Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | #include <linux/module.h> |
| 2 | #include <linux/string.h> |
| 3 | #include <linux/bitops.h> |
| 4 | #include <linux/slab.h> |
Alan Stern | d617bc8 | 2007-08-02 15:04:52 -0400 | [diff] [blame] | 5 | #include <linux/log2.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 6 | #include <linux/usb.h> |
Oliver Neukum | 51a2f07 | 2007-05-25 13:40:56 +0200 | [diff] [blame] | 7 | #include <linux/wait.h> |
Eric Lescouet | 27729aa | 2010-04-24 23:21:52 +0200 | [diff] [blame] | 8 | #include <linux/usb/hcd.h> |
Ming Lei | 10e232c | 2013-06-28 09:38:12 +0800 | [diff] [blame] | 9 | #include <linux/scatterlist.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 10 | |
| 11 | #define to_urb(d) container_of(d, struct urb, kref) |
| 12 | |
Oliver Neukum | 6a2839b | 2008-07-29 16:18:47 +0200 | [diff] [blame] | 13 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 14 | static void urb_destroy(struct kref *kref) |
| 15 | { |
| 16 | struct urb *urb = to_urb(kref); |
Oliver Neukum | 51a2f07 | 2007-05-25 13:40:56 +0200 | [diff] [blame] | 17 | |
Marcel Holtmann | 8b3b01c | 2007-06-13 08:02:11 +0200 | [diff] [blame] | 18 | if (urb->transfer_flags & URB_FREE_BUFFER) |
| 19 | kfree(urb->transfer_buffer); |
| 20 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 21 | kfree(urb); |
| 22 | } |
| 23 | |
| 24 | /** |
| 25 | * usb_init_urb - initializes a urb so that it can be used by a USB driver |
| 26 | * @urb: pointer to the urb to initialize |
| 27 | * |
| 28 | * Initializes a urb so that the USB subsystem can use it properly. |
| 29 | * |
| 30 | * If a urb is created with a call to usb_alloc_urb() it is not |
| 31 | * necessary to call this function. Only use this if you allocate the |
| 32 | * space for a struct urb on your own. If you call this function, be |
| 33 | * careful when freeing the memory for your urb that it is no longer in |
| 34 | * use by the USB core. |
| 35 | * |
| 36 | * Only use this function if you _really_ understand what you are doing. |
| 37 | */ |
| 38 | void usb_init_urb(struct urb *urb) |
| 39 | { |
| 40 | if (urb) { |
| 41 | memset(urb, 0, sizeof(*urb)); |
| 42 | kref_init(&urb->kref); |
Oliver Neukum | 51a2f07 | 2007-05-25 13:40:56 +0200 | [diff] [blame] | 43 | INIT_LIST_HEAD(&urb->anchor_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | } |
| 45 | } |
Greg Kroah-Hartman | 782e70c | 2008-01-25 11:12:21 -0600 | [diff] [blame] | 46 | EXPORT_SYMBOL_GPL(usb_init_urb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 47 | |
| 48 | /** |
| 49 | * usb_alloc_urb - creates a new urb for a USB driver to use |
| 50 | * @iso_packets: number of iso packets for this urb |
| 51 | * @mem_flags: the type of memory to allocate, see kmalloc() for a list of |
| 52 | * valid options for this. |
| 53 | * |
| 54 | * Creates an urb for the USB driver to use, initializes a few internal |
Rahul Bedarkar | 025d443 | 2014-01-04 11:24:41 +0530 | [diff] [blame] | 55 | * structures, increments the usage counter, and returns a pointer to it. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 57 | * If the driver want to use this urb for interrupt, control, or bulk |
| 58 | * endpoints, pass '0' as the number of iso packets. |
| 59 | * |
| 60 | * The driver must call usb_free_urb() when it is finished with the urb. |
Yacine Belkadi | 626f090 | 2013-08-02 20:10:04 +0200 | [diff] [blame] | 61 | * |
| 62 | * Return: A pointer to the new urb, or %NULL if no memory is available. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 63 | */ |
Al Viro | 55016f1 | 2005-10-21 03:21:58 -0400 | [diff] [blame] | 64 | struct urb *usb_alloc_urb(int iso_packets, gfp_t mem_flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 65 | { |
| 66 | struct urb *urb; |
| 67 | |
Tobias Klauser | ec17cf1 | 2006-09-13 21:38:41 +0200 | [diff] [blame] | 68 | urb = kmalloc(sizeof(struct urb) + |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 69 | iso_packets * sizeof(struct usb_iso_packet_descriptor), |
| 70 | mem_flags); |
| 71 | if (!urb) { |
Greg Kroah-Hartman | 69a8594 | 2008-08-14 09:37:34 -0700 | [diff] [blame] | 72 | printk(KERN_ERR "alloc_urb: kmalloc failed\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 73 | return NULL; |
| 74 | } |
| 75 | usb_init_urb(urb); |
| 76 | return urb; |
| 77 | } |
Greg Kroah-Hartman | 782e70c | 2008-01-25 11:12:21 -0600 | [diff] [blame] | 78 | EXPORT_SYMBOL_GPL(usb_alloc_urb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 79 | |
| 80 | /** |
| 81 | * usb_free_urb - frees the memory used by a urb when all users of it are finished |
| 82 | * @urb: pointer to the urb to free, may be NULL |
| 83 | * |
| 84 | * Must be called when a user of a urb is finished with it. When the last user |
| 85 | * of the urb calls this function, the memory of the urb is freed. |
| 86 | * |
Rabin Vincent | 2870fde | 2008-11-09 11:40:30 +0530 | [diff] [blame] | 87 | * Note: The transfer buffer associated with the urb is not freed unless the |
| 88 | * URB_FREE_BUFFER transfer flag is set. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | */ |
| 90 | void usb_free_urb(struct urb *urb) |
| 91 | { |
| 92 | if (urb) |
| 93 | kref_put(&urb->kref, urb_destroy); |
| 94 | } |
Greg Kroah-Hartman | 782e70c | 2008-01-25 11:12:21 -0600 | [diff] [blame] | 95 | EXPORT_SYMBOL_GPL(usb_free_urb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 96 | |
| 97 | /** |
| 98 | * usb_get_urb - increments the reference count of the urb |
| 99 | * @urb: pointer to the urb to modify, may be NULL |
| 100 | * |
| 101 | * This must be called whenever a urb is transferred from a device driver to a |
| 102 | * host controller driver. This allows proper reference counting to happen |
| 103 | * for urbs. |
| 104 | * |
Yacine Belkadi | 626f090 | 2013-08-02 20:10:04 +0200 | [diff] [blame] | 105 | * Return: A pointer to the urb with the incremented reference counter. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 106 | */ |
Greg Kroah-Hartman | 2c044a4 | 2008-01-30 15:21:33 -0800 | [diff] [blame] | 107 | struct urb *usb_get_urb(struct urb *urb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 108 | { |
| 109 | if (urb) |
| 110 | kref_get(&urb->kref); |
| 111 | return urb; |
| 112 | } |
Greg Kroah-Hartman | 782e70c | 2008-01-25 11:12:21 -0600 | [diff] [blame] | 113 | EXPORT_SYMBOL_GPL(usb_get_urb); |
Oliver Neukum | 51a2f07 | 2007-05-25 13:40:56 +0200 | [diff] [blame] | 114 | |
| 115 | /** |
| 116 | * usb_anchor_urb - anchors an URB while it is processed |
| 117 | * @urb: pointer to the urb to anchor |
| 118 | * @anchor: pointer to the anchor |
| 119 | * |
| 120 | * This can be called to have access to URBs which are to be executed |
| 121 | * without bothering to track them |
| 122 | */ |
| 123 | void usb_anchor_urb(struct urb *urb, struct usb_anchor *anchor) |
| 124 | { |
| 125 | unsigned long flags; |
| 126 | |
| 127 | spin_lock_irqsave(&anchor->lock, flags); |
| 128 | usb_get_urb(urb); |
| 129 | list_add_tail(&urb->anchor_list, &anchor->urb_list); |
| 130 | urb->anchor = anchor; |
Oliver Neukum | 6a2839b | 2008-07-29 16:18:47 +0200 | [diff] [blame] | 131 | |
