1 /* 2 * USB hub driver. 3 * 4 * (C) Copyright 1999 Linus Torvalds 5 * (C) Copyright 1999 Johannes Erdfelt 6 * (C) Copyright 1999 Gregory P. Smith 7 * (C) Copyright 2001 Brad Hards (bhards@bigpond.net.au) 8 * 9 */ 10 11 #include <linux/kernel.h> 12 #include <linux/errno.h> 13 #include <linux/module.h> 14 #include <linux/moduleparam.h> 15 #include <linux/completion.h> 16 #include <linux/sched.h> 17 #include <linux/list.h> 18 #include <linux/slab.h> 19 #include <linux/ioctl.h> 20 #include <linux/usb.h> 21 #include <linux/usbdevice_fs.h> 22 #include <linux/usb/hcd.h> 23 #include <linux/usb/quirks.h> 24 #include <linux/kthread.h> 25 #include <linux/mutex.h> 26 #include <linux/freezer.h> 27 #include <linux/pm_runtime.h> 28 29 #include <asm/uaccess.h> 30 #include <asm/byteorder.h> 31 32 #include "usb.h" 33 34 /* if we are in debug mode, always announce new devices */ 35 #ifdef DEBUG 36 #ifndef CONFIG_USB_ANNOUNCE_NEW_DEVICES 37 #define CONFIG_USB_ANNOUNCE_NEW_DEVICES 38 #endif 39 #endif 40 41 struct usb_hub { 42 struct device *intfdev; /* the "interface" device */ 43 struct usb_device *hdev; 44 struct kref kref; 45 struct urb *urb; /* for interrupt polling pipe */ 46 47 /* buffer for urb ... with extra space in case of babble */ 48 char (*buffer)[8]; 49 union { 50 struct usb_hub_status hub; 51 struct usb_port_status port; 52 } *status; /* buffer for status reports */ 53 struct mutex status_mutex; /* for the status buffer */ 54 55 int error; /* last reported error */ 56 int nerrors; /* track consecutive errors */ 57 58 struct list_head event_list; /* hubs w/data or errs ready */ 59 unsigned long event_bits[1]; /* status change bitmask */ 60 unsigned long change_bits[1]; /* ports with logical connect 61 status change */ 62 unsigned long busy_bits[1]; /* ports being reset or 63 resumed */ 64 unsigned long removed_bits[1]; /* ports with a "removed" 65 device present */ 66 #if USB_MAXCHILDREN > 31 /* 8*sizeof(unsigned long) - 1 */ 67 #error event_bits[] is too short! 68 #endif 69 70 struct usb_hub_descriptor *descriptor; /* class descriptor */ 71 struct usb_tt tt; /* Transaction Translator */ 72 73 unsigned mA_per_port; /* current for each child */ 74 75 unsigned limited_power:1; 76 unsigned quiescing:1; 77 unsigned disconnected:1; 78 79 unsigned has_indicators:1; 80 u8 indicator[USB_MAXCHILDREN]; 81 struct delayed_work leds; 82 struct delayed_work init_work; 83 void **port_owners; 84 }; 85 86 87 /* Protect struct usb_device->state and ->children members 88 * Note: Both are also protected by ->dev.sem, except that ->state can 89 * change to USB_STATE_NOTATTACHED even when the semaphore isn't held. */ 90 static DEFINE_SPINLOCK(device_state_lock); 91 92 /* khubd's worklist and its lock */ 93 static DEFINE_SPINLOCK(hub_event_lock); 94 static LIST_HEAD(hub_event_list); /* List of hubs needing servicing */ 95 96 /* Wakes up khubd */ 97 static DECLARE_WAIT_QUEUE_HEAD(khubd_wait); 98 99 static struct task_struct *khubd_task; 100 101 /* cycle leds on hubs that aren't blinking for attention */ 102 static int blinkenlights = 0; 103 module_param (blinkenlights, bool, S_IRUGO); 104 MODULE_PARM_DESC (blinkenlights, "true to cycle leds on hubs"); 105 106 /* 107 * Device SATA8000 FW1.0 from DATAST0R Technology Corp requires about 108 * 10 seconds to send reply for the initial 64-byte descriptor request. 109 */ 110 /* define initial 64-byte descriptor request timeout in milliseconds */ 111 static int initial_descriptor_timeout = USB_CTRL_GET_TIMEOUT; 112 module_param(initial_descriptor_timeout, int, S_IRUGO|S_IWUSR); 113 MODULE_PARM_DESC(initial_descriptor_timeout, 114 "initial 64-byte descriptor request timeout in milliseconds " 115 "(default 5000 - 5.0 seconds)"); 116 117 /* 118 * As of 2.6.10 we introduce a new USB device initialization scheme which 119 * closely resembles the way Windows works. Hopefully it will be compatible 120 * with a wider range of devices than the old scheme. However some previously 121 * working devices may start giving rise to "device not accepting address" 122 * errors; if that happens the user can try the old scheme by adjusting the 123 * following module parameters. 124 * 125 * For maximum flexibility there are two boolean parameters to control the 126 * hub driver's behavior. On the first initialization attempt, if the 127 * "old_scheme_first" parameter is set then the old scheme will be used, 128 * otherwise the new scheme is used. If that fails and "use_both_schemes" 129 * is set, then the driver will make another attempt, using the other scheme. 130 */ 131 static int old_scheme_first = 0; 132 module_param(old_scheme_first, bool, S_IRUGO | S_IWUSR); 133 MODULE_PARM_DESC(old_scheme_first, 134 "start with the old device initialization scheme"); 135 136 static int use_both_schemes = 1; 137 module_param(use_both_schemes, bool, S_IRUGO | S_IWUSR); 138 MODULE_PARM_DESC(use_both_schemes, 139 "try the other device initialization scheme if the " 140 "first one fails"); 141 142 /* Mutual exclusion for EHCI CF initialization. This interferes with 143 * port reset on some companion controllers. 144 */ 145 DECLARE_RWSEM(ehci_cf_port_reset_rwsem); 146 EXPORT_SYMBOL_GPL(ehci_cf_port_reset_rwsem); 147 148 #define HUB_DEBOUNCE_TIMEOUT 1500 149 #define HUB_DEBOUNCE_STEP 25 150 #define HUB_DEBOUNCE_STABLE 100 151 152 153 static int usb_reset_and_verify_device(struct usb_device *udev); 154 155 static inline char *portspeed(int portstatus) 156 { 157 if (portstatus & USB_PORT_STAT_HIGH_SPEED) 158 return "480 Mb/s"; 159 else if (portstatus & USB_PORT_STAT_LOW_SPEED) 160 return "1.5 Mb/s"; 161 else if (portstatus & USB_PORT_STAT_SUPER_SPEED) 162 return "5.0 Gb/s"; 163 else 164 return "12 Mb/s"; 165 } 166 167 /* Note that hdev or one of its children must be locked! */ 168 static struct usb_hub *hdev_to_hub(struct usb_device *hdev) 169 { 170 if (!hdev || !hdev->actconfig) 171 return NULL; 172 return usb_get_intfdata(hdev->actconfig->interface[0]); 173 } 174 175 /* USB 2.0 spec Section 11.24.4.5 */ 176 static int get_hub_descriptor(struct usb_device *hdev, void *data, int size) 177 { 178 int i, ret; 179 180 for (i = 0; i < 3; i++) { 181 ret = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0), 182 USB_REQ_GET_DESCRIPTOR, USB_DIR_IN | USB_RT_HUB, 183 USB_DT_HUB << 8, 0, data, size, 184 USB_CTRL_GET_TIMEOUT); 185 if (ret >= (USB_DT_HUB_NONVAR_SIZE + 2)) 186 return ret; 187 } 188 return -EINVAL; 189 } 190 191 /* 192 * USB 2.0 spec Section 11.24.2.1 193 */ 194 static int clear_hub_feature(struct usb_device *hdev, int feature) 195 { 196 return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0), 197 USB_REQ_CLEAR_FEATURE, USB_RT_HUB, feature, 0, NULL, 0, 1000); 198 } 199 200 /* 201 * USB 2.0 spec Section 11.24.2.2 202 */ 203 static int clear_port_feature(struct usb_device *hdev, int port1, int feature) 204 { 205 return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0), 206 USB_REQ_CLEAR_FEATURE, USB_RT_PORT, feature, port1, 207 NULL, 0, 1000); 208 } 209 210 /* 211 * USB 2.0 spec Section 11.24.2.13 212 */ 213 static int set_port_feature(struct usb_device *hdev, int port1, int feature) 214 { 215 return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0), 216 USB_REQ_SET_FEATURE, USB_RT_PORT, feature, port1, 217 NULL, 0, 1000); 218 } 219 220 /* 221 * USB 2.0 spec Section 11.24.2.7.1.10 and table 11-7 222 * for info about using port indicators 223 */ 224 static void set_port_led( 225 struct usb_hub *hub, 226 int port1, 227 int selector 228 ) 229 { 230 int status = set_port_feature(hub->hdev, (selector << 8) | port1, 231 USB_PORT_FEAT_INDICATOR); 232 if (status < 0) 233 dev_dbg (hub->intfdev, 234 "port %d indicator %s status %d\n", 235 port1, 236 ({ char *s; switch (selector) { 237 case HUB_LED_AMBER: s = "amber"; break; 238 case HUB_LED_GREEN: s = "green"; break; 239 case HUB_LED_OFF: s = "off"; break; 240 case HUB_LED_AUTO: s = "auto"; break; 241 default: s = "??"; break; 242 }; s; }), 243 status); 244 } 245 246 #define LED_CYCLE_PERIOD ((2*HZ)/3) 247 248 static void led_work (struct work_struct *work) 249 { 250 struct usb_hub *hub = 251 container_of(work, struct usb_hub, leds.work); 252 struct usb_device *hdev = hub->hdev; 253 unsigned i; 254 unsigned changed = 0; 255 int cursor = -1; 256 257 if (hdev->state != USB_STATE_CONFIGURED || hub->quiescing) 258 return; 259 260 for (i = 0; i < hub->descriptor->bNbrPorts; i++) { 261 unsigned selector, mode; 262 263 /* 30%-50% duty cycle */ 264 265 switch (hub->indicator[i]) { 266 /* cycle marker */ 267 case INDICATOR_CYCLE: 268 cursor = i; 269 selector = HUB_LED_AUTO; 270 mode = INDICATOR_AUTO; 271 break; 272 /* blinking green = sw attention */ 273 case INDICATOR_GREEN_BLINK: 274 selector = HUB_LED_GREEN; 275 mode = INDICATOR_GREEN_BLINK_OFF; 276 break; 277 case INDICATOR_GREEN_BLINK_OFF: 278 selector = HUB_LED_OFF; 279 mode = INDICATOR_GREEN_BLINK; 280 break; 281 /* blinking amber = hw attention */ 282 case INDICATOR_AMBER_BLINK: 283 selector = HUB_LED_AMBER; 284 mode = INDICATOR_AMBER_BLINK_OFF; 285 break; 286 case INDICATOR_AMBER_BLINK_OFF: 287 selector = HUB_LED_OFF; 288 mode = INDICATOR_AMBER_BLINK; 289 break; 290 /* blink green/amber = reserved */ 291 case INDICATOR_ALT_BLINK: 292 selector = HUB_LED_GREEN; 293 mode = INDICATOR_ALT_BLINK_OFF; 294 break; 295 case INDICATOR_ALT_BLINK_OFF: 296 selector = HUB_LED_AMBER; 297 mode = INDICATOR_ALT_BLINK; 298 break; 299 default: 300 continue; 301 } 302 if (selector != HUB_LED_AUTO) 303 changed = 1; 304 set_port_led(hub, i + 1, selector); 305 hub->indicator[i] = mode; 306 } 307 if (!changed && blinkenlights) { 308 cursor++; 309 cursor %= hub->descriptor->bNbrPorts; 310 set_port_led(hub, cursor + 1, HUB_LED_GREEN); 311 hub->indicator[cursor] = INDICATOR_CYCLE; 312 changed++; 313 } 314 if (changed) 315 schedule_delayed_work(&hub->leds, LED_CYCLE_PERIOD); 316 } 317 318 /* use a short timeout for hub/port status fetches */ 319 #define USB_STS_TIMEOUT 1000 320 #define USB_STS_RETRIES 5 321 322 /* 323 * USB 2.0 spec Section 11.24.2.6 324 */ 325 static int get_hub_status(struct usb_device *hdev, 326 struct usb_hub_status *data) 327 { 328 int i, status = -ETIMEDOUT; 329 330 for (i = 0; i < USB_STS_RETRIES && status == -ETIMEDOUT; i++) { 331 status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0), 332 USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_HUB, 0, 0, 333 data, sizeof(*data), USB_STS_TIMEOUT); 334 } 335 return status; 336 } 337 338 /* 339 * USB 2.0 spec Section 11.24.2.7 340 */ 341 static int get_port_status(struct usb_device *hdev, int port1, 342 struct usb_port_status *data) 343 { 344 int i, status = -ETIMEDOUT; 345 346 for (i = 0; i < USB_STS_RETRIES && status == -ETIMEDOUT; i++) { 347 status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0), 348 USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_PORT, 0, port1, 349 data, sizeof(*data), USB_STS_TIMEOUT); 350 } 351 return status; 352 } 353 354 static int hub_port_status(struct usb_hub *hub, int port1, 355 u16 *status, u16 *change) 356 { 357 int ret; 358 359 mutex_lock(&hub->status_mutex); 360 ret = get_port_status(hub->hdev, port1, &hub->status->port); 361 if (ret < 4) { 362 dev_err(hub->intfdev, 363 "%s failed (err = %d)\n", __func__, ret); 364 if (ret >= 0) 365 ret = -EIO; 366 } else { 367 *status = le16_to_cpu(hub->status->port.wPortStatus); 368 *change = le16_to_cpu(hub->status->port.wPortChange); 369 ret = 0; 370 } 371 mutex_unlock(&hub->status_mutex); 372 return ret; 373 } 374 375 static void kick_khubd(struct usb_hub *hub) 376 { 377 unsigned long flags; 378 379 spin_lock_irqsave(&hub_event_lock, flags); 380 if (!hub->disconnected && list_empty(&hub->event_list)) { 381 list_add_tail(&hub->event_list, &hub_event_list); 382 383 /* Suppress autosuspend until khubd runs */ 384 usb_autopm_get_interface_no_resume( 385 to_usb_interface(hub->intfdev)); 386 wake_up(&khubd_wait); 387 } 388 spin_unlock_irqrestore(&hub_event_lock, flags); 389 } 390 391 void usb_kick_khubd(struct usb_device *hdev) 392 { 393 struct usb_hub *hub = hdev_to_hub(hdev); 394 395 if (hub) 396 kick_khubd(hub); 397 } 398 399 400 /* completion function, fires on port status changes and various faults */ 401 static void hub_irq(struct urb *urb) 402 { 403 struct usb_hub *hub = urb->context; 404 int status = urb->status; 405 unsigned i; 406 unsigned long bits; 407 408 switch (status) { 409 case -ENOENT: /* synchronous unlink */ 410 case -ECONNRESET: /* async unlink */ 411 case -ESHUTDOWN: /* hardware going away */ 412 return; 413 414 default: /* presumably an error */ 415 /* Cause a hub reset after 10 consecutive errors */ 416 dev_dbg (hub->intfdev, "transfer --> %d\n", status); 417 if ((++hub->nerrors < 10) || hub->error) 418 goto resubmit; 419 hub->error = status; 420 /* FALL THROUGH */ 421 422 /* let khubd handle things */ 423 case 0: /* we got data: port status changed */ 424 bits = 0; 425 for (i = 0; i < urb->actual_length; ++i) 426 bits |= ((unsigned long) ((*hub->buffer)[i])) 427 << (i*8); 428 hub->event_bits[0] = bits; 429 break; 430 } 431 432 hub->nerrors = 0; 433 434 /* Something happened, let khubd figure it out */ 435 kick_khubd(hub); 436 437 resubmit: 438 if (hub->quiescing) 439 return; 440 441 if ((status = usb_submit_urb (hub->urb, GFP_ATOMIC)) != 0 442 && status != -ENODEV && status != -EPERM) 443 dev_err (hub->intfdev, "resubmit --> %d\n", status); 444 } 445 446 /* USB 2.0 spec Section 11.24.2.3 */ 447 static inline int 448 hub_clear_tt_buffer (struct usb_device *hdev, u16 devinfo, u16 tt) 449 { 450 return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0), 451 HUB_CLEAR_TT_BUFFER, USB_RT_PORT, devinfo, 452 tt, NULL, 0, 1000); 453 } 454 455 /* 456 * enumeration blocks khubd for a long time. we use keventd instead, since 457 * long blocking there is the exception, not the rule. accordingly, HCDs 458 * talking to TTs must queue control transfers (not just bulk and iso), so 459 * both can talk to the same hub concurrently. 460 */ 461 static void hub_tt_work(struct work_struct *work) 462 { 463 struct usb_hub *hub = 464 container_of(work, struct usb_hub, tt.clear_work); 465 unsigned long flags; 466 int limit = 100; 467 468 spin_lock_irqsave (&hub->tt.lock, flags); 469 while (--limit && !list_empty (&hub->tt.clear_list)) { 470 struct list_head *next; 471 struct usb_tt_clear *clear; 472 struct usb_device *hdev = hub->hdev; 473 const struct hc_driver *drv; 474 int status; 475 476 next = hub->tt.clear_list.next; 477 clear = list_entry (next, struct usb_tt_clear, clear_list); 478 list_del (&clear->clear_list); 479 480 /* drop lock so HCD can concurrently report other TT errors */ 481 spin_unlock_irqrestore (&hub->tt.lock, flags); 482 status = hub_clear_tt_buffer (hdev, clear->devinfo, clear->tt); 483 if (status) 484 dev_err (&hdev->dev, 485 "clear tt %d (%04x) error %d\n", 486 clear->tt, clear->devinfo, status); 487 488 /* Tell the HCD, even if the operation failed */ 489 drv = clear->hcd->driver; 490 if (drv->clear_tt_buffer_complete) 491 (drv->clear_tt_buffer_complete)(clear->hcd, clear->ep); 492 493 kfree(clear); 494 spin_lock_irqsave(&hub->tt.lock, flags); 495 } 496 spin_unlock_irqrestore (&hub->tt.lock, flags); 497 } 498 499 /** 500 * usb_hub_clear_tt_buffer - clear control/bulk TT state in high speed hub 501 * @urb: an URB associated with the failed or incomplete split transaction 502 * 503 * High speed HCDs use this to tell the hub driver that some split control or 504 * bulk transaction failed in a way that requires clearing internal state of 505 * a transaction translator. This is normally detected (and reported) from 506 * interrupt context. 507 * 508 * It may not be possible for that hub to handle additional full (or low) 509 * speed transactions until that state is fully cleared out. 510 */ 511 int usb_hub_clear_tt_buffer(struct urb *urb) 512 { 513 struct usb_device *udev = urb->dev; 514 int pipe = urb->pipe; 515 struct usb_tt *tt = udev->tt; 516 unsigned long flags; 517 struct usb_tt_clear *clear; 518 519 /* we've got to cope with an arbitrary number of pending TT clears, 520 * since each TT has "at least two" buffers that can need it (and 521 * there can be many TTs per hub). even if they're uncommon. 522 */ 523 if ((clear = kmalloc (sizeof *clear, GFP_ATOMIC)) == NULL) { 524 dev_err (&udev->dev, "can't save CLEAR_TT_BUFFER state\n"); 525 /* FIXME recover somehow ... RESET_TT? */ 526 return -ENOMEM; 527 } 528 529 /* info that CLEAR_TT_BUFFER needs */ 530 clear->tt = tt->multi ? udev->ttport : 1; 531 clear->devinfo = usb_pipeendpoint (pipe); 532 clear->devinfo |= udev->devnum << 4; 533 clear->devinfo |= usb_pipecontrol (pipe) 534 ? (USB_ENDPOINT_XFER_CONTROL << 11) 535 : (USB_ENDPOINT_XFER_BULK << 11); 536 if (usb_pipein (pipe)) 537 clear->devinfo |= 1 << 15; 538 539 /* info for completion callback */ 540 clear->hcd = bus_to_hcd(udev->bus); 541 clear->ep = urb->ep; 542 543 /* tell keventd to clear state for this TT */ 544 spin_lock_irqsave (&tt->lock, flags); 545 list_add_tail (&clear->clear_list, &tt->clear_list); 546 schedule_work(&tt->clear_work); 547 spin_unlock_irqrestore (&tt->lock, flags); 548 return 0; 549 } 550 EXPORT_SYMBOL_GPL(usb_hub_clear_tt_buffer); 551 552 /* If do_delay is false, return the number of milliseconds the caller 553 * needs to delay. 