++i) {
2011		struct usb_interface *intf = cp->interface[i];
2012
2013		if (intf->dev.of_node &&
2014		    !of_device_is_available(intf->dev.of_node)) {
2015			dev_info(&dev->dev, "skipping disabled interface %d\n",
2016				 intf->cur_altsetting->desc.bInterfaceNumber);
2017			continue;
2018		}
2019
2020		dev_dbg(&dev->dev,
2021			"adding %s (config #%d, interface %d)\n",
2022			dev_name(&intf->dev), configuration,
2023			intf->cur_altsetting->desc.bInterfaceNumber);
2024		device_enable_async_suspend(&intf->dev);
2025		ret = device_add(&intf->dev);
2026		if (ret != 0) {
2027			dev_err(&dev->dev, "device_add(%s) --> %d\n",
2028				dev_name(&intf->dev), ret);
2029			continue;
2030		}
2031		create_intf_ep_devs(intf);
2032	}
2033
2034	usb_autosuspend_device(dev);
2035	return 0;
2036}
2037EXPORT_SYMBOL_GPL(usb_set_configuration);
2038
2039static LIST_HEAD(set_config_list);
2040static DEFINE_SPINLOCK(set_config_lock);
2041
2042struct set_config_request {
2043	struct usb_device	*udev;
2044	int			config;
2045	struct work_struct	work;
2046	struct list_head	node;
2047};
2048
2049/* Worker routine for usb_driver_set_configuration() */
2050static void driver_set_config_work(struct work_struct *work)
2051{
2052	struct set_config_request *req =
2053		container_of(work, struct set_config_request, work);
2054	struct usb_device *udev = req->udev;
2055
2056	usb_lock_device(udev);
2057	spin_lock(&set_config_lock);
2058	list_del(&req->node);
2059	spin_unlock(&set_config_lock);
2060
2061	if (req->config >= -1)		/* Is req still valid? */
2062		usb_set_configuration(udev, req->config);
2063	usb_unlock_device(udev);
2064	usb_put_dev(udev);
2065	kfree(req);
2066}
2067
2068/* Cancel pending Set-Config requests for a device whose configuration
2069 * was just changed
2070 */
2071static void cancel_async_set_config(struct usb_device *udev)
2072{
2073	struct set_config_request *req;
2074
2075	spin_lock(&set_config_lock);
2076	list_for_each_entry(req, &set_config_list, node) {
2077		if (req->udev == udev)
2078			req->config = -999;	/* Mark as cancelled */
2079	}
2080	spin_unlock(&set_config_lock);
2081}
2082
2083/**
2084 * usb_driver_set_configuration - Provide a way for drivers to change device configurations
2085 * @udev: the device whose configuration is being updated
2086 * @config: the configuration being chosen.
2087 * Context: In process context, must be able to sleep
2088 *
2089 * Device interface drivers are not allowed to change device configurations.
2090 * This is because changing configurations will destroy the interface the
2091 * driver is bound to and create new ones; it would be like a floppy-disk
2092 * driver telling the computer to replace the floppy-disk drive with a
2093 * tape drive!
2094 *
2095 * Still, in certain specialized circumstances the need may arise.  This
2096 * routine gets around the normal restrictions by using a work thread to
2097 * submit the change-config request.
2098 *
2099 * Return: 0 if the request was successfully queued, error code otherwise.
2100 * The caller has no way to know whether the queued request will eventually
2101 * succeed.
2102 */
2103int usb_driver_set_configuration(struct usb_device *udev, int config)
2104{
2105	struct set_config_request *req;
2106
2107	req = kmalloc(sizeof(*req), GFP_KERNEL);
2108	if (!req)
2109		return -ENOMEM;
2110	req->udev = udev;
2111	req->config = config;
2112	INIT_WORK(&req->work, driver_set_config_work);
2113
2114	spin_lock(&set_config_lock);
2115	list_add(&req->node, &set_config_list);
2116	spin_unlock(&set_config_lock);
2117
2118	usb_get_dev(udev);
2119	schedule_work(&req->work);
2120	return 0;
2121}
2122EXPORT_SYMBOL_GPL(usb_driver_set_configuration);
2123
2124/**
2125 * cdc_parse_cdc_header - parse the extra headers present in CDC devices
2126 * @hdr: the place to put the results of the parsing
2127 * @intf: the interface for which parsing is requested
2128 * @buffer: pointer to the extra headers to be parsed
2129 * @buflen: length of the extra headers
2130 *
2131 * This evaluates the extra headers present in CDC devices which
2132 * bind the interfaces for data and control and provide details
2133 * about the capabilities of the device.