Jonas Hesselmann | ae416ba4 | 2015-10-25 19:28:58 +0100 | [diff] [blame] | 132 | if (unlikely(anchor->poisoned)) |
Ming Lei | 49367d8 | 2008-12-12 21:38:45 +0800 | [diff] [blame] | 133 | atomic_inc(&urb->reject); |
Oliver Neukum | 6a2839b | 2008-07-29 16:18:47 +0200 | [diff] [blame] | 134 | |
Oliver Neukum | 51a2f07 | 2007-05-25 13:40:56 +0200 | [diff] [blame] | 135 | spin_unlock_irqrestore(&anchor->lock, flags); |
| 136 | } |
| 137 | EXPORT_SYMBOL_GPL(usb_anchor_urb); |
| 138 | |
Hans de Goede | 6ec4147 | 2013-10-09 17:01:41 +0200 | [diff] [blame] | 139 | static int usb_anchor_check_wakeup(struct usb_anchor *anchor) |
| 140 | { |
| 141 | return atomic_read(&anchor->suspend_wakeups) == 0 && |
| 142 | list_empty(&anchor->urb_list); |
| 143 | } |
| 144 | |
Christian Lamparter | b3e6704 | 2010-08-03 02:32:28 +0200 | [diff] [blame] | 145 | /* Callers must hold anchor->lock */ |
| 146 | static void __usb_unanchor_urb(struct urb *urb, struct usb_anchor *anchor) |
| 147 | { |
| 148 | urb->anchor = NULL; |
| 149 | list_del(&urb->anchor_list); |
| 150 | usb_put_urb(urb); |
Hans de Goede | 6ec4147 | 2013-10-09 17:01:41 +0200 | [diff] [blame] | 151 | if (usb_anchor_check_wakeup(anchor)) |
Christian Lamparter | b3e6704 | 2010-08-03 02:32:28 +0200 | [diff] [blame] | 152 | wake_up(&anchor->wait); |
| 153 | } |
| 154 | |
Oliver Neukum | 51a2f07 | 2007-05-25 13:40:56 +0200 | [diff] [blame] | 155 | /** |
| 156 | * usb_unanchor_urb - unanchors an URB |
| 157 | * @urb: pointer to the urb to anchor |
| 158 | * |
| 159 | * Call this to stop the system keeping track of this URB |
| 160 | */ |
| 161 | void usb_unanchor_urb(struct urb *urb) |
| 162 | { |
| 163 | unsigned long flags; |
| 164 | struct usb_anchor *anchor; |
| 165 | |
| 166 | if (!urb) |
| 167 | return; |
| 168 | |
| 169 | anchor = urb->anchor; |
| 170 | if (!anchor) |
| 171 | return; |
| 172 | |
| 173 | spin_lock_irqsave(&anchor->lock, flags); |
Christian Lamparter | b3e6704 | 2010-08-03 02:32:28 +0200 | [diff] [blame] | 174 | /* |
| 175 | * At this point, we could be competing with another thread which |
| 176 | * has the same intention. To protect the urb from being unanchored |
| 177 | * twice, only the winner of the race gets the job. |
| 178 | */ |
| 179 | if (likely(anchor == urb->anchor)) |
| 180 | __usb_unanchor_urb(urb, anchor); |
Oliver Neukum | 51a2f07 | 2007-05-25 13:40:56 +0200 | [diff] [blame] | 181 | spin_unlock_irqrestore(&anchor->lock, flags); |
Oliver Neukum | 51a2f07 | 2007-05-25 13:40:56 +0200 | [diff] [blame] | 182 | } |
| 183 | EXPORT_SYMBOL_GPL(usb_unanchor_urb); |
| 184 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 185 | /*-------------------------------------------------------------------*/ |
| 186 | |
| 187 | /** |
| 188 | * usb_submit_urb - issue an asynchronous transfer request for an endpoint |
| 189 | * @urb: pointer to the urb describing the request |
| 190 | * @mem_flags: the type of memory to allocate, see kmalloc() for a list |
| 191 | * of valid options for this. |
| 192 | * |
| 193 | * This submits a transfer request, and transfers control of the URB |
| 194 | * describing that request to the USB subsystem. Request completion will |
| 195 | * be indicated later, asynchronously, by calling the completion handler. |
| 196 | * The three types of completion are success, error, and unlink |
Greg Kroah-Hartman | 2c044a4 | 2008-01-30 15:21:33 -0800 | [diff] [blame] | 197 | * (a software-induced fault, also called "request cancellation"). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 198 | * |
| 199 | * URBs may be submitted in interrupt context. |
| 200 | * |
| 201 | * The caller must have correctly initialized the URB before submitting |
| 202 | * it. Functions such as usb_fill_bulk_urb() and usb_fill_control_urb() are |
| 203 | * available to ensure that most fields are correctly initialized, for |
| 204 | * the particular kind of transfer, although they will not initialize |
| 205 | * any transfer flags. |
| 206 | * |
Yacine Belkadi | 626f090 | 2013-08-02 20:10:04 +0200 | [diff] [blame] | 207 | * If the submission is successful, the complete() callback from the URB |
| 208 | * will be called exactly once, when the USB core and Host Controller Driver |
| 209 | * (HCD) are finished with the URB. When the completion function is called, |
| 210 | * control of the URB is returned to the device driver which issued the |
| 211 | * request. The completion handler may then immediately free or reuse that |
| 212 | * URB. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 213 | * |
| 214 | * With few exceptions, USB device drivers should never access URB fields |
| 215 | * provided by usbcore or the HCD until its complete() is called. |
| 216 | * The exceptions relate to periodic transfer scheduling. For both |
| 217 | * interrupt and isochronous urbs, as part of successful URB submission |
| 218 | * urb->interval is modified to reflect the actual transfer period used |
| 219 | * (normally some power of two units). And for isochronous urbs, |
| 220 | * urb->start_frame is modified to reflect when the URB's transfers were |
Alan Stern | a03bede | 2012-10-01 10:31:53 -0400 | [diff] [blame] | 221 | * scheduled to start. |
| 222 | * |
| 223 | * Not all isochronous transfer scheduling policies will work, but most |
| 224 | * host controller drivers should easily handle ISO queues going from now |
| 225 | * until 10-200 msec into the future. Drivers should try to keep at |
| 226 | * least one or two msec of data in the queue; many controllers require |
| 227 | * that new transfers start at least 1 msec in the future when they are |
| 228 | * added. If the driver is unable to keep up and the queue empties out, |
| 229 | * the behavior for new submissions is governed by the URB_ISO_ASAP flag. |
| 230 | * If the flag is set, or if the queue is idle, then the URB is always |
| 231 | * assigned to the first available (and not yet expired) slot in the |
| 232 | * endpoint's schedule. If the flag is not set and the queue is active |
| 233 | * then the URB is always assigned to the next slot in the schedule |
| 234 | * following the end of the endpoint's previous URB, even if that slot is |
| 235 | * in the past. When a packet is assigned in this way to a slot that has |
| 236 | * already expired, the packet is not transmitted and the corresponding |
| 237 | * usb_iso_packet_descriptor's status field will return -EXDEV. If this |
| 238 | * would happen to all the packets in the URB, submission fails with a |
| 239 | * -EXDEV error code. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 240 | * |
| 241 | * For control endpoints, the synchronous usb_control_msg() call is |
| 242 | * often used (in non-interrupt context) instead of this call. |
| 243 | * That is often used through convenience wrappers, for the requests |
| 244 | * that are standardized in the USB 2.0 specification. For bulk |
| 245 | * endpoints, a synchronous usb_bulk_msg() call is available. |
| 246 | * |
Yacine Belkadi | 626f090 | 2013-08-02 20:10:04 +0200 | [diff] [blame] | 247 | * Return: |
| 248 | * 0 on successful submissions. A negative error number otherwise. |