554 */ 555 static unsigned hub_power_on(struct usb_hub *hub, bool do_delay) 556 { 557 int port1; 558 unsigned pgood_delay = hub->descriptor->bPwrOn2PwrGood * 2; 559 unsigned delay; 560 u16 wHubCharacteristics = 561 le16_to_cpu(hub->descriptor->wHubCharacteristics); 562 563 /* Enable power on each port. Some hubs have reserved values 564 * of LPSM (> 2) in their descriptors, even though they are 565 * USB 2.0 hubs. Some hubs do not implement port-power switching 566 * but only emulate it. In all cases, the ports won't work 567 * unless we send these messages to the hub. 568 */ 569 if ((wHubCharacteristics & HUB_CHAR_LPSM) < 2) 570 dev_dbg(hub->intfdev, "enabling power on all ports\n"); 571 else 572 dev_dbg(hub->intfdev, "trying to enable port power on " 573 "non-switchable hub\n"); 574 for (port1 = 1; port1 <= hub->descriptor->bNbrPorts; port1++) 575 set_port_feature(hub->hdev, port1, USB_PORT_FEAT_POWER); 576 577 /* Wait at least 100 msec for power to become stable */ 578 delay = max(pgood_delay, (unsigned) 100); 579 if (do_delay) 580 msleep(delay); 581 return delay; 582 } 583 584 static int hub_hub_status(struct usb_hub *hub, 585 u16 *status, u16 *change) 586 { 587 int ret; 588 589 mutex_lock(&hub->status_mutex); 590 ret = get_hub_status(hub->hdev, &hub->status->hub); 591 if (ret < 0) 592 dev_err (hub->intfdev, 593 "%s failed (err = %d)\n", __func__, ret); 594 else { 595 *status = le16_to_cpu(hub->status->hub.wHubStatus); 596 *change = le16_to_cpu(hub->status->hub.wHubChange); 597 ret = 0; 598 } 599 mutex_unlock(&hub->status_mutex); 600 return ret; 601 } 602 603 static int hub_port_disable(struct usb_hub *hub, int port1, int set_state) 604 { 605 struct usb_device *hdev = hub->hdev; 606 int ret = 0; 607 608 if (hdev->children[port1-1] && set_state) 609 usb_set_device_state(hdev->children[port1-1], 610 USB_STATE_NOTATTACHED); 611 if (!hub->error) 612 ret = clear_port_feature(hdev, port1, USB_PORT_FEAT_ENABLE); 613 if (ret) 614 dev_err(hub->intfdev, "cannot disable port %d (err = %d)\n", 615 port1, ret); 616 return ret; 617 } 618 619 /* 620 * Disable a port and mark a logical connnect-change event, so that some 621 * time later khubd will disconnect() any existing usb_device on the port 622 * and will re-enumerate if there actually is a device attached. 623 */ 624 static void hub_port_logical_disconnect(struct usb_hub *hub, int port1) 625 { 626 dev_dbg(hub->intfdev, "logical disconnect on port %d\n", port1); 627 hub_port_disable(hub, port1, 1); 628 629 /* FIXME let caller ask to power down the port: 630 * - some devices won't enumerate without a VBUS power cycle 631 * - SRP saves power that way 632 * - ... new call, TBD ... 633 * That's easy if this hub can switch power per-port, and 634 * khubd reactivates the port later (timer, SRP, etc). 635 * Powerdown must be optional, because of reset/DFU. 636 */ 637 638 set_bit(port1, hub->change_bits); 639 kick_khubd(hub); 640 } 641 642 /** 643 * usb_remove_device - disable a device's port on its parent hub 644 * @udev: device to be disabled and removed 645 * Context: @udev locked, must be able to sleep. 646 * 647 * After @udev's port has been disabled, khubd is notified and it will 648 * see that the device has been disconnected. When the device is 649 * physically unplugged and something is plugged in, the events will 650 * be received and processed normally. 651 */ 652 int usb_remove_device(struct usb_device *udev) 653 { 654 struct usb_hub *hub; 655 struct usb_interface *intf; 656 657 if (!udev->parent) /* Can't remove a root hub */ 658 return -EINVAL; 659 hub = hdev_to_hub(udev->parent); 660 intf = to_usb_interface(hub->intfdev); 661 662 usb_autopm_get_interface(intf); 663 set_bit(udev->portnum, hub->removed_bits); 664 hub_port_logical_disconnect(hub, udev->portnum); 665 usb_autopm_put_interface(intf); 666 return 0; 667 } 668 669 enum hub_activation_type { 670 HUB_INIT, HUB_INIT2, HUB_INIT3, /* INITs must come first */ 671 HUB_POST_RESET, HUB_RESUME, HUB_RESET_RESUME, 672 }; 673 674 static void hub_init_func2(struct work_struct *ws); 675 static void hub_init_func3(struct work_struct *ws); 676 677 static void hub_activate(struct usb_hub *hub, enum hub_activation_type type) 678 { 679 struct usb_device *hdev = hub->hdev; 680 int port1; 681 int status; 682 bool need_debounce_delay = false; 683 unsigned delay; 684 685 /* Continue a partial initialization */ 686 if (type == HUB_INIT2) 687 goto init2; 688 if (type == HUB_INIT3) 689 goto init3; 690 691 /* After a resume, port power should still be on. 692 * For any other type of activation, turn it on. 693 */ 694 if (type != HUB_RESUME) { 695 696 /* Speed up system boot by using a delayed_work for the 697 * hub's initial power-up delays. This is pretty awkward 698 * and the implementation looks like a home-brewed sort of 699 * setjmp/longjmp, but it saves at least 100 ms for each 700 * root hub (assuming usbcore is compiled into the kernel 701 * rather than as a module). It adds up. 702 * 703 * This can't be done for HUB_RESUME or HUB_RESET_RESUME 704 * because for those activation types the ports have to be 705 * operational when we return. In theory this could be done 706 * for HUB_POST_RESET, but it's easier not to. 707 */ 708 if (type == HUB_INIT) { 709 delay = hub_power_on(hub, false); 710 PREPARE_DELAYED_WORK(&hub->init_work, hub_init_func2); 711 schedule_delayed_work(&hub->init_work, 712 msecs_to_jiffies(delay)); 713 714 /* Suppress autosuspend until init is done */ 715 usb_autopm_get_interface_no_resume( 716 to_usb_interface(hub->intfdev)); 717 return; /* Continues at init2: below */ 718 } else { 719 hub_power_on(hub, true); 720 } 721 } 722 init2: 723 724 /* Check each port and set hub->change_bits to let khubd know 725 * which ports need attention. 726 */ 727 for (port1 = 1; port1 <= hdev->maxchild; ++port1) { 728 struct usb_device *udev = hdev->children[port1-1]; 729 u16 portstatus, portchange; 730 731 portstatus = portchange = 0; 732 status = hub_port_status(hub, port1, &portstatus, &portchange); 733 if (udev || (portstatus & USB_PORT_STAT_CONNECTION)) 734 dev_dbg(hub->intfdev, 735 "port %d: status %04x change %04x\n", 736 port1, portstatus, portchange); 737 738 /* After anything other than HUB_RESUME (i.e., initialization 739 * or any sort of reset), every port should be disabled. 740 * Unconnected ports should likewise be disabled (paranoia), 741 * and so should ports for which we have no usb_device. 742 */ 743 if ((portstatus & USB_PORT_STAT_ENABLE) && ( 744 type != HUB_RESUME || 745 !(portstatus & USB_PORT_STAT_CONNECTION) || 746 !udev || 747 udev->state == USB_STATE_NOTATTACHED)) { 748 /* 749 * USB3 protocol ports will automatically transition 750 * to Enabled state when detect an USB3.0 device attach. 751 * Do not disable USB3 protocol ports. 752 * FIXME: USB3 root hub and external hubs are treated 753 * differently here. 754 */ 755 if (hdev->descriptor.bDeviceProtocol != 3 || 756 (!hdev->parent && 757 !(portstatus & USB_PORT_STAT_SUPER_SPEED))) { 758 clear_port_feature(hdev, port1, 759 USB_PORT_FEAT_ENABLE); 760 portstatus &= ~USB_PORT_STAT_ENABLE; 761 } 762 } 763 764 /* Clear status-change flags; we'll debounce later */ 765 if (portchange & USB_PORT_STAT_C_CONNECTION) { 766 need_debounce_delay = true; 767 clear_port_feature(hub->hdev, port1, 768 USB_PORT_FEAT_C_CONNECTION); 769 } 770 if (portchange & USB_PORT_STAT_C_ENABLE) { 771 need_debounce_delay = true; 772 clear_port_feature(hub->hdev, port1, 773 USB_PORT_FEAT_C_ENABLE); 774 } 775 776 /* We can forget about a "removed" device when there's a 777 * physical disconnect or the connect status changes. 778 */ 779 if (!(portstatus & USB_PORT_STAT_CONNECTION) || 780 (portchange & USB_PORT_STAT_C_CONNECTION)) 781 clear_bit(port1, hub->removed_bits); 782 783 if (!udev || udev->state == USB_STATE_NOTATTACHED) { 784 /* Tell khubd to disconnect the device or 785 * check for a new connection 786 */ 787 if (udev || (portstatus & USB_PORT_STAT_CONNECTION)) 788 set_bit(port1, hub->change_bits); 789 790 } else if (portstatus & USB_PORT_STAT_ENABLE) { 791 /* The power session apparently survived the resume. 