2134 *
2135 * Return: number of descriptors parsed or -EINVAL
2136 * if the header is contradictory beyond salvage
2137 */
2138
2139int cdc_parse_cdc_header(struct usb_cdc_parsed_header *hdr,
2140				struct usb_interface *intf,
2141				u8 *buffer,
2142				int buflen)
2143{
2144	/* duplicates are ignored */
2145	struct usb_cdc_union_desc *union_header = NULL;
2146
2147	/* duplicates are not tolerated */
2148	struct usb_cdc_header_desc *header = NULL;
2149	struct usb_cdc_ether_desc *ether = NULL;
2150	struct usb_cdc_mdlm_detail_desc *detail = NULL;
2151	struct usb_cdc_mdlm_desc *desc = NULL;
2152
2153	unsigned int elength;
2154	int cnt = 0;
2155
2156	memset(hdr, 0x00, sizeof(struct usb_cdc_parsed_header));
2157	hdr->phonet_magic_present = false;
2158	while (buflen > 0) {
2159		elength = buffer[0];
2160		if (!elength) {
2161			dev_err(&intf->dev, "skipping garbage byte\n");
2162			elength = 1;
2163			goto next_desc;
2164		}
2165		if ((buflen < elength) || (elength < 3)) {
2166			dev_err(&intf->dev, "invalid descriptor buffer length\n");
2167			break;
2168		}
2169		if (buffer[1] != USB_DT_CS_INTERFACE) {
2170			dev_err(&intf->dev, "skipping garbage\n");
2171			goto next_desc;
2172		}
2173
2174		switch (buffer[2]) {
2175		case USB_CDC_UNION_TYPE: /* we've found it */
2176			if (elength < sizeof(struct usb_cdc_union_desc))
2177				goto next_desc;
2178			if (union_header) {
2179				dev_err(&intf->dev, "More than one union descriptor, skipping ...\n");
2180				goto next_desc;
2181			}
2182			union_header = (struct usb_cdc_union_desc *)buffer;
2183			break;
2184		case USB_CDC_COUNTRY_TYPE:
2185			if (elength < sizeof(struct usb_cdc_country_functional_desc))
2186				goto next_desc;
2187			hdr->usb_cdc_country_functional_desc =
2188				(struct usb_cdc_country_functional_desc *)buffer;
2189			break;
2190		case USB_CDC_HEADER_TYPE:
2191			if (elength != sizeof(struct usb_cdc_header_desc))
2192				goto next_desc;
2193			if (header)
2194				return -EINVAL;
2195			header = (struct usb_cdc_header_desc *)buffer;
2196			break;
2197		case USB_CDC_ACM_TYPE:
2198			if (elength < sizeof(struct usb_cdc_acm_descriptor))
2199				goto next_desc;
2200			hdr->usb_cdc_acm_descriptor =
2201				(struct usb_cdc_acm_descriptor *)buffer;
2202			break;
2203		case USB_CDC_ETHERNET_TYPE:
2204			if (elength != sizeof(struct usb_cdc_ether_desc))
2205				goto next_desc;
2206			if (ether)
2207				return -EINVAL;
2208			ether = (struct usb_cdc_ether_desc *)buffer;
2209			break;
2210		case USB_CDC_CALL_MANAGEMENT_TYPE:
2211			if (elength < sizeof(struct usb_cdc_call_mgmt_descriptor))
2212				goto next_desc;
2213			hdr->usb_cdc_call_mgmt_descriptor =
2214				(struct usb_cdc_call_mgmt_descriptor *)buffer;
2215			break;
2216		case USB_CDC_DMM_TYPE:
2217			if (elength < sizeof(struct usb_cdc_dmm_desc))
2218				goto next_desc;
2219			hdr->usb_cdc_dmm_desc =
2220				(struct usb_cdc_dmm_desc *)buffer;
2221			break;
2222		case USB_CDC_MDLM_TYPE:
2223			if (elength < sizeof(struct usb_cdc_mdlm_desc))
2224				goto next_desc;
2225			if (desc)
2226				return -EINVAL;
2227			desc = (struct usb_cdc_mdlm_desc *)buffer;
2228			break;
2229		case USB_CDC_MDLM_DETAIL_TYPE:
2230			if (elength < sizeof(struct usb_cdc_mdlm_detail_desc))
2231				goto next_desc;
2232			if (detail)
2233				return -EINVAL;
2234			detail = (struct usb_cdc_mdlm_detail_desc *)buffer;
2235			break;
2236		case USB_CDC_NCM_TYPE:
2237			if (elength < sizeof(struct usb_cdc_ncm_desc))
2238				goto next_desc;
2239			hdr->usb_cdc_ncm_desc = (struct usb_cdc_ncm_desc *)buffer;
2240			break;
2241		case USB_CDC_MBIM_TYPE:
2242			if (elength < sizeof(struct usb_cdc_mbim_desc))
2243				goto next_desc;
2244
2245			hdr->usb_cdc_mbim_desc = (struct usb_cdc_mbim_desc *)buffer;
2246			break;
2247		case USB_CDC_MBIM_EXTENDED_TYPE:
2248			if (elength < sizeof(struct usb_cdc_mbim_extended_desc))
2249				break;
2250			hdr->usb_cdc_mbim_extended_desc =
2251				(struct usb_cdc_mbim_extended_desc *)buffer;
2252			break;
2253		case CDC_PHONET_MAGIC_NUMBER:
2254			hdr->phonet_magic_present = true;
2255			break;
2256		default:
2257			/*
2258			 * there are LOTS more CDC descriptors that
2259			 * could legitimately be found here.
2260			 */
2261			dev_dbg(&intf->dev, "Ignoring descriptor: type %02x, length %ud\n",
2262					buffer[2], elength);
2263			goto next_desc;
2264		}
2265		cnt++;
2266next_desc:
2267		buflen -= elength;
2268		buffer += elength;
2269	}
2270	hdr->usb_cdc_union_desc = union_header;
2271	hdr->usb_cdc_header_desc = header;
2272	hdr->usb_cdc_mdlm_detail_desc = detail;
2273	hdr->usb_cdc_mdlm_desc = desc;
2274	hdr->usb_cdc_ether_desc = ether;
2275	return cnt;
2276}
2277
2278EXPORT_SYMBOL(cdc_parse_cdc_header);