| 249 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 250 | * Request Queuing: |
| 251 | * |
| 252 | * URBs may be submitted to endpoints before previous ones complete, to |
| 253 | * minimize the impact of interrupt latencies and system overhead on data |
| 254 | * throughput. With that queuing policy, an endpoint's queue would never |
| 255 | * be empty. This is required for continuous isochronous data streams, |
| 256 | * and may also be required for some kinds of interrupt transfers. Such |
| 257 | * queuing also maximizes bandwidth utilization by letting USB controllers |
| 258 | * start work on later requests before driver software has finished the |
| 259 | * completion processing for earlier (successful) requests. |
| 260 | * |
| 261 | * As of Linux 2.6, all USB endpoint transfer queues support depths greater |
| 262 | * than one. This was previously a HCD-specific behavior, except for ISO |
| 263 | * transfers. Non-isochronous endpoint queues are inactive during cleanup |
Steven Cole | 093cf72 | 2005-05-03 19:07:24 -0600 | [diff] [blame] | 264 | * after faults (transfer errors or cancellation). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 265 | * |
| 266 | * Reserved Bandwidth Transfers: |
| 267 | * |
| 268 | * Periodic transfers (interrupt or isochronous) are performed repeatedly, |
| 269 | * using the interval specified in the urb. Submitting the first urb to |
| 270 | * the endpoint reserves the bandwidth necessary to make those transfers. |
| 271 | * If the USB subsystem can't allocate sufficient bandwidth to perform |
| 272 | * the periodic request, submitting such a periodic request should fail. |
| 273 | * |
Sarah Sharp | 79abb1a | 2009-04-27 19:58:26 -0700 | [diff] [blame] | 274 | * For devices under xHCI, the bandwidth is reserved at configuration time, or |
| 275 | * when the alt setting is selected. If there is not enough bus bandwidth, the |
| 276 | * configuration/alt setting request will fail. Therefore, submissions to |
| 277 | * periodic endpoints on devices under xHCI should never fail due to bandwidth |
| 278 | * constraints. |
| 279 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 280 | * Device drivers must explicitly request that repetition, by ensuring that |
| 281 | * some URB is always on the endpoint's queue (except possibly for short |
Rahul Bedarkar | 025d443 | 2014-01-04 11:24:41 +0530 | [diff] [blame] | 282 | * periods during completion callbacks). When there is no longer an urb |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 283 | * queued, the endpoint's bandwidth reservation is canceled. This means |
| 284 | * drivers can use their completion handlers to ensure they keep bandwidth |
| 285 | * they need, by reinitializing and resubmitting the just-completed urb |
| 286 | * until the driver longer needs that periodic bandwidth. |
| 287 | * |
| 288 | * Memory Flags: |
| 289 | * |
| 290 | * The general rules for how to decide which mem_flags to use |
| 291 | * are the same as for kmalloc. There are four |
| 292 | * different possible values; GFP_KERNEL, GFP_NOFS, GFP_NOIO and |
| 293 | * GFP_ATOMIC. |
| 294 | * |
| 295 | * GFP_NOFS is not ever used, as it has not been implemented yet. |
| 296 | * |
| 297 | * GFP_ATOMIC is used when |
| 298 | * (a) you are inside a completion handler, an interrupt, bottom half, |
| 299 | * tasklet or timer, or |
| 300 | * (b) you are holding a spinlock or rwlock (does not apply to |
| 301 | * semaphores), or |
| 302 | * (c) current->state != TASK_RUNNING, this is the case only after |
| 303 | * you've changed it. |
Greg Kroah-Hartman | 2c044a4 | 2008-01-30 15:21:33 -0800 | [diff] [blame] | 304 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 305 | * GFP_NOIO is used in the block io path and error handling of storage |
| 306 | * devices. |
| 307 | * |
| 308 | * All other situations use GFP_KERNEL. |
| 309 | * |
| 310 | * Some more specific rules for mem_flags can be inferred, such as |
| 311 | * (1) start_xmit, timeout, and receive methods of network drivers must |
| 312 | * use GFP_ATOMIC (they are called with a spinlock held); |
| 313 | * (2) queuecommand methods of scsi drivers must use GFP_ATOMIC (also |
| 314 | * called with a spinlock held); |
| 315 | * (3) If you use a kernel thread with a network driver you must use |
| 316 | * GFP_NOIO, unless (b) or (c) apply; |
| 317 | * (4) after you have done a down() you can use GFP_KERNEL, unless (b) or (c) |
| 318 | * apply or your are in a storage driver's block io path; |
| 319 | * (5) USB probe and disconnect can use GFP_KERNEL unless (b) or (c) apply; and |
| 320 | * (6) changing firmware on a running storage or net device uses |
| 321 | * GFP_NOIO, unless b) or c) apply |
| 322 | * |
| 323 | */ |
Al Viro | 55016f1 | 2005-10-21 03:21:58 -0400 | [diff] [blame] | 324 | int usb_submit_urb(struct urb *urb, gfp_t mem_flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 325 | { |
Greg Kroah-Hartman | 3482528 | 2013-12-19 15:42:20 -0800 | [diff] [blame] | 326 | static int pipetypes[4] = { |
| 327 | PIPE_CONTROL, PIPE_ISOCHRONOUS, PIPE_BULK, PIPE_INTERRUPT |
| 328 | }; |
Alan Stern | 5b653c7 | 2007-07-30 17:04:37 -0400 | [diff] [blame] | 329 | int xfertype, max; |
| 330 | struct usb_device *dev; |
| 331 | struct usb_host_endpoint *ep; |
| 332 | int is_out; |
Greg Kroah-Hartman | 3482528 | 2013-12-19 15:42:20 -0800 | [diff] [blame] | 333 | unsigned int allowed; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 334 | |
Alan Stern | 2f02bc8 | 2012-11-07 16:35:00 -0500 | [diff] [blame] | 335 | if (!urb || !urb->complete) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 336 | return -EINVAL; |
Alan Stern | 2f02bc8 | 2012-11-07 16:35:00 -0500 | [diff] [blame] | 337 | if (urb->hcpriv) { |
| 338 | WARN_ONCE(1, "URB %p submitted while active\n", urb); |
| 339 | return -EBUSY; |
| 340 | } |
| 341 | |
Greg Kroah-Hartman | 2c044a4 | 2008-01-30 15:21:33 -0800 | [diff] [blame] | 342 | dev = urb->dev; |
David Vrabel | 6da9c99 | 2009-02-18 14:43:47 +0000 | [diff] [blame] | 343 | if ((!dev) || (dev->state < USB_STATE_UNAUTHENTICATED)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 344 | return -ENODEV; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 345 | |
Alan Stern | 5b653c7 | 2007-07-30 17:04:37 -0400 | [diff] [blame] | 346 | /* For now, get the endpoint from the pipe. Eventually drivers |
| 347 | * will be required to set urb->ep directly and we will eliminate |
| 348 | * urb->pipe. |
| 349 | */ |
Matthew Wilcox | fe54b05 | 2010-04-30 13:11:29 -0600 | [diff] [blame] | 350 | ep = usb_pipe_endpoint(dev, urb->pipe); |
Alan Stern | 5b653c7 | 2007-07-30 17:04:37 -0400 | [diff] [blame] | 351 | if (!ep) |
| 352 | return -ENOENT; |
| 353 | |
| 354 | urb->ep = ep; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 355 | urb->status = -EINPROGRESS; |
| 356 | urb->actual_length = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 357 | |
| 358 | /* Lots of sanity checks, so HCDs can rely on clean data |
| 359 | * and don't need to duplicate tests |
| 360 | */ |
Alan Stern | 5b653c7 | 2007-07-30 17:04:37 -0400 | [diff] [blame] | 361 | xfertype = usb_endpoint_type(&ep->desc); |