792 * If there was an overcurrent or suspend change 793 * (i.e., remote wakeup request), have khubd 794 * take care of it. 795 */ 796 if (portchange) 797 set_bit(port1, hub->change_bits); 798 799 } else if (udev->persist_enabled) { 800 #ifdef CONFIG_PM 801 udev->reset_resume = 1; 802 #endif 803 set_bit(port1, hub->change_bits); 804 805 } else { 806 /* The power session is gone; tell khubd */ 807 usb_set_device_state(udev, USB_STATE_NOTATTACHED); 808 set_bit(port1, hub->change_bits); 809 } 810 } 811 812 /* If no port-status-change flags were set, we don't need any 813 * debouncing. If flags were set we can try to debounce the 814 * ports all at once right now, instead of letting khubd do them 815 * one at a time later on. 816 * 817 * If any port-status changes do occur during this delay, khubd 818 * will see them later and handle them normally. 819 */ 820 if (need_debounce_delay) { 821 delay = HUB_DEBOUNCE_STABLE; 822 823 /* Don't do a long sleep inside a workqueue routine */ 824 if (type == HUB_INIT2) { 825 PREPARE_DELAYED_WORK(&hub->init_work, hub_init_func3); 826 schedule_delayed_work(&hub->init_work, 827 msecs_to_jiffies(delay)); 828 return; /* Continues at init3: below */ 829 } else { 830 msleep(delay); 831 } 832 } 833 init3: 834 hub->quiescing = 0; 835 836 status = usb_submit_urb(hub->urb, GFP_NOIO); 837 if (status < 0) 838 dev_err(hub->intfdev, "activate --> %d\n", status); 839 if (hub->has_indicators && blinkenlights) 840 schedule_delayed_work(&hub->leds, LED_CYCLE_PERIOD); 841 842 /* Scan all ports that need attention */ 843 kick_khubd(hub); 844 845 /* Allow autosuspend if it was suppressed */ 846 if (type <= HUB_INIT3) 847 usb_autopm_put_interface_async(to_usb_interface(hub->intfdev)); 848 } 849 850 /* Implement the continuations for the delays above */ 851 static void hub_init_func2(struct work_struct *ws) 852 { 853 struct usb_hub *hub = container_of(ws, struct usb_hub, init_work.work); 854 855 hub_activate(hub, HUB_INIT2); 856 } 857 858 static void hub_init_func3(struct work_struct *ws) 859 { 860 struct usb_hub *hub = container_of(ws, struct usb_hub, init_work.work); 861 862 hub_activate(hub, HUB_INIT3); 863 } 864 865 enum hub_quiescing_type { 866 HUB_DISCONNECT, HUB_PRE_RESET, HUB_SUSPEND 867 }; 868 869 static void hub_quiesce(struct usb_hub *hub, enum hub_quiescing_type type) 870 { 871 struct usb_device *hdev = hub->hdev; 872 int i; 873 874 cancel_delayed_work_sync(&hub->init_work); 875 876 /* khubd and related activity won't re-trigger */ 877 hub->quiescing = 1; 878 879 if (type != HUB_SUSPEND) { 880 /* Disconnect all the children */ 881 for (i = 0; i < hdev->maxchild; ++i) { 882 if (hdev->children[i]) 883 usb_disconnect(&hdev->children[i]); 884 } 885 } 886 887 /* Stop khubd and related activity */ 888 usb_kill_urb(hub->urb); 889 if (hub->has_indicators) 890 cancel_delayed_work_sync(&hub->leds); 891 if (hub->tt.hub) 892 cancel_work_sync(&hub->tt.clear_work); 893 } 894 895 /* caller has locked the hub device */ 896 static int hub_pre_reset(struct usb_interface *intf) 897 { 898 struct usb_hub *hub = usb_get_intfdata(intf); 899 900 hub_quiesce(hub, HUB_PRE_RESET); 901 return 0; 902 } 903 904 /* caller has locked the hub device */ 905 static int hub_post_reset(struct usb_interface *intf) 906 { 907 struct usb_hub *hub = usb_get_intfdata(intf); 908 909 hub_activate(hub, HUB_POST_RESET); 910 return 0; 911 } 912 913 static int hub_configure(struct usb_hub *hub, 914 struct usb_endpoint_descriptor *endpoint) 915 { 916 struct usb_hcd *hcd; 917 struct usb_device *hdev = hub->hdev; 918 struct device *hub_dev = hub->intfdev; 919 u16 hubstatus, hubchange; 920 u16 wHubCharacteristics; 921 unsigned int pipe; 922 int maxp, ret; 923 char *message = "out of memory"; 924 925 hub->buffer = kmalloc(sizeof(*hub->buffer), GFP_KERNEL); 926 if (!hub->buffer) { 927 ret = -ENOMEM; 928 goto fail; 929 } 930 931 hub->status = kmalloc(sizeof(*hub->status), GFP_KERNEL); 932 if (!hub->status) { 933 ret = -ENOMEM; 934 goto fail; 935 } 936 mutex_init(&hub->status_mutex); 937 938 hub->descriptor = kmalloc(sizeof(*hub->descriptor), GFP_KERNEL); 939 if (!hub->descriptor) { 940 ret = -ENOMEM; 941 goto fail; 942 } 943 944 /* Request the entire hub descriptor. 945 * hub->descriptor can handle USB_MAXCHILDREN ports, 946 * but the hub can/will return fewer bytes here. 947 */ 948 ret = get_hub_descriptor(hdev, hub->descriptor, 949 sizeof(*hub->descriptor)); 950 if (ret < 0) { 951 message = "can't read hub descriptor"; 952 goto fail; 953 } else if (hub->descriptor->bNbrPorts > USB_MAXCHILDREN) { 954 message = "hub has too many ports!"; 955 ret = -ENODEV; 956 goto fail; 957 } 958 959 hdev->maxchild = hub->descriptor->bNbrPorts; 960 dev_info (hub_dev, "%d port%s detected\n", hdev->maxchild, 961 (hdev->maxchild == 1) ? "" : "s"); 962 963 hub->port_owners = kzalloc(hdev->maxchild * sizeof(void *), GFP_KERNEL); 964 if (!hub->port_owners) { 965 ret = -ENOMEM; 966 goto fail; 967 } 968 969 wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics); 970 971 if (wHubCharacteristics & HUB_CHAR_COMPOUND) { 972 int i; 973 char portstr [USB_MAXCHILDREN + 1]; 974 975 for (i = 0; i < hdev->maxchild; i++) 976 portstr[i] = hub->descriptor->DeviceRemovable 977 [((i + 1) / 8)] & (1 << ((i + 1) % 8)) 978 ? 'F' : 'R'; 979 portstr[hdev->maxchild] = 0; 980 dev_dbg(hub_dev, "compound device; port removable status: %s\n", portstr); 981 } else 982 dev_dbg(hub_dev, "standalone hub\n"); 983 984 switch (wHubCharacteristics & HUB_CHAR_LPSM) { 985 case 0x00: 986 dev_dbg(hub_dev, "ganged power switching\n"); 987 break; 988 case 0x01: 989 dev_dbg(hub_dev, "individual port power switching\n"); 990 break; 991 case 0x02: 992 case 0x03: 993 dev_dbg(hub_dev, "no power switching (usb 1.0)\n"); 994 break; 995 } 996 997 switch (wHubCharacteristics & HUB_CHAR_OCPM) { 998 case 0x00: 999 dev_dbg(hub_dev, "global over-current protection\n"); 1000 break; 1001 case 0x08: 1002 dev_dbg(hub_dev, "individual port over-current protection\n"); 1003 break; 1004 case 0x10: 1005 case 0x18: 1006 dev_dbg(hub_dev, "no over-current protection\n"); 1007 break; 1008 } 1009 1010 spin_lock_init (&hub->tt.lock); 1011 INIT_LIST_HEAD (&hub->tt.clear_list); 1012 INIT_WORK(&hub->tt.clear_work, hub_tt_work); 1013 switch (hdev->descriptor.bDeviceProtocol) { 1014 case 0: 1015 break; 1016 case 1: 1017 dev_dbg(hub_dev, "Single TT\n"); 1018 hub->tt.hub = hdev; 1019 break; 1020 case 2: 1021 ret = usb_set_interface(hdev, 0, 1); 1022 if (ret == 0) { 1023 dev_dbg(hub_dev, "TT per port\n"); 1024 hub->tt.multi = 1; 1025 } else 1026 dev_err(hub_dev, "Using single TT (err %d)\n", 1027 ret); 1028 hub->tt.hub = hdev; 1029 break; 1030 case 3: 1031 /* USB 3.0 hubs don't have a TT */ 1032 break; 1033 default: 1034 dev_dbg(hub_dev, "Unrecognized hub protocol %d\n", 1035 hdev->descriptor.bDeviceProtocol); 1036 break; 1037 } 1038 1039 /* Note 8 FS bit times == (8 bits / 12000000 bps) ~= 666ns */ 1040 switch (wHubCharacteristics & HUB_CHAR_TTTT) { 1041 case HUB_TTTT_8_BITS: 1042 if (hdev->descriptor.bDeviceProtocol != 0) { 1043 hub->tt.think_time = 666; 1044 dev_dbg(hub_dev, "TT requires at most %d " 1045 "FS bit times (%d ns)\n", 1046 8, hub->tt.think_time); 1047 } 1048 break; 1049 case HUB_TTTT_16_BITS: 1050 hub->tt.think_time = 666 * 2; 1051 dev_dbg(hub_dev, "TT requires at most %d " 1052 "FS bit times (%d ns)\n", 1053 16, hub->tt.think_time); 1054 break; 1055 case HUB_TTTT_24_BITS: 1056 hub->tt.think_time = 666 * 3; 1057 dev_dbg(hub_dev, "TT requires at most %d " 1058 "FS bit times (%d ns)\n", 1059 24, hub->tt.think_time); 1060 break; 1061 case HUB_TTTT_32_BITS: 1062 hub->tt.think_time = 666 * 4; 1063 dev_dbg(hub_dev, "TT requires at most %d " 1064 "FS bit times (%d ns)\n", 1065 32, hub->tt.think_time); 1066 break; 1067 } 1068 1069 /* probe() zeroes hub->indicator[] */ 1070 if (wHubCharacteristics & HUB_CHAR_PORTIND) { 1071 hub->has_indicators = 1; 1072 dev_dbg(hub_dev, "Port indicators are supported\n"); 1073 } 1074 1075 dev_dbg(hub_dev, "power on to power good time: %dms\n", 1076 hub->descriptor->bPwrOn2PwrGood * 2); 1077 1078 /* power budgeting mostly matters with bus-powered hubs, 1079 * and battery-powered root hubs (may provide just 8 mA). 