Alan Stern | fea3409 | 2007-07-30 17:06:16 -0400 | [diff] [blame] | 362 | if (xfertype == USB_ENDPOINT_XFER_CONTROL) { |
| 363 | struct usb_ctrlrequest *setup = |
| 364 | (struct usb_ctrlrequest *) urb->setup_packet; |
| 365 | |
| 366 | if (!setup) |
| 367 | return -ENOEXEC; |
| 368 | is_out = !(setup->bRequestType & USB_DIR_IN) || |
| 369 | !setup->wLength; |
| 370 | } else { |
| 371 | is_out = usb_endpoint_dir_out(&ep->desc); |
| 372 | } |
| 373 | |
Alan Stern | ff9c895 | 2010-04-02 13:27:28 -0400 | [diff] [blame] | 374 | /* Clear the internal flags and cache the direction for later use */ |
| 375 | urb->transfer_flags &= ~(URB_DIR_MASK | URB_DMA_MAP_SINGLE | |
| 376 | URB_DMA_MAP_PAGE | URB_DMA_MAP_SG | URB_MAP_LOCAL | |
| 377 | URB_SETUP_MAP_SINGLE | URB_SETUP_MAP_LOCAL | |
| 378 | URB_DMA_SG_COMBINED); |
| 379 | urb->transfer_flags |= (is_out ? URB_DIR_OUT : URB_DIR_IN); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 380 | |
Alan Stern | 5b653c7 | 2007-07-30 17:04:37 -0400 | [diff] [blame] | 381 | if (xfertype != USB_ENDPOINT_XFER_CONTROL && |
| 382 | dev->state < USB_STATE_CONFIGURED) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 383 | return -ENODEV; |
| 384 | |
Kuninori Morimoto | 29cc889 | 2011-08-23 03:12:03 -0700 | [diff] [blame] | 385 | max = usb_endpoint_maxp(&ep->desc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 386 | if (max <= 0) { |
| 387 | dev_dbg(&dev->dev, |
| 388 | "bogus endpoint ep%d%s in %s (bad maxpacket %d)\n", |
Alan Stern | 5b653c7 | 2007-07-30 17:04:37 -0400 | [diff] [blame] | 389 | usb_endpoint_num(&ep->desc), is_out ? "out" : "in", |
Harvey Harrison | 441b62c | 2008-03-03 16:08:34 -0800 | [diff] [blame] | 390 | __func__, max); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 391 | return -EMSGSIZE; |
| 392 | } |
| 393 | |
| 394 | /* periodic transfers limit size per frame/uframe, |
| 395 | * but drivers only control those sizes for ISO. |
| 396 | * while we're checking, initialize return status. |
| 397 | */ |
Alan Stern | 5b653c7 | 2007-07-30 17:04:37 -0400 | [diff] [blame] | 398 | if (xfertype == USB_ENDPOINT_XFER_ISOC) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 399 | int n, len; |
| 400 | |
Paul Zimmerman | 500132a | 2011-02-28 18:11:27 -0800 | [diff] [blame] | 401 | /* SuperSpeed isoc endpoints have up to 16 bursts of up to |
| 402 | * 3 packets each |
| 403 | */ |
| 404 | if (dev->speed == USB_SPEED_SUPER) { |
| 405 | int burst = 1 + ep->ss_ep_comp.bMaxBurst; |
| 406 | int mult = USB_SS_MULT(ep->ss_ep_comp.bmAttributes); |
| 407 | max *= burst; |
| 408 | max *= mult; |
| 409 | } |
| 410 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 411 | /* "high bandwidth" mode, 1-3 packets/uframe? */ |
| 412 | if (dev->speed == USB_SPEED_HIGH) { |
| 413 | int mult = 1 + ((max >> 11) & 0x03); |
| 414 | max &= 0x07ff; |
| 415 | max *= mult; |
| 416 | } |
| 417 | |
Greg Kroah-Hartman | 2c044a4 | 2008-01-30 15:21:33 -0800 | [diff] [blame] | 418 | if (urb->number_of_packets <= 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 419 | return -EINVAL; |
| 420 | for (n = 0; n < urb->number_of_packets; n++) { |
Oliver Neukum | 9251644 | 2007-01-23 15:55:28 -0500 | [diff] [blame] | 421 | len = urb->iso_frame_desc[n].length; |
Greg Kroah-Hartman | 2c044a4 | 2008-01-30 15:21:33 -0800 | [diff] [blame] | 422 | if (len < 0 || len > max) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 423 | return -EMSGSIZE; |
Oliver Neukum | 9251644 | 2007-01-23 15:55:28 -0500 | [diff] [blame] | 424 | urb->iso_frame_desc[n].status = -EXDEV; |
| 425 | urb->iso_frame_desc[n].actual_length = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 426 | } |
Ming Lei | bcc48f1 | 2013-08-08 21:48:22 +0800 | [diff] [blame] | 427 | } else if (urb->num_sgs && !urb->dev->bus->no_sg_constraint && |
| 428 | dev->speed != USB_SPEED_WIRELESS) { |
Ming Lei | 10e232c | 2013-06-28 09:38:12 +0800 | [diff] [blame] | 429 | struct scatterlist *sg; |
| 430 | int i; |
| 431 | |
| 432 | for_each_sg(urb->sg, sg, urb->num_sgs - 1, i) |
| 433 | if (sg->length % max) |
| 434 | return -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 435 | } |
| 436 | |
| 437 | /* the I/O buffer must be mapped/unmapped, except when length=0 */ |
Roel Kluin | 71d2718 | 2009-03-13 12:19:18 +0100 | [diff] [blame] | 438 | if (urb->transfer_buffer_length > INT_MAX) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 439 | return -EMSGSIZE; |
| 440 | |
Greg Kroah-Hartman | 3482528 | 2013-12-19 15:42:20 -0800 | [diff] [blame] | 441 | /* |
| 442 | * stuff that drivers shouldn't do, but which shouldn't |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 443 | * cause problems in HCDs if they get it wrong. |
| 444 | */ |
Alan Stern | f661c6f | 2009-12-11 16:20:20 -0500 | [diff] [blame] | 445 | |
| 446 | /* Check that the pipe's type matches the endpoint's type */ |
Alan Stern | 0cb54a3 | 2012-02-02 15:38:14 -0500 | [diff] [blame] | 447 | if (usb_pipetype(urb->pipe) != pipetypes[xfertype]) |
| 448 | dev_WARN(&dev->dev, "BOGUS urb xfer, pipe %x != type %x\n", |
Simon Arlott | f7dd649 | 2010-08-30 22:50:20 +0100 | [diff] [blame] | 449 | usb_pipetype(urb->pipe), pipetypes[xfertype]); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 450 | |
Alan Stern | 0cb54a3 | 2012-02-02 15:38:14 -0500 | [diff] [blame] | 451 | /* Check against a simple/standard policy */ |
Alan Stern | 0ede76f | 2010-03-05 15:10:17 -0500 | [diff] [blame] | 452 | allowed = (URB_NO_TRANSFER_DMA_MAP | URB_NO_INTERRUPT | URB_DIR_MASK | |
| 453 | URB_FREE_BUFFER); |
Alan Stern | 5b653c7 | 2007-07-30 17:04:37 -0400 | [diff] [blame] | 454 | switch (xfertype) { |
| 455 | case USB_ENDPOINT_XFER_BULK: |
Amit Virdi | 9672f0f | 2014-07-21 10:46:18 +0530 | [diff] [blame] | 456 | case USB_ENDPOINT_XFER_INT: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 457 | if (is_out) |
| 458 | allowed |= URB_ZERO_PACKET; |
| 459 | /* FALLTHROUGH */ |
Alan Stern | 5b653c7 | 2007-07-30 17:04:37 -0400 | [diff] [blame] | 460 | case USB_ENDPOINT_XFER_CONTROL: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 461 | allowed |= URB_NO_FSBR; /* only affects UHCI */ |
| 462 | /* FALLTHROUGH */ |
| 463 | default: /* all non-iso endpoints */ |
| 464 | if (!is_out) |
| 465 | allowed |= URB_SHORT_NOT_OK; |
| 466 | break; |
Alan Stern | 5b653c7 | 2007-07-30 17:04:37 -0400 | [diff] [blame] | 467 | case USB_ENDPOINT_XFER_ISOC: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 468 | allowed |= URB_ISO_ASAP; |
| 469 | break; |
| 470 | } |
Alan Stern | 0cb54a3 | 2012-02-02 15:38:14 -0500 | [diff] [blame] | 471 | allowed &= urb->transfer_flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 472 | |
Alan Stern | 0cb54a3 | 2012-02-02 15:38:14 -0500 | [diff] [blame] | 473 | /* warn if submitter gave bogus flags */ |
| 474 | if (allowed != urb->transfer_flags) |
| 475 | dev_WARN(&dev->dev, "BOGUS urb flags, %x --> %x\n", |
| 476 | urb->transfer_flags, allowed); |
Greg Kroah-Hartman | 3482528 | 2013-12-19 15:42:20 -0800 | [diff] [blame] | 477 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 478 | /* |
| 479 | * Force periodic transfer intervals to be legal values that are |
| 480 | * a power of two (so HCDs don't need to). |
| 481 | * |
| 482 | * FIXME want bus->{intr,iso}_sched_horizon values here. Each HC |
| 483 | * supports different values... this uses EHCI/UHCI defaults (and |
| 484 | * EHCI can use smaller non-default values). |
| 485 | */ |
Alan Stern | 5b653c7 | 2007-07-30 17:04:37 -0400 | [diff] [blame] | 486 | switch (xfertype) { |
| 487 | case USB_ENDPOINT_XFER_ISOC: |
| 488 | case USB_ENDPOINT_XFER_INT: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 489 | /* too small? */ |
David Vrabel | 8e08b97 | 2009-08-18 16:11:24 +0100 | [diff] [blame] | 490 | switch (dev->speed) { |
Greg Kroah-Hartman | 551cdbb | 2010-01-14 11:08:04 -0800 | [diff] [blame] | 491 | case USB_SPEED_WIRELESS: |
Thomas Pugliese | a2cd612 | 2013-12-09 13:45:43 -0600 | [diff] [blame] | 492 | if ((urb->interval < 6) |
| 493 | && (xfertype == USB_ENDPOINT_XFER_INT)) |
David Vrabel | 8e08b97 | 2009-08-18 16:11:24 +0100 | [diff] [blame] | 494 | return -EINVAL; |
David Vrabel | 8e08b97 | 2009-08-18 16:11:24 +0100 | [diff] [blame] | 495 | default: |
| 496 | if (urb->interval <= 0) |
| 497 | return -EINVAL; |
| 498 | break; |
| 499 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 500 | /* too big? */ |
| 501 | switch (dev->speed) { |
Sarah Sharp | 6b403b0 | 2009-04-27 19:54:10 -0700 | [diff] [blame] | 502 | case USB_SPEED_SUPER: /* units are 125us */ |
| 503 | /* Handle up to 2^(16-1) microframes */ |
| 504 | if (urb->interval > (1 << 15)) |
| 505 | return -EINVAL; |
| 506 | max = 1 << 15; |
Matthew Wilcox | f09a15e | 2010-03-16 12:55:44 -0700 | [diff] [blame] | 507 | break; |
Greg Kroah-Hartman | 551cdbb | 2010-01-14 11:08:04 -0800 | [diff] [blame] | 508 | case USB_SPEED_WIRELESS: |
David Vrabel | 8e08b97 | 2009-08-18 16:11:24 +0100 | [diff] [blame] | 509 | if (urb->interval > 16) |
| 510 | return -EINVAL; |
| 511 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 512 | case USB_SPEED_HIGH: /* units are microframes */ |
Greg Kroah-Hartman | 2c044a4 | 2008-01-30 15:21:33 -0800 | [diff] [blame] | 513 | /* NOTE usb handles 2^15 */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 514 | if (urb->interval > (1024 * 8)) |
| 515 | urb->interval = 1024 * 8; |
Alan Stern | 5b653c7 | 2007-07-30 17:04:37 -0400 | [diff] [blame] | 516 | max = 1024 * 8; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 517 | break; |
| 518 | case USB_SPEED_FULL: /* units are frames/msec */ |
| 519 | case USB_SPEED_LOW: |
Alan Stern | 5b653c7 | 2007-07-30 17:04:37 -0400 | [diff] [blame] | 520 | if (xfertype == USB_ENDPOINT_XFER_INT) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 521 | if (urb->interval > 255) |
| 522 | return -EINVAL; |
Greg Kroah-Hartman | 2c044a4 | 2008-01-30 15:21:33 -0800 | [diff] [blame] | 523 | /* NOTE ohci only handles up to 32 */ |
Alan Stern | 5b653c7 | 2007-07-30 17:04:37 -0400 | [diff] [blame] | 524 | max = 128; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 525 | } else { |
| 526 | if (urb->interval > 1024) |
| 527 | urb->interval = 1024; |
Greg Kroah-Hartman | 2c044a4 | 2008-01-30 15:21:33 -0800 | [diff] [blame] | 528 | /* NOTE usb and ohci handle up to 2^15 */ |
Alan Stern | 5b653c7 | 2007-07-30 17:04:37 -0400 | [diff] [blame] | 529 | max = 1024; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 530 | } |
| 531 | break; |
| 532 | default: |
| 533 | return -EINVAL; |
| 534 | } |
Greg Kroah-Hartman | 551cdbb | 2010-01-14 11:08:04 -0800 | [diff] [blame] | 535 | if (dev->speed != USB_SPEED_WIRELESS) { |
David Vrabel | 8e08b97 | 2009-08-18 16:11:24 +0100 | [diff] [blame] | 536 | /* Round down to a power of 2, no more than max */ |
| 537 | urb->interval = min(max, 1 << ilog2(urb->interval)); |
| 538 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 539 | } |
| 540 | |
Oliver Neukum | 9251644 | 2007-01-23 15:55:28 -0500 | [diff] [blame] | 541 | return usb_hcd_submit_urb(urb, mem_flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 542 | } |
Greg Kroah-Hartman | 782e70c | 2008-01-25 11:12:21 -0600 | [diff] [blame] | 543 | EXPORT_SYMBOL_GPL(usb_submit_urb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 544 | |
| 545 | /*-------------------------------------------------------------------*/ |
| 546 | |
| 547 | /** |
| 548 | * usb_unlink_urb - abort/cancel a transfer request for an endpoint |
| 549 | * @urb: pointer to urb describing a previously submitted request, |
| 550 | * may be NULL |
| 551 | * |
Alan Stern | beafef0 | 2007-07-13 15:47:16 -0400 | [diff] [blame] | 552 | * This routine cancels an in-progress request. URBs complete only once |
| 553 | * per submission, and may be canceled only once per submission. |
| 554 | * Successful cancellation means termination of @urb will be expedited |
| 555 | * and the completion handler will be called with a status code |
| 556 | * indicating that the request has been canceled (rather than any other |
| 557 | * code). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 558 | * |
Alan Stern | cde217a | 2008-10-21 15:28:46 -0400 | [diff] [blame] | 559 | * Drivers should not call this routine or related routines, such as |
| 560 | * usb_kill_urb() or usb_unlink_anchored_urbs(), after their disconnect |
| 561 | * method has returned. The disconnect function should synchronize with |
| 562 | * a driver's I/O routines to insure that all URB-related activity has |
| 563 | * completed before it returns. |
| 564 | * |
Sebastian Andrzej Siewior | 371f3b4 | 2012-02-29 23:04:32 +0100 | [diff] [blame] | 565 | * This request is asynchronous, however the HCD might call the ->complete() |
| 566 | * callback during unlink. Therefore when drivers call usb_unlink_urb(), they |
| 567 | * must not hold any locks that may be taken by the completion function. |
| 568 | * Success is indicated by returning -EINPROGRESS, at which time the URB will |
| 569 | * probably not yet have been given back to the device driver. When it is |
| 570 | * eventually called, the completion function will see @urb->status == |
| 571 | * -ECONNRESET. |
Alan Stern | beafef0 | 2007-07-13 15:47:16 -0400 | [diff] [blame] | 572 | * Failure is indicated by usb_unlink_urb() returning any other value. |
| 573 | * Unlinking will fail when @urb is not currently "linked" (i.e., it was |
| 574 | * never submitted, or it was unlinked before, or the hardware is already |
| 575 | * finished with it), even if the completion handler has not yet run. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 576 | * |
Alan Stern | da8bfb0 | 2012-03-28 16:13:28 -0400 | [diff] [blame] | 577 | * The URB must not be deallocated while this routine is running. In |
| 578 | * particular, when a driver calls this routine, it must insure that the |
| 579 | * completion handler cannot deallocate the URB. |
| 580 | * |
Yacine Belkadi | 626f090 | 2013-08-02 20:10:04 +0200 | [diff] [blame] | 581 | * Return: -EINPROGRESS on success. See description for other values on |
| 582 | * failure. |
| 583 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 584 | * Unlinking and Endpoint Queues: |
| 585 | * |
Alan Stern | beafef0 | 2007-07-13 15:47:16 -0400 | [diff] [blame] | 586 | * [The behaviors and guarantees described below do not apply to virtual |