1080 */ 1081 ret = usb_get_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus); 1082 if (ret < 2) { 1083 message = "can't get hub status"; 1084 goto fail; 1085 } 1086 le16_to_cpus(&hubstatus); 1087 if (hdev == hdev->bus->root_hub) { 1088 if (hdev->bus_mA == 0 || hdev->bus_mA >= 500) 1089 hub->mA_per_port = 500; 1090 else { 1091 hub->mA_per_port = hdev->bus_mA; 1092 hub->limited_power = 1; 1093 } 1094 } else if ((hubstatus & (1 << USB_DEVICE_SELF_POWERED)) == 0) { 1095 dev_dbg(hub_dev, "hub controller current requirement: %dmA\n", 1096 hub->descriptor->bHubContrCurrent); 1097 hub->limited_power = 1; 1098 if (hdev->maxchild > 0) { 1099 int remaining = hdev->bus_mA - 1100 hub->descriptor->bHubContrCurrent; 1101 1102 if (remaining < hdev->maxchild * 100) 1103 dev_warn(hub_dev, 1104 "insufficient power available " 1105 "to use all downstream ports\n"); 1106 hub->mA_per_port = 100; /* 7.2.1.1 */ 1107 } 1108 } else { /* Self-powered external hub */ 1109 /* FIXME: What about battery-powered external hubs that 1110 * provide less current per port? */ 1111 hub->mA_per_port = 500; 1112 } 1113 if (hub->mA_per_port < 500) 1114 dev_dbg(hub_dev, "%umA bus power budget for each child\n", 1115 hub->mA_per_port); 1116 1117 /* Update the HCD's internal representation of this hub before khubd 1118 * starts getting port status changes for devices under the hub. 1119 */ 1120 hcd = bus_to_hcd(hdev->bus); 1121 if (hcd->driver->update_hub_device) { 1122 ret = hcd->driver->update_hub_device(hcd, hdev, 1123 &hub->tt, GFP_KERNEL); 1124 if (ret < 0) { 1125 message = "can't update HCD hub info"; 1126 goto fail; 1127 } 1128 } 1129 1130 ret = hub_hub_status(hub, &hubstatus, &hubchange); 1131 if (ret < 0) { 1132 message = "can't get hub status"; 1133 goto fail; 1134 } 1135 1136 /* local power status reports aren't always correct */ 1137 if (hdev->actconfig->desc.bmAttributes & USB_CONFIG_ATT_SELFPOWER) 1138 dev_dbg(hub_dev, "local power source is %s\n", 1139 (hubstatus & HUB_STATUS_LOCAL_POWER) 1140 ? "lost (inactive)" : "good"); 1141 1142 if ((wHubCharacteristics & HUB_CHAR_OCPM) == 0) 1143 dev_dbg(hub_dev, "%sover-current condition exists\n", 1144 (hubstatus & HUB_STATUS_OVERCURRENT) ? "" : "no "); 1145 1146 /* set up the interrupt endpoint 1147 * We use the EP's maxpacket size instead of (PORTS+1+7)/8 1148 * bytes as USB2.0[11.12.3] says because some hubs are known 1149 * to send more data (and thus cause overflow). For root hubs, 1150 * maxpktsize is defined in hcd.c's fake endpoint descriptors 1151 * to be big enough for at least USB_MAXCHILDREN ports. */ 1152 pipe = usb_rcvintpipe(hdev, endpoint->bEndpointAddress); 1153 maxp = usb_maxpacket(hdev, pipe, usb_pipeout(pipe)); 1154 1155 if (maxp > sizeof(*hub->buffer)) 1156 maxp = sizeof(*hub->buffer); 1157 1158 hub->urb = usb_alloc_urb(0, GFP_KERNEL); 1159 if (!hub->urb) { 1160 ret = -ENOMEM; 1161 goto fail; 1162 } 1163 1164 usb_fill_int_urb(hub->urb, hdev, pipe, *hub->buffer, maxp, hub_irq, 1165 hub, endpoint->bInterval); 1166 1167 /* maybe cycle the hub leds */ 1168 if (hub->has_indicators && blinkenlights) 1169 hub->indicator [0] = INDICATOR_CYCLE; 1170 1171 hub_activate(hub, HUB_INIT); 1172 return 0; 1173 1174 fail: 1175 dev_err (hub_dev, "config failed, %s (err %d)\n", 1176 message, ret); 1177 /* hub_disconnect() frees urb and descriptor */ 1178 return ret; 1179 } 1180 1181 static void hub_release(struct kref *kref) 1182 { 1183 struct usb_hub *hub = container_of(kref, struct usb_hub, kref); 1184 1185 usb_put_intf(to_usb_interface(hub->intfdev)); 1186 kfree(hub); 1187 } 1188 1189 static unsigned highspeed_hubs; 1190 1191 static void hub_disconnect(struct usb_interface *intf) 1192 { 1193 struct usb_hub *hub = usb_get_intfdata (intf); 1194 1195 /* Take the hub off the event list and don't let it be added again */ 1196 spin_lock_irq(&hub_event_lock); 1197 if (!list_empty(&hub->event_list)) { 1198 list_del_init(&hub->event_list); 1199 usb_autopm_put_interface_no_suspend(intf); 1200 } 1201 hub->disconnected = 1; 1202 spin_unlock_irq(&hub_event_lock); 1203 1204 /* Disconnect all children and quiesce the hub */ 1205 hub->error = 0; 1206 hub_quiesce(hub, HUB_DISCONNECT); 1207 1208 usb_set_intfdata (intf, NULL); 1209 hub->hdev->maxchild = 0; 1210 1211 if (hub->hdev->speed == USB_SPEED_HIGH) 1212 highspeed_hubs--; 1213 1214 usb_free_urb(hub->urb); 1215 kfree(hub->port_owners); 1216 kfree(hub->descriptor); 1217 kfree(hub->status); 1218 kfree(hub->buffer); 1219 1220 kref_put(&hub->kref, hub_release); 1221 } 1222 1223 static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id) 1224 { 1225 struct usb_host_interface *desc; 1226 struct usb_endpoint_descriptor *endpoint; 1227 struct usb_device *hdev; 1228 struct usb_hub *hub; 1229 1230 desc = intf->cur_altsetting; 1231 hdev = interface_to_usbdev(intf); 1232 1233 /* Hubs have proper suspend/resume support */ 1234 usb_enable_autosuspend(hdev); 1235 1236 if (hdev->level == MAX_TOPO_LEVEL) { 1237 dev_err(&intf->dev, 1238 "Unsupported bus topology: hub nested too deep\n"); 1239 return -E2BIG; 1240 } 1241 1242 #ifdef CONFIG_USB_OTG_BLACKLIST_HUB 1243 if (hdev->parent) { 1244 dev_warn(&intf->dev, "ignoring external hub\n"); 1245 return -ENODEV; 1246 } 1247 #endif 1248 1249 /* Some hubs have a subclass of 1, which AFAICT according to the */ 1250 /* specs is not defined, but it works */ 1251 if ((desc->desc.bInterfaceSubClass != 0) && 1252 (desc->desc.bInterfaceSubClass != 1)) { 1253 descriptor_error: 1254 dev_err (&intf->dev, "bad descriptor, ignoring hub\n"); 1255 return -EIO; 1256 } 1257 1258 /* Multiple endpoints? What kind of mutant ninja-hub is this? */ 1259 if (desc->desc.bNumEndpoints != 1) 1260 goto descriptor_error; 1261 1262 endpoint = &desc->endpoint[0].desc; 1263 1264 /* If it's not an interrupt in endpoint, we'd better punt! */ 1265 if (!usb_endpoint_is_int_in(endpoint)) 1266 goto descriptor_error; 1267 1268 /* We found a hub */ 1269 dev_info (&intf->dev, "USB hub found\n"); 1270 1271 hub = kzalloc(sizeof(*hub), GFP_KERNEL); 1272 if (!hub) { 1273 dev_dbg (&intf->dev, "couldn't kmalloc hub struct\n"); 1274 return -ENOMEM; 1275 } 1276 1277 kref_init(&hub->kref); 1278 INIT_LIST_HEAD(&hub->event_list); 1279 hub->intfdev = &intf->dev; 1280 hub->hdev = hdev; 1281 INIT_DELAYED_WORK(&hub->leds, led_work); 1282 INIT_DELAYED_WORK(&hub->init_work, NULL); 1283 usb_get_intf(intf); 1284 1285 usb_set_intfdata (intf, hub); 1286 intf->needs_remote_wakeup = 1; 1287 1288 if (hdev->speed == USB_SPEED_HIGH) 1289 highspeed_hubs++; 1290 1291 if (hub_configure(hub, endpoint) >= 0) 1292 return 0; 1293 1294 hub_disconnect (intf); 1295 return -ENODEV; 1296 } 1297 1298 /* No BKL needed */ 1299 static int 1300 hub_ioctl(struct usb_interface *intf, unsigned int code, void *user_data) 1301 { 1302 struct usb_device *hdev = interface_to_usbdev (intf); 1303 1304 /* assert ifno == 0 (part of hub spec) */ 1305 switch (code) { 1306 case USBDEVFS_HUB_PORTINFO: { 1307 struct usbdevfs_hub_portinfo *info = user_data; 1308 int i; 1309 1310 spin_lock_irq(&device_state_lock); 1311 if (hdev->devnum <= 0) 1312 info->nports = 0; 1313 else { 1314 info->nports = hdev->maxchild; 1315 for (i = 0; i < info->nports; i++) { 1316 if (hdev->children[i] == NULL) 1317 info->port[i] = 0; 1318 else 1319 info->port[i] = 1320 hdev->children[i]->devnum; 1321 } 1322 } 1323 spin_unlock_irq(&device_state_lock); 1324 1325 return info->nports + 1; 1326 } 1327 1328 default: 1329 return -ENOSYS; 1330 } 1331 } 1332 1333 /* 1334 * Allow user programs to claim ports on a hub. When a device is attached 1335 * to one of these "claimed" ports, the program will "own" the device. 1336 */ 1337 static int find_port_owner(struct usb_device *hdev, unsigned port1, 1338 void ***ppowner) 1339 { 1340 if (hdev->state == USB_STATE_NOTATTACHED) 1341 return -ENODEV; 1342 if (port1 == 0 || port1 > hdev->maxchild) 1343 return -EINVAL; 1344 1345 /* This assumes that devices not managed by the hub driver 1346 * will always have maxchild equal to 0. 1347 */ 1348 *ppowner = &(hdev_to_hub(hdev)->port_owners[port1 - 1]); 1349 return 0; 1350 } 1351 1352 /* In the following three functions, the caller must hold hdev's lock */ 1353 int usb_hub_claim_port(struct usb_device *hdev, unsigned port1, void *owner) 1354 { 1355 int rc; 1356 void **powner; 1357 1358 rc = find_port_owner(hdev, port1, &powner); 1359 if (rc) 1360 return rc; 1361 if (*powner) 1362 return -EBUSY; 1363 *powner = owner; 1364 return rc; 1365 } 1366 1367 int usb_hub_release_port(struct usb_device *hdev, unsigned port1, void *owner) 1368 { 1369 int rc; 1370 void **powner; 1371 1372 rc = find_port_owner(hdev, port1, &powner); 1373 if (rc) 1374 return rc; 1375 if (*powner != owner) 1376 return -ENOENT; 1377 *powner = NULL; 1378 return rc; 1379 } 1380 1381 void usb_hub_release_all_ports(struct usb_device *hdev, void *owner) 1382 { 1383 int n; 1384 void **powner; 1385 1386 n = find_port_owner(hdev, 1, &powner); 1387 if (n == 0) { 1388 for (; n < hdev->maxchild; (++n, ++powner)) { 1389 if (*powner == owner) 1390 *powner = NULL; 1391 } 1392 } 1393 } 1394 1395 /* The caller must hold udev's lock */ 1396 bool usb_device_is_owned(struct usb_device *udev) 1397 { 1398 struct usb_hub *hub; 1399 1400 if (udev->state == USB_STATE_NOTATTACHED || !udev->parent) 1401 return false; 1402 hub = hdev_to_hub(udev->parent); 1403 return !!hub->port_owners[udev->portnum - 1]; 1404 } 1405 1406 1407 static void recursively_mark_NOTATTACHED(struct usb_device *udev) 1408 { 1409 int i; 1410 1411 for (i = 0; i < udev->maxchild; ++i) { 1412 if (udev->children[i]) 1413 recursively_mark_NOTATTACHED(udev->children[i]); 1414 } 1415 if (udev->state == USB_STATE_SUSPENDED) 1416 udev->active_duration -= jiffies; 1417 udev->state = USB_STATE_NOTATTACHED; 1418 } 1419 1420 /** 1421 * usb_set_device_state - change a device's current state (usbcore, hcds) 1422 * @udev: pointer to device whose state should be changed 1423 * @new_state: new state value to be stored 1424 * 1425 * udev->state is _not_ fully protected by the device lock. Although 1426 * most transitions are made only while holding the lock, the state can 1427 * can change to USB_STATE_NOTATTACHED at almost any time. This 1428 * is so that devices can be marked as disconnected as soon as possible, 1429 * without having to wait for any semaphores to be released. As a result, 1430 * all changes to any device's state must be protected by the 1431 * device_state_lock spinlock. 