| 587 | * root hubs but only to endpoint queues for physical USB devices.] |
| 588 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 589 | * Host Controller Drivers (HCDs) place all the URBs for a particular |
| 590 | * endpoint in a queue. Normally the queue advances as the controller |
Alan Stern | 8835f66 | 2005-04-18 17:39:30 -0700 | [diff] [blame] | 591 | * hardware processes each request. But when an URB terminates with an |
Alan Stern | beafef0 | 2007-07-13 15:47:16 -0400 | [diff] [blame] | 592 | * error its queue generally stops (see below), at least until that URB's |
| 593 | * completion routine returns. It is guaranteed that a stopped queue |
| 594 | * will not restart until all its unlinked URBs have been fully retired, |
| 595 | * with their completion routines run, even if that's not until some time |
| 596 | * after the original completion handler returns. The same behavior and |
| 597 | * guarantee apply when an URB terminates because it was unlinked. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 598 | * |
Alan Stern | beafef0 | 2007-07-13 15:47:16 -0400 | [diff] [blame] | 599 | * Bulk and interrupt endpoint queues are guaranteed to stop whenever an |
| 600 | * URB terminates with any sort of error, including -ECONNRESET, -ENOENT, |
| 601 | * and -EREMOTEIO. Control endpoint queues behave the same way except |
| 602 | * that they are not guaranteed to stop for -EREMOTEIO errors. Queues |
| 603 | * for isochronous endpoints are treated differently, because they must |
| 604 | * advance at fixed rates. Such queues do not stop when an URB |
| 605 | * encounters an error or is unlinked. An unlinked isochronous URB may |
| 606 | * leave a gap in the stream of packets; it is undefined whether such |
| 607 | * gaps can be filled in. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 608 | * |
Alan Stern | beafef0 | 2007-07-13 15:47:16 -0400 | [diff] [blame] | 609 | * Note that early termination of an URB because a short packet was |
| 610 | * received will generate a -EREMOTEIO error if and only if the |
| 611 | * URB_SHORT_NOT_OK flag is set. By setting this flag, USB device |
| 612 | * drivers can build deep queues for large or complex bulk transfers |
| 613 | * and clean them up reliably after any sort of aborted transfer by |
| 614 | * unlinking all pending URBs at the first fault. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 615 | * |
Alan Stern | beafef0 | 2007-07-13 15:47:16 -0400 | [diff] [blame] | 616 | * When a control URB terminates with an error other than -EREMOTEIO, it |
| 617 | * is quite likely that the status stage of the transfer will not take |
| 618 | * place. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 619 | */ |
| 620 | int usb_unlink_urb(struct urb *urb) |
| 621 | { |
| 622 | if (!urb) |
| 623 | return -EINVAL; |
Alan Stern | d617bc8 | 2007-08-02 15:04:52 -0400 | [diff] [blame] | 624 | if (!urb->dev) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 625 | return -ENODEV; |
Alan Stern | d617bc8 | 2007-08-02 15:04:52 -0400 | [diff] [blame] | 626 | if (!urb->ep) |
| 627 | return -EIDRM; |
Alan Stern | a6d2bb9 | 2006-08-30 11:27:36 -0400 | [diff] [blame] | 628 | return usb_hcd_unlink_urb(urb, -ECONNRESET); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 629 | } |
Greg Kroah-Hartman | 782e70c | 2008-01-25 11:12:21 -0600 | [diff] [blame] | 630 | EXPORT_SYMBOL_GPL(usb_unlink_urb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 631 | |
| 632 | /** |
| 633 | * usb_kill_urb - cancel a transfer request and wait for it to finish |
| 634 | * @urb: pointer to URB describing a previously submitted request, |
| 635 | * may be NULL |
| 636 | * |
| 637 | * This routine cancels an in-progress request. It is guaranteed that |
| 638 | * upon return all completion handlers will have finished and the URB |
| 639 | * will be totally idle and available for reuse. These features make |
| 640 | * this an ideal way to stop I/O in a disconnect() callback or close() |
| 641 | * function. If the request has not already finished or been unlinked |
| 642 | * the completion handler will see urb->status == -ENOENT. |
| 643 | * |
| 644 | * While the routine is running, attempts to resubmit the URB will fail |
| 645 | * with error -EPERM. Thus even if the URB's completion handler always |
| 646 | * tries to resubmit, it will not succeed and the URB will become idle. |
| 647 | * |
Alan Stern | da8bfb0 | 2012-03-28 16:13:28 -0400 | [diff] [blame] | 648 | * The URB must not be deallocated while this routine is running. In |
| 649 | * particular, when a driver calls this routine, it must insure that the |
| 650 | * completion handler cannot deallocate the URB. |
| 651 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 652 | * This routine may not be used in an interrupt context (such as a bottom |
| 653 | * half or a completion handler), or when holding a spinlock, or in other |
| 654 | * situations where the caller can't schedule(). |
Alan Stern | cde217a | 2008-10-21 15:28:46 -0400 | [diff] [blame] | 655 | * |
| 656 | * This routine should not be called by a driver after its disconnect |
| 657 | * method has returned. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 658 | */ |
| 659 | void usb_kill_urb(struct urb *urb) |
| 660 | { |
Greg Kroah-Hartman | e9aa795 | 2006-01-23 17:17:21 -0500 | [diff] [blame] | 661 | might_sleep(); |
Alan Stern | d617bc8 | 2007-08-02 15:04:52 -0400 | [diff] [blame] | 662 | if (!(urb && urb->dev && urb->ep)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 663 | return; |
Ming Lei | 49367d8 | 2008-12-12 21:38:45 +0800 | [diff] [blame] | 664 | atomic_inc(&urb->reject); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 665 | |
Alan Stern | a6d2bb9 | 2006-08-30 11:27:36 -0400 | [diff] [blame] | 666 | usb_hcd_unlink_urb(urb, -ENOENT); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 667 | wait_event(usb_kill_urb_queue, atomic_read(&urb->use_count) == 0); |
| 668 | |
Ming Lei | 49367d8 | 2008-12-12 21:38:45 +0800 | [diff] [blame] | 669 | atomic_dec(&urb->reject); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 670 | } |
Greg Kroah-Hartman | 782e70c | 2008-01-25 11:12:21 -0600 | [diff] [blame] | 671 | EXPORT_SYMBOL_GPL(usb_kill_urb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 672 | |
Oliver Neukum | 51a2f07 | 2007-05-25 13:40:56 +0200 | [diff] [blame] | 673 | /** |
Oliver Neukum | 55b447b | 2008-07-29 15:26:15 +0200 | [diff] [blame] | 674 | * usb_poison_urb - reliably kill a transfer and prevent further use of an URB |
| 675 | * @urb: pointer to URB describing a previously submitted request, |
| 676 | * may be NULL |
| 677 | * |
| 678 | * This routine cancels an in-progress request. It is guaranteed that |
| 679 | * upon return all completion handlers will have finished and the URB |
| 680 | * will be totally idle and cannot be reused. These features make |
| 681 | * this an ideal way to stop I/O in a disconnect() callback. |
| 682 | * If the request has not already finished or been unlinked |
| 683 | * the completion handler will see urb->status == -ENOENT. |
| 684 | * |
| 685 | * After and while the routine runs, attempts to resubmit the URB will fail |
| 686 | * with error -EPERM. Thus even if the URB's completion handler always |
| 687 | * tries to resubmit, it will not succeed and the URB will become idle. |
| 688 | * |
Alan Stern | da8bfb0 | 2012-03-28 16:13:28 -0400 | [diff] [blame] | 689 | * The URB must not be deallocated while this routine is running. In |
| 690 | * particular, when a driver calls this routine, it must insure that the |
| 691 | * completion handler cannot deallocate the URB. |
| 692 | * |
Oliver Neukum | 55b447b | 2008-07-29 15:26:15 +0200 | [diff] [blame] | 693 | * This routine may not be used in an interrupt context (such as a bottom |
| 694 | * half or a completion handler), or when holding a spinlock, or in other |
| 695 | * situations where the caller can't schedule(). |
Alan Stern | cde217a | 2008-10-21 15:28:46 -0400 | [diff] [blame] | 696 | * |
| 697 | * This routine should not be called by a driver after its disconnect |
| 698 | * method has returned. |
Oliver Neukum | 55b447b | 2008-07-29 15:26:15 +0200 | [diff] [blame] | 699 | */ |
| 700 | void usb_poison_urb(struct urb *urb) |
| 701 | { |
| 702 | might_sleep(); |
Johan Hovold | 68a2bed | 2013-03-21 12:36:48 +0100 | [diff] [blame] | 703 | if (!urb) |
Oliver Neukum | 55b447b | 2008-07-29 15:26:15 +0200 | [diff] [blame] | 704 | return; |
Ming Lei | 49367d8 | 2008-12-12 21:38:45 +0800 | [diff] [blame] | 705 | atomic_inc(&urb->reject); |
Oliver Neukum | 55b447b | 2008-07-29 15:26:15 +0200 | [diff] [blame] | 706 | |
Johan Hovold | 68a2bed | 2013-03-21 12:36:48 +0100 | [diff] [blame] | 707 | if (!urb->dev || !urb->ep) |
| 708 | return; |
| 709 | |
Oliver Neukum | 55b447b | 2008-07-29 15:26:15 +0200 | [diff] [blame] | 710 | usb_hcd_unlink_urb(urb, -ENOENT); |
| 711 | wait_event(usb_kill_urb_queue, atomic_read(&urb->use_count) == 0); |
| 712 | } |
| 713 | EXPORT_SYMBOL_GPL(usb_poison_urb); |
| 714 | |
| 715 | void usb_unpoison_urb(struct urb *urb) |
| 716 | { |
| 717 | if (!urb) |
| 718 | return; |
| 719 | |
Ming Lei | 49367d8 | 2008-12-12 21:38:45 +0800 | [diff] [blame] | 720 | atomic_dec(&urb->reject); |
Oliver Neukum | 55b447b | 2008-07-29 15:26:15 +0200 | [diff] [blame] | 721 | } |
| 722 | EXPORT_SYMBOL_GPL(usb_unpoison_urb); |
| 723 | |
| 724 | /** |
Oliver Neukum | 8815bb0 | 2012-04-30 09:13:46 +0200 | [diff] [blame] | 725 | * usb_block_urb - reliably prevent further use of an URB |
| 726 | * @urb: pointer to URB to be blocked, may be NULL |
| 727 | * |
| 728 | * After the routine has run, attempts to resubmit the URB will fail |
| 729 | * with error -EPERM. Thus even if the URB's completion handler always |
| 730 | * tries to resubmit, it will not succeed and the URB will become idle. |
| 731 | * |
| 732 | * The URB must not be deallocated while this routine is running. In |
| 733 | * particular, when a driver calls this routine, it must insure that the |
| 734 | * completion handler cannot deallocate the URB. |
| 735 | */ |
| 736 | void usb_block_urb(struct urb *urb) |
| 737 | { |
| 738 | if (!urb) |
| 739 | return; |
| 740 | |
| 741 | atomic_inc(&urb->reject); |
| 742 | } |
| 743 | EXPORT_SYMBOL_GPL(usb_block_urb); |
| 744 | |
| 745 | /** |
Oliver Neukum | 51a2f07 | 2007-05-25 13:40:56 +0200 | [diff] [blame] | 746 | * usb_kill_anchored_urbs - cancel transfer requests en masse |
| 747 | * @anchor: anchor the requests are bound to |
| 748 | * |
| 749 | * this allows all outstanding URBs to be killed starting |
| 750 | * from the back of the queue |
Alan Stern | cde217a | 2008-10-21 15:28:46 -0400 | [diff] [blame] | 751 | * |
| 752 | * This routine should not be called by a driver after its disconnect |
| 753 | * method has returned. |
Oliver Neukum | 51a2f07 | 2007-05-25 13:40:56 +0200 | [diff] [blame] | 754 | */ |
| 755 | void usb_kill_anchored_urbs(struct usb_anchor *anchor) |
| 756 | { |
| 757 | struct urb *victim; |
| 758 | |
| 759 | spin_lock_irq(&anchor->lock); |
| 760 | while (!list_empty(&anchor->urb_list)) { |
Greg Kroah-Hartman | 2c044a4 | 2008-01-30 15:21:33 -0800 | [diff] [blame] | 761 | victim = list_entry(anchor->urb_list.prev, struct urb, |
| 762 | anchor_list); |
Oliver Neukum | 51a2f07 | 2007-05-25 13:40:56 +0200 | [diff] [blame] | 763 | /* we must make sure the URB isn't freed before we kill it*/ |
| 764 | usb_get_urb(victim); |
| 765 | spin_unlock_irq(&anchor->lock); |
| 766 | /* this will unanchor the URB */ |
| 767 | usb_kill_urb(victim); |
| 768 | usb_put_urb(victim); |
| 769 | spin_lock_irq(&anchor->lock); |
| 770 | } |
| 771 | spin_unlock_irq(&anchor->lock); |
| 772 | } |
| 773 | EXPORT_SYMBOL_GPL(usb_kill_anchored_urbs); |
| 774 | |
Oliver Neukum | 6a2839b | 2008-07-29 16:18:47 +0200 | [diff] [blame] | 775 | |
| 776 | /** |
| 777 | * usb_poison_anchored_urbs - cease all traffic from an anchor |
| 778 | * @anchor: anchor the requests are bound to |
| 779 | * |
| 780 | * this allows all outstanding URBs to be poisoned starting |
| 781 | * from the back of the queue. Newly added URBs will also be |
| 782 | * poisoned |
Alan Stern | cde217a | 2008-10-21 15:28:46 -0400 | [diff] [blame] | 783 | * |
| 784 | * This routine should not be called by a driver after its disconnect |
| 785 | * method has returned. |
Oliver Neukum | 6a2839b | 2008-07-29 16:18:47 +0200 | [diff] [blame] | 786 | */ |
| 787 | void usb_poison_anchored_urbs(struct usb_anchor *anchor) |
| 788 | { |
| 789 | struct urb *victim; |
| 790 | |
| 791 | spin_lock_irq(&anchor->lock); |
| 792 | anchor->poisoned = 1; |
| 793 | while (!list_empty(&anchor->urb_list)) { |
| 794 | victim = list_entry(anchor->urb_list.prev, struct urb, |
| 795 | anchor_list); |
| 796 | /* we must make sure the URB isn't freed before we kill it*/ |
| 797 | usb_get_urb(victim); |
| 798 | spin_unlock_irq(&anchor->lock); |
| 799 | /* this will unanchor the URB */ |
| 800 | usb_poison_urb(victim); |
| 801 | usb_put_urb(victim); |
| 802 | spin_lock_irq(&anchor->lock); |
| 803 | } |
| 804 | spin_unlock_irq(&anchor->lock); |
| 805 | } |
| 806 | EXPORT_SYMBOL_GPL(usb_poison_anchored_urbs); |
Alan Stern | cde217a | 2008-10-21 15:28:46 -0400 | [diff] [blame] | 807 | |
Oliver Neukum | 51a2f07 | 2007-05-25 13:40:56 +0200 | [diff] [blame] | 808 | /** |
Oliver Neukum | 856395d | 2008-12-18 09:17:49 +0100 | [diff] [blame] | 809 | * usb_unpoison_anchored_urbs - let an anchor be used successfully again |
| 810 | * @anchor: anchor the requests are bound to |
| 811 | * |
| 812 | * Reverses the effect of usb_poison_anchored_urbs |
| 813 | * the anchor can be used normally after it returns |
| 814 | */ |
| 815 | void usb_unpoison_anchored_urbs(struct usb_anchor *anchor) |
| 816 | { |
| 817 | unsigned long flags; |
| 818 | struct urb *lazarus; |
| 819 | |
| 820 | spin_lock_irqsave(&anchor->lock, flags); |
| 821 | list_for_each_entry(lazarus, &anchor->urb_list, anchor_list) { |
| 822 | usb_unpoison_urb(lazarus); |
| 823 | } |
| 824 | anchor->poisoned = 0; |
| 825 | spin_unlock_irqrestore(&anchor->lock, flags); |
| 826 | } |
| 827 | EXPORT_SYMBOL_GPL(usb_unpoison_anchored_urbs); |
| 828 | /** |
Oliver Neukum | eda7695 | 2008-04-10 14:07:37 +0200 | [diff] [blame] | 829 | * usb_unlink_anchored_urbs - asynchronously cancel transfer requests en masse |
| 830 | * @anchor: anchor the requests are bound to |
| 831 | * |
| 832 | * this allows all outstanding URBs to be unlinked starting |
| 833 | * from the back of the queue. This function is asynchronous. |
Masanari Iida | e227867 | 2014-02-18 22:54:36 +0900 | [diff] [blame] | 834 | * The unlinking is just triggered. It may happen after this |
Oliver Neukum | eda7695 | 2008-04-10 14:07:37 +0200 | [diff] [blame] | 835 | * function has returned. |
Alan Stern | cde217a | 2008-10-21 15:28:46 -0400 | [diff] [blame] | 836 | * |
| 837 | * This routine should not be called by a driver after its disconnect |
| 838 | * method has returned. |
Oliver Neukum | eda7695 | 2008-04-10 14:07:37 +0200 | [diff] [blame] | 839 | */ |
| 840 | void usb_unlink_anchored_urbs(struct usb_anchor *anchor) |
| 841 | { |
| 842 | struct urb *victim; |
| 843 | |
Christian Lamparter | b3e6704 | 2010-08-03 02:32:28 +0200 | [diff] [blame] | 844 | while ((victim = usb_get_from_anchor(anchor)) != NULL) { |
Oliver Neukum | eda7695 | 2008-04-10 14:07:37 +0200 | [diff] [blame] | 845 | usb_unlink_urb(victim); |
Oliver Neukum | 77571f0 | 2008-08-18 16:36:52 +0200 | [diff] [blame] | 846 | usb_put_urb(victim); |
Oliver Neukum | eda7695 | 2008-04-10 14:07:37 +0200 | [diff] [blame] | 847 | } |
Oliver Neukum | eda7695 | 2008-04-10 14:07:37 +0200 | [diff] [blame] | 848 | } |
| 849 | EXPORT_SYMBOL_GPL(usb_unlink_anchored_urbs); |
| 850 | |
| 851 | /** |
Hans de Goede | 6ec4147 | 2013-10-09 17:01:41 +0200 | [diff] [blame] | 852 | * usb_anchor_suspend_wakeups |
| 853 | * @anchor: the anchor you want to suspend wakeups on |
| 854 | * |
| 855 | * Call this to stop the last urb being unanchored from waking up any |
| 856 | * usb_wait_anchor_empty_timeout waiters. This is used in the hcd urb give- |
| 857 | * back path to delay waking up until after the completion handler has run. |
| 858 | */ |
| 859 | void usb_anchor_suspend_wakeups(struct usb_anchor *anchor) |
| 860 | { |
| 861 | if (anchor) |
| 862 | atomic_inc(&anchor->suspend_wakeups); |
| 863 | } |
| 864 | EXPORT_SYMBOL_GPL(usb_anchor_suspend_wakeups); |
| 865 | |
| 866 | /** |
| 867 | * usb_anchor_resume_wakeups |
| 868 | * @anchor: the anchor you want to resume wakeups on |
| 869 | * |
| 870 | * Allow usb_wait_anchor_empty_timeout waiters to be woken up again, and |
| 871 | * wake up any current waiters if the anchor is empty. |
| 872 | */ |
| 873 | void usb_anchor_resume_wakeups(struct usb_anchor *anchor) |
| 874 | { |
| 875 | if (!anchor) |
| 876 | return; |
| 877 | |
| 878 | atomic_dec(&anchor->suspend_wakeups); |
| 879 | if (usb_anchor_check_wakeup(anchor)) |
| 880 | wake_up(&anchor->wait); |
| 881 | } |
| 882 | EXPORT_SYMBOL_GPL(usb_anchor_resume_wakeups); |
| 883 | |
| 884 | /** |
Oliver Neukum | 51a2f07 | 2007-05-25 13:40:56 +0200 | [diff] [blame] | 885 | * usb_wait_anchor_empty_timeout - wait for an anchor to be unused |
| 886 | * @anchor: the anchor you want to become unused |
| 887 | * @timeout: how long you are willing to wait in milliseconds |
| 888 | * |
| 889 | * Call this is you want to be sure all an anchor's |
| 890 | * URBs have finished |
Yacine Belkadi | 626f090 | 2013-08-02 20:10:04 +0200 | [diff] [blame] | 891 | * |
| 892 | * Return: Non-zero if the anchor became unused. Zero on timeout. |
Oliver Neukum | 51a2f07 | 2007-05-25 13:40:56 +0200 | [diff] [blame] | 893 | */ |
| 894 | int usb_wait_anchor_empty_timeout(struct usb_anchor *anchor, |
| 895 | unsigned int timeout) |
| 896 | { |
Hans de Goede | 6ec4147 | 2013-10-09 17:01:41 +0200 | [diff] [blame] | 897 | return wait_event_timeout(anchor->wait, |
| 898 | usb_anchor_check_wakeup(anchor), |
Oliver Neukum | 51a2f07 | 2007-05-25 13:40:56 +0200 | [diff] [blame] | 899 | msecs_to_jiffies(timeout)); |
| 900 | } |
| 901 | EXPORT_SYMBOL_GPL(usb_wait_anchor_empty_timeout); |
Oliver Neukum | 1987625 | 2008-08-25 22:40:25 +0200 | [diff] [blame] | 902 | |
| 903 | /** |
| 904 | * usb_get_from_anchor - get an anchor's oldest urb |
| 905 | * @anchor: the anchor whose urb you want |
| 906 | * |
Yacine Belkadi | 626f090 | 2013-08-02 20:10:04 +0200 | [diff] [blame] | 907 | * This will take the oldest urb from an anchor, |
Oliver Neukum | 1987625 | 2008-08-25 22:40:25 +0200 | [diff] [blame] | 908 | * unanchor and return it |
Yacine Belkadi | 626f090 | 2013-08-02 20:10:04 +0200 | [diff] [blame] | 909 | * |
| 910 | * Return: The oldest urb from @anchor, or %NULL if @anchor has no |
| 911 | * urbs associated with it. |
Oliver Neukum | 1987625 | 2008-08-25 22:40:25 +0200 | [diff] [blame] | 912 | */ |
| 913 | struct urb *usb_get_from_anchor(struct usb_anchor *anchor) |
| 914 | { |
| 915 | struct urb *victim; |
| 916 | unsigned long flags; |
| 917 | |
| 918 | spin_lock_irqsave(&anchor->lock, flags); |
| 919 | if (!list_empty(&anchor->urb_list)) { |
| 920 | victim = list_entry(anchor->urb_list.next, struct urb, |
| 921 | anchor_list); |
| 922 | usb_get_urb(victim); |
Christian Lamparter | b3e6704 | 2010-08-03 02:32:28 +0200 | [diff] [blame] | 923 | __usb_unanchor_urb(victim, anchor); |
Oliver Neukum | 1987625 | 2008-08-25 22:40:25 +0200 | [diff] [blame] | 924 | } else { |
Oliver Neukum | 1987625 | 2008-08-25 22:40:25 +0200 | [diff] [blame] | 925 | victim = NULL; |
| 926 | } |
Christian Lamparter | b3e6704 | 2010-08-03 02:32:28 +0200 | [diff] [blame] | 927 | spin_unlock_irqrestore(&anchor->lock, flags); |
Oliver Neukum | 1987625 | 2008-08-25 22:40:25 +0200 | [diff] [blame] | 928 | |
| 929 | return victim; |
| 930 | } |
| 931 | |
| 932 | EXPORT_SYMBOL_GPL(usb_get_from_anchor); |
| 933 | |
| 934 | /** |
| 935 | * usb_scuttle_anchored_urbs - unanchor all an anchor's urbs |
| 936 | * @anchor: the anchor whose urbs you want to unanchor |
| 937 | * |
| 938 | * use this to get rid of all an anchor's urbs |
| 939 | */ |
| 940 | void usb_scuttle_anchored_urbs(struct usb_anchor *anchor) |
| 941 | { |
| 942 | struct urb *victim; |
| 943 | unsigned long flags; |
| 944 | |
| 945 | spin_lock_irqsave(&anchor->lock, flags); |
| 946 | while (!list_empty(&anchor->urb_list)) { |
| 947 | victim = list_entry(anchor->urb_list.prev, struct urb, |
| 948 | anchor_list); |
Christian Lamparter | b3e6704 | 2010-08-03 02:32:28 +0200 | [diff] [blame] | 949 | __usb_unanchor_urb(victim, anchor); |
Oliver Neukum | 1987625 | 2008-08-25 22:40:25 +0200 | [diff] [blame] | 950 | } |
| 951 | spin_unlock_irqrestore(&anchor->lock, flags); |
| 952 | } |
| 953 | |
| 954 | EXPORT_SYMBOL_GPL(usb_scuttle_anchored_urbs); |
| 955 | |
| 956 | /** |
| 957 | * usb_anchor_empty - is an anchor empty |
| 958 | * @anchor: the anchor you want to query |
| 959 | * |
Yacine Belkadi | 626f090 | 2013-08-02 20:10:04 +0200 | [diff] [blame] | 960 | * Return: 1 if the anchor has no urbs associated with it. |
Oliver Neukum | 1987625 | 2008-08-25 22:40:25 +0200 | [diff] [blame] | 961 | */ |
| 962 | int usb_anchor_empty(struct usb_anchor *anchor) |
| 963 | { |
| 964 | return list_empty(&anchor->urb_list); |
| 965 | } |
| 966 | |
| 967 | EXPORT_SYMBOL_GPL(usb_anchor_empty); |
| 968 | |