1432 * 1433 * Once a device has been added to the device tree, all changes to its state 1434 * should be made using this routine. The state should _not_ be set directly. 1435 * 1436 * If udev->state is already USB_STATE_NOTATTACHED then no change is made. 1437 * Otherwise udev->state is set to new_state, and if new_state is 1438 * USB_STATE_NOTATTACHED then all of udev's descendants' states are also set 1439 * to USB_STATE_NOTATTACHED. 1440 */ 1441 void usb_set_device_state(struct usb_device *udev, 1442 enum usb_device_state new_state) 1443 { 1444 unsigned long flags; 1445 1446 spin_lock_irqsave(&device_state_lock, flags); 1447 if (udev->state == USB_STATE_NOTATTACHED) 1448 ; /* do nothing */ 1449 else if (new_state != USB_STATE_NOTATTACHED) { 1450 1451 /* root hub wakeup capabilities are managed out-of-band 1452 * and may involve silicon errata ... ignore them here. 1453 */ 1454 if (udev->parent) { 1455 if (udev->state == USB_STATE_SUSPENDED 1456 || new_state == USB_STATE_SUSPENDED) 1457 ; /* No change to wakeup settings */ 1458 else if (new_state == USB_STATE_CONFIGURED) 1459 device_set_wakeup_capable(&udev->dev, 1460 (udev->actconfig->desc.bmAttributes 1461 & USB_CONFIG_ATT_WAKEUP)); 1462 else 1463 device_set_wakeup_capable(&udev->dev, 0); 1464 } 1465 if (udev->state == USB_STATE_SUSPENDED && 1466 new_state != USB_STATE_SUSPENDED) 1467 udev->active_duration -= jiffies; 1468 else if (new_state == USB_STATE_SUSPENDED && 1469 udev->state != USB_STATE_SUSPENDED) 1470 udev->active_duration += jiffies; 1471 udev->state = new_state; 1472 } else 1473 recursively_mark_NOTATTACHED(udev); 1474 spin_unlock_irqrestore(&device_state_lock, flags); 1475 } 1476 EXPORT_SYMBOL_GPL(usb_set_device_state); 1477 1478 /* 1479 * WUSB devices are simple: they have no hubs behind, so the mapping 1480 * device <-> virtual port number becomes 1:1. Why? to simplify the 1481 * life of the device connection logic in 1482 * drivers/usb/wusbcore/devconnect.c. When we do the initial secret 1483 * handshake we need to assign a temporary address in the unauthorized 1484 * space. For simplicity we use the first virtual port number found to 1485 * be free [drivers/usb/wusbcore/devconnect.c:wusbhc_devconnect_ack()] 1486 * and that becomes it's address [X < 128] or its unauthorized address 1487 * [X | 0x80]. 1488 * 1489 * We add 1 as an offset to the one-based USB-stack port number 1490 * (zero-based wusb virtual port index) for two reasons: (a) dev addr 1491 * 0 is reserved by USB for default address; (b) Linux's USB stack 1492 * uses always #1 for the root hub of the controller. So USB stack's 1493 * port #1, which is wusb virtual-port #0 has address #2. 1494 * 1495 * Devices connected under xHCI are not as simple. The host controller 1496 * supports virtualization, so the hardware assigns device addresses and 1497 * the HCD must setup data structures before issuing a set address 1498 * command to the hardware. 1499 */ 1500 static void choose_address(struct usb_device *udev) 1501 { 1502 int devnum; 1503 struct usb_bus *bus = udev->bus; 1504 1505 /* If khubd ever becomes multithreaded, this will need a lock */ 1506 if (udev->wusb) { 1507 devnum = udev->portnum + 1; 1508 BUG_ON(test_bit(devnum, bus->devmap.devicemap)); 1509 } else { 1510 /* Try to allocate the next devnum beginning at 1511 * bus->devnum_next. */ 1512 devnum = find_next_zero_bit(bus->devmap.devicemap, 128, 1513 bus->devnum_next); 1514 if (devnum >= 128) 1515 devnum = find_next_zero_bit(bus->devmap.devicemap, 1516 128, 1); 1517 bus->devnum_next = ( devnum >= 127 ? 1 : devnum + 1); 1518 } 1519 if (devnum < 128) { 1520 set_bit(devnum, bus->devmap.devicemap); 1521 udev->devnum = devnum; 1522 } 1523 } 1524 1525 static void release_address(struct usb_device *udev) 1526 { 1527 if (udev->devnum > 0) { 1528 clear_bit(udev->devnum, udev->bus->devmap.devicemap); 1529 udev->devnum = -1; 1530 } 1531 } 1532 1533 static void update_address(struct usb_device *udev, int devnum) 1534 { 1535 /* The address for a WUSB device is managed by wusbcore. */ 1536 if (!udev->wusb) 1537 udev->devnum = devnum; 1538 } 1539 1540 static void hub_free_dev(struct usb_device *udev) 1541 { 1542 struct usb_hcd *hcd = bus_to_hcd(udev->bus); 1543 1544 /* Root hubs aren't real devices, so don't free HCD resources */ 1545 if (hcd->driver->free_dev && udev->parent) 1546 hcd->driver->free_dev(hcd, udev); 1547 } 1548 1549 /** 1550 * usb_disconnect - disconnect a device (usbcore-internal) 1551 * @pdev: pointer to device being disconnected 1552 * Context: !in_interrupt () 1553 * 1554 * Something got disconnected. Get rid of it and all of its children. 1555 * 1556 * If *pdev is a normal device then the parent hub must already be locked. 1557 * If *pdev is a root hub then this routine will acquire the 1558 * usb_bus_list_lock on behalf of the caller. 1559 * 1560 * Only hub drivers (including virtual root hub drivers for host 1561 * controllers) should ever call this. 1562 * 1563 * This call is synchronous, and may not be used in an interrupt context. 1564 */ 1565 void usb_disconnect(struct usb_device **pdev) 1566 { 1567 struct usb_device *udev = *pdev; 1568 int i; 1569 1570 if (!udev) { 1571 pr_debug ("%s nodev\n", __func__); 1572 return; 1573 } 1574 1575 /* mark the device as inactive, so any further urb submissions for 1576 * this device (and any of its children) will fail immediately. 1577 * this quiesces everyting except pending urbs. 1578 */ 1579 usb_set_device_state(udev, USB_STATE_NOTATTACHED); 1580 dev_info (&udev->dev, "USB disconnect, address %d\n", udev->devnum); 1581 1582 usb_lock_device(udev); 1583 1584 /* Free up all the children before we remove this device */ 1585 for (i = 0; i < USB_MAXCHILDREN; i++) { 1586 if (udev->children[i]) 1587 usb_disconnect(&udev->children[i]); 1588 } 1589 1590 /* deallocate hcd/hardware state ... nuking all pending urbs and 1591 * cleaning up all state associated with the current configuration 1592 * so that the hardware is now fully quiesced. 1593 */ 1594 dev_dbg (&udev->dev, "unregistering device\n"); 1595 usb_disable_device(udev, 0); 1596 usb_hcd_synchronize_unlinks(udev); 1597 1598 usb_remove_ep_devs(&udev->ep0); 1599 usb_unlock_device(udev); 1600 1601 /* Unregister the device. The device driver is responsible 1602 * for de-configuring the device and invoking the remove-device 1603 * notifier chain (used by usbfs and possibly others). 1604 */ 1605 device_del(&udev->dev); 1606 1607 /* Free the device number and delete the parent's children[] 1608 * (or root_hub) pointer. 1609 */ 1610 release_address(udev); 1611 1612 /* Avoid races with recursively_mark_NOTATTACHED() */ 1613 spin_lock_irq(&device_state_lock); 1614 *pdev = NULL; 1615 spin_unlock_irq(&device_state_lock); 1616 1617 hub_free_dev(udev); 1618 1619 put_device(&udev->dev); 1620 } 1621 1622 #ifdef CONFIG_USB_ANNOUNCE_NEW_DEVICES 1623 static void show_string(struct usb_device *udev, char *id, char *string) 1624 { 1625 if (!string) 1626 return; 1627 dev_printk(KERN_INFO, &udev->dev, "%s: %s\n", id, string); 1628 } 1629 1630 static void announce_device(struct usb_device *udev) 1631 { 1632 dev_info(&udev->dev, "New USB device found, idVendor=%04x, idProduct=%04x\n", 1633 le16_to_cpu(udev->descriptor.idVendor), 1634 le16_to_cpu(udev->descriptor.idProduct)); 1635 dev_info(&udev->dev, 1636 "New USB device strings: Mfr=%d, Product=%d, SerialNumber=%d\n", 1637 udev->descriptor.iManufacturer, 1638 udev->descriptor.iProduct, 1639 udev->descriptor.iSerialNumber); 1640 show_string(udev, "Product", udev->product); 1641 show_string(udev, "Manufacturer", udev->manufacturer); 1642 show_string(udev, "SerialNumber", udev->serial); 1643 } 1644 #else 1645 static inline void announce_device(struct usb_device *udev) { } 1646 #endif 1647 1648 #ifdef CONFIG_USB_OTG 1649 #include "otg_whitelist.h" 1650 #endif 1651 1652 /** 1653 * usb_enumerate_device_otg - FIXME (usbcore-internal) 1654 * @udev: newly addressed device (in ADDRESS state) 1655 * 1656 * Finish enumeration for On-The-Go devices 1657 */ 1658 static int usb_enumerate_device_otg(struct usb_device *udev) 1659 { 1660 int err = 0; 1661 1662 #ifdef CONFIG_USB_OTG 1663 /* 1664 * OTG-aware devices on OTG-capable root hubs may be able to use SRP, 1665 * to wake us after we've powered off VBUS; and HNP, switching roles 1666 * "host" to "peripheral". The OTG descriptor helps figure this out. 1667 */ 1668 if (!udev->bus->is_b_host 1669 && udev->config 1670 && udev->parent == udev->bus->root_hub) { 1671 struct usb_otg_descriptor *desc = NULL; 1672 struct usb_bus *bus = udev->bus; 1673 1674 /* descriptor may appear anywhere in config */ 1675 if (__usb_get_extra_descriptor (udev->rawdescriptors[0], 1676 le16_to_cpu(udev->config[0].desc.wTotalLength), 1677 USB_DT_OTG, (void **) &desc) == 0) { 1678 if (desc->bmAttributes & USB_OTG_HNP) { 1679 unsigned port1 = udev->portnum; 1680 1681 dev_info(&udev->dev, 1682 "Dual-Role OTG device on %sHNP port\n", 1683 (port1 == bus->otg_port) 1684 ? "" : "non-"); 1685 1686 /* enable HNP before suspend, it's simpler */ 1687 if (port1 == bus->otg_port) 1688 bus->b_hnp_enable = 1; 1689 err = usb_control_msg(udev, 1690 usb_sndctrlpipe(udev, 0), 1691 USB_REQ_SET_FEATURE, 0, 1692 bus->b_hnp_enable 1693 ? USB_DEVICE_B_HNP_ENABLE 1694 : USB_DEVICE_A_ALT_HNP_SUPPORT, 1695 0, NULL, 0, USB_CTRL_SET_TIMEOUT); 1696 if (err < 0) { 1697 /* OTG MESSAGE: report errors here, 1698 * customize to match your product. 1699 */ 1700 dev_info(&udev->dev, 1701 "can't set HNP mode: %d\n", 1702 err); 1703 bus->b_hnp_enable = 0; 1704 } 1705 } 1706 } 1707 } 1708 1709 if (!is_targeted(udev)) { 1710 1711 /* Maybe it can talk to us, though we can't talk to it. 1712 * (Includes HNP test device.) 1713 */ 1714 if (udev->bus->b_hnp_enable || udev->bus->is_b_host) { 1715 err = usb_port_suspend(udev, PMSG_SUSPEND); 1716 if (err < 0) 1717 dev_dbg(&udev->dev, "HNP fail, %d\n", err); 1718 } 1719 err = -ENOTSUPP; 1720 goto fail; 1721 } 1722 fail: 1723 #endif 1724 return err; 1725 } 1726 1727 1728 /** 1729 * usb_enumerate_device - Read device configs/intfs/otg (usbcore-internal) 1730 * @udev: newly addressed device (in ADDRESS state) 1731 * 1732 * This is only called by usb_new_device() and usb_authorize_device() 1733 * and FIXME -- all comments that apply to them apply here wrt to 1734 * environment. 1735 * 1736 * If the device is WUSB and not authorized, we don't attempt to read 1737 * the string descriptors, as they will be errored out by the device 1738 * until it has been authorized. 1739 */ 1740 static int usb_enumerate_device(struct usb_device *udev) 1741 { 1742 int err; 1743 1744 if (udev->config == NULL) { 1745 err = usb_get_configuration(udev); 1746 if (err < 0) { 1747 dev_err(&udev->dev, "can't read configurations, error %d\n", 1748 err); 1749 goto fail; 1750 } 1751 } 1752 if (udev->wusb == 1 && udev->authorized == 0) { 1753 udev->product = kstrdup("n/a (unauthorized)", GFP_KERNEL); 1754 udev->manufacturer = kstrdup("n/a (unauthorized)", GFP_KERNEL); 1755 udev->serial = kstrdup("n/a (unauthorized)", GFP_KERNEL); 1756 } 1757 else { 1758 /* read the standard strings and cache them if present */ 1759 udev->product = usb_cache_string(udev, udev->descriptor.iProduct); 1760 udev->manufacturer = usb_cache_string(udev, 1761 udev->descriptor.iManufacturer); 1762 udev->serial = usb_cache_string(udev, udev->descriptor.iSerialNumber); 1763 } 1764 err = usb_enumerate_device_otg(udev); 1765 fail: 1766 return err; 1767 } 1768 1769 1770 /** 1771 * usb_new_device - perform initial device setup (usbcore-internal) 1772 * @udev: newly addressed device (in ADDRESS state) 1773 * 1774 * This is called with devices which have been detected but not fully 1775 * enumerated. The device descriptor is available, but not descriptors 1776 * for any device configuration. The caller must have locked either 1777 * the parent hub (if udev is a normal device) or else the 1778 * usb_bus_list_lock (if udev is a root hub). The parent's pointer to 1779 * udev has already been installed, but udev is not yet visible through 1780 * sysfs or other filesystem code. 1781 * 1782 * It will return if the device is configured properly or not. Zero if 1783 * the interface was registered with the driver core; else a negative 1784 * errno value. 1785 * 1786 * This call is synchronous, and may not be used in an interrupt context. 1787 * 1788 * Only the hub driver or root-hub registrar should ever call this. 1789 */ 1790 int usb_new_device(struct usb_device *udev) 1791 { 1792 int err; 1793 1794 if (udev->parent) { 1795 /* Initialize non-root-hub device wakeup to disabled; 1796 * device (un)configuration controls wakeup capable 1797 * sysfs power/wakeup controls wakeup enabled/disabled 1798 */ 1799 device_init_wakeup(&udev->dev, 0); 1800 } 1801 1802 /* Tell the runtime-PM framework the device is active */ 1803 pm_runtime_set_active(&udev->dev); 1804 pm_runtime_enable(&udev->dev); 1805 1806 err = usb_enumerate_device(udev); /* Read descriptors */ 1807 if (err < 0) 1808 goto fail; 1809 dev_dbg(&udev->dev, "udev %d, busnum %d, minor = %d\n", 1810 udev->devnum, udev->bus->busnum, 1811 (((udev->bus->busnum-1) * 128) + (udev->devnum-1))); 1812 /* export the usbdev device-node for libusb */ 1813 udev->dev.devt = MKDEV(USB_DEVICE_MAJOR, 1814 (((udev->bus->busnum-1) * 128) + (udev->devnum-1))); 1815 1816 /* Tell the world! */ 1817 announce_device(udev); 1818 1819 device_enable_async_suspend(&udev->dev); 1820 /* Register the device. The device driver is responsible 1821 * for configuring the device and invoking the add-device 1822 * notifier chain (used by usbfs and possibly others). 1823 */ 1824 err = device_add(&udev->dev); 1825 if (err) { 1826 dev_err(&udev->dev, "can't device_add, error %d\n", err); 1827 goto fail; 1828 } 1829 1830 (void) usb_create_ep_devs(&udev->dev, &udev->ep0, udev); 1831 return err; 1832 1833 fail: 1834 usb_set_device_state(udev, USB_STATE_NOTATTACHED); 1835 pm_runtime_disable(&udev->dev); 1836 pm_runtime_set_suspended(&udev->dev); 1837 return err; 1838 } 1839 1840 1841 /** 1842 * usb_deauthorize_device - deauthorize a device (usbcore-internal) 1843 * @usb_dev: USB device 1844 * 1845 * Move the USB device to a very basic state where interfaces are disabled 1846 * and the device is in fact unconfigured and unusable. 1847 * 1848 * We share a lock (that we have) with device_del(), so we need to 1849 * defer its call. 1850 */ 1851 int usb_deauthorize_device(struct usb_device *usb_dev) 1852 { 1853 usb_lock_device(usb_dev); 1854 if (usb_dev->authorized == 0) 1855 goto out_unauthorized; 1856 1857 usb_dev->authorized = 0; 1858 usb_set_configuration(usb_dev, -1); 1859 1860 kfree(usb_dev->product); 1861 usb_dev->product = kstrdup("n/a (unauthorized)", GFP_KERNEL); 1862 kfree(usb_dev->manufacturer); 1863 usb_dev->manufacturer = kstrdup("n/a (unauthorized)", GFP_KERNEL); 1864 kfree(usb_dev->serial); 1865 usb_dev->serial = kstrdup("n/a (unauthorized)", GFP_KERNEL); 1866 1867 usb_destroy_configuration(usb_dev); 1868 usb_dev->descriptor.bNumConfigurations = 0; 1869 1870 out_unauthorized: 1871 usb_unlock_device(usb_dev); 1872 return 0; 1873 } 1874 1875 1876 int usb_authorize_device(struct usb_device *usb_dev) 1877 { 1878 int result = 0, c; 1879 1880 usb_lock_device(usb_dev); 1881 if (usb_dev->authorized == 1) 1882 goto out_authorized; 1883 1884 result = usb_autoresume_device(usb_dev); 1885 if (result < 0) { 1886 dev_err(&usb_dev->dev, 1887 "can't autoresume for authorization: %d\n", result); 1888 goto error_autoresume; 1889 } 1890 result = usb_get_device_descriptor(usb_dev, sizeof(usb_dev->descriptor)); 1891 if (result < 0) { 1892 dev_err(&usb_dev->dev, "can't re-read device descriptor for " 1893 "authorization: %d\n", result); 1894 goto error_device_descriptor; 1895 } 1896 1897 kfree(usb_dev->product); 1898 usb_dev->product = NULL; 1899 kfree(usb_dev->manufacturer); 1900 usb_dev->manufacturer = NULL; 1901 kfree(usb_dev->serial); 1902 usb_dev->serial = NULL; 1903 1904 usb_dev->authorized = 1; 1905 result = usb_enumerate_device(usb_dev); 1906 if (result < 0) 1907 goto error_enumerate; 1908 /* Choose and set the configuration. This registers the interfaces 1909 * with the driver core and lets interface drivers bind to them. 1910 */ 1911 c = usb_choose_configuration(usb_dev); 1912 if (c >= 0) { 1913 result = usb_set_configuration(usb_dev, c); 1914 if (result) { 1915 dev_err(&usb_dev->dev, 1916 "can't set config #%d, error %d\n", c, result); 1917 /* This need not be fatal. The user can try to 1918 * set other configurations. */ 1919 } 1920 } 1921 dev_info(&usb_dev->dev, "authorized to connect\n"); 1922 1923 error_enumerate: 1924 error_device_descriptor: 1925 usb_autosuspend_device(usb_dev); 1926 error_autoresume: 1927 out_authorized: 1928 usb_unlock_device(usb_dev); // complements locktree 1929 return result; 1930 } 1931 1932 1933 /* Returns 1 if @hub is a WUSB root hub, 0 otherwise */ 1934 static unsigned hub_is_wusb(struct usb_hub *hub) 1935 { 1936 struct usb_hcd *hcd; 1937 if (hub->hdev->parent != NULL) /* not a root hub? */ 1938 return 0; 1939 hcd = container_of(hub->hdev->bus, struct usb_hcd, self); 1940 return hcd->wireless; 1941 } 1942 1943 1944 #define PORT_RESET_TRIES 5 1945 #define SET_ADDRESS_TRIES 2 1946 #define GET_DESCRIPTOR_TRIES 2 1947 #define SET_CONFIG_TRIES (2 * (use_both_schemes + 1)) 1948 #define USE_NEW_SCHEME(i) ((i) / 2 == old_scheme_first) 1949 1950 #define HUB_ROOT_RESET_TIME 50 /* times are in msec */ 1951 #define HUB_SHORT_RESET_TIME 10 1952 #define HUB_LONG_RESET_TIME 200 1953 #define HUB_RESET_TIMEOUT 500 1954 1955 static int hub_port_wait_reset(struct usb_hub *hub, int port1, 1956 struct usb_device *udev, unsigned int delay) 1957 { 1958 int delay_time, ret; 1959 u16 portstatus; 1960 u16 portchange; 1961 1962 for (delay_time = 0; 1963 delay_time < HUB_RESET_TIMEOUT; 1964 delay_time += delay) { 1965 /* wait to give the device a chance to reset */ 1966 msleep(delay); 1967 1968 /* read and decode port status */ 1969 ret = hub_port_status(hub, port1, &portstatus, &portchange); 1970 if (ret < 0) 1971 return ret; 1972 1973 /* Device went away? */ 1974 if (!(portstatus & USB_PORT_STAT_CONNECTION)) 1975 return -ENOTCONN; 1976 1977 /* bomb out completely if the connection bounced */ 1978 if ((portchange & USB_PORT_STAT_C_CONNECTION)) 1979 return -ENOTCONN; 1980 1981 /* if we`ve finished resetting, then break out of the loop */ 1982 if (!(portstatus & USB_PORT_STAT_RESET) && 1983 (portstatus & USB_PORT_STAT_ENABLE)) { 1984 if (hub_is_wusb(hub)) 1985 udev->speed = USB_SPEED_WIRELESS; 1986 else if (portstatus & USB_PORT_STAT_SUPER_SPEED) 1987 udev->speed = USB_SPEED_SUPER; 1988 else if (portstatus & USB_PORT_STAT_HIGH_SPEED) 1989 udev->speed = USB_SPEED_HIGH; 1990 else if (portstatus & USB_PORT_STAT_LOW_SPEED) 1991 udev->speed = USB_SPEED_LOW; 1992 else 1993 udev->speed = USB_SPEED_FULL; 1994 return 0; 1995 } 1996 1997 /* switch to the long delay after two short delay failures */ 1998 if (delay_time >= 2 * HUB_SHORT_RESET_TIME) 1999 delay = HUB_LONG_RESET_TIME; 2000 2001 dev_dbg (hub->intfdev, 2002 "port %d not reset yet, waiting %dms\n", 2003 port1, delay); 2004 } 2005 2006 return -EBUSY; 2007 } 2008 2009 static int hub_port_reset(struct usb_hub *hub, int port1, 2010 struct usb_device *udev, unsigned int delay) 2011 { 2012 int i, status; 2013 struct usb_hcd *hcd; 2014 2015 hcd = bus_to_hcd(udev->bus); 2016 /* Block EHCI CF initialization during the port reset. 2017 * Some companion controllers don't like it when they mix. 2018 */ 2019 down_read(&ehci_cf_port_reset_rwsem); 2020 2021 /* Reset the port */ 2022 for (i = 0; i < PORT_RESET_TRIES; i++) { 2023 status = set_port_feature(hub->hdev, 2024 port1, USB_PORT_FEAT_RESET); 2025 if (status) 2026 dev_err(hub->intfdev, 2027 "cannot reset port %d (err = %d)\n", 2028 port1, status); 2029 else { 2030 status = hub_port_wait_reset(hub, port1, udev, delay); 2031 if (status && status != -ENOTCONN) 2032 dev_dbg(hub->intfdev, 2033 "port_wait_reset: err = %d\n", 2034 status); 2035 } 2036 2037 /* return on disconnect or reset */ 2038 switch (status) { 2039 case 0: 2040 /* TRSTRCY = 10 ms; plus some extra */ 2041 msleep(10 + 40); 2042 update_address(udev, 0); 2043 if (hcd->driver->reset_device) { 2044 status = hcd->driver->reset_device(hcd, udev); 2045 if (status < 0) { 2046 dev_err(&udev->dev, "Cannot reset " 2047 "HCD device state\n"); 2048 break; 2049 } 2050 } 2051 /* FALL THROUGH */ 2052 case -ENOTCONN: 2053 case -ENODEV: 2054 clear_port_feature(hub->hdev, 2055 port1, USB_PORT_FEAT_C_RESET); 2056 /* FIXME need disconnect() for NOTATTACHED device */ 2057 usb_set_device_state(udev, status 2058 ? USB_STATE_NOTATTACHED 2059 : USB_STATE_DEFAULT); 2060 goto done; 2061 } 2062 2063 dev_dbg (hub->intfdev, 2064 "port %d not enabled, trying reset again...\n", 2065 port1); 2066 delay = HUB_LONG_RESET_TIME; 2067 } 2068 2069 dev_err (hub->intfdev, 2070 "Cannot enable port %i. Maybe the USB cable is bad?\n", 2071 port1); 2072 2073 done: 2074 up_read(&ehci_cf_port_reset_rwsem); 2075 return status; 2076 } 2077 2078 #ifdef CONFIG_PM 2079 2080 #define MASK_BITS (USB_PORT_STAT_POWER | USB_PORT_STAT_CONNECTION | \ 2081 USB_PORT_STAT_SUSPEND) 2082 #define WANT_BITS (USB_PORT_STAT_POWER | USB_PORT_STAT_CONNECTION) 2083 2084 /* Determine whether the device on a port is ready for a normal resume, 2085 * is ready for a reset-resume, or should be disconnected. 2086 */ 2087 static int check_port_resume_type(struct usb_device *udev, 2088 struct usb_hub *hub, int port1, 2089 int status, unsigned portchange, unsigned portstatus) 2090 { 2091 /* Is the device still present? */ 2092 if (status || (portstatus & MASK_BITS) != WANT_BITS) { 2093 if (status >= 0) 2094 status = -ENODEV; 2095 } 2096 2097 /* Can't do a normal resume if the port isn't enabled, 2098 * so try a reset-resume instead. 2099 */ 2100 else if (!(portstatus & USB_PORT_STAT_ENABLE) && !udev->reset_resume) { 2101 if (udev->persist_enabled) 2102 udev->reset_resume = 1; 2103 else 2104 status = -ENODEV; 2105 } 2106 2107 if (status) { 2108 dev_dbg(hub->intfdev, 2109 "port %d status %04x.%04x after resume, %d\n", 2110 port1, portchange, portstatus, status); 2111 } else if (udev->reset_resume) { 2112 2113 /* Late port handoff can set status-change bits */ 2114 if (portchange & USB_PORT_STAT_C_CONNECTION) 2115 clear_port_feature(hub->hdev, port1, 2116 USB_PORT_FEAT_C_CONNECTION); 2117 if (portchange & USB_PORT_STAT_C_ENABLE) 2118 clear_port_feature(hub->hdev, port1, 2119 USB_PORT_FEAT_C_ENABLE); 2120 } 2121 2122 return status; 2123 } 2124 2125 #ifdef CONFIG_USB_SUSPEND 2126 2127 /* 2128 * usb_port_suspend - suspend a usb device's upstream port 2129 * @udev: device that's no longer in active use, not a root hub 2130 * Context: must be able to sleep; device not locked; pm locks held 2131 * 2132 * Suspends a USB device that isn't in active use, conserving power. 2133 * Devices may wake out of a suspend, if anything important happens, 2134 * using the remote wakeup mechanism. They may also be taken out of 2135 * suspend by the host, using usb_port_resume(). It's also routine 2136 * to disconnect devices while they are suspended. 2137 * 2138 * This only affects the USB hardware for a device; its interfaces 2139 * (and, for hubs, child devices) must already have been suspended. 2140 * 2141 * Selective port suspend reduces power; most suspended devices draw 2142 * less than 500 uA. It's also used in OTG, along with remote wakeup. 2143 * All devices below the suspended port are also suspended. 2144 * 2145 * Devices leave suspend state when the host wakes them up. Some devices 2146 * also support "remote wakeup", where the device can activate the USB 2147 * tree above them to deliver data, such as a keypress or packet. In 2148 * some cases, this wakes the USB host. 2149 * 2150 * Suspending OTG devices may trigger HNP, if that's been enabled 2151 * between a pair of dual-role devices. That will change roles, such 2152 * as from A-Host to A-Peripheral or from B-Host back to B-Peripheral. 2153 * 2154 * Devices on USB hub ports have only one "suspend" state, corresponding 2155 * to ACPI D2, "may cause the device to lose some context". 2156 * State transitions include: 2157 * 2158 * - suspend, resume ... when the VBUS power link stays live 2159 * - suspend, disconnect ... VBUS lost 2160 * 2161 * Once VBUS drop breaks the circuit, the port it's using has to go through 2162 * normal re-enumeration procedures, starting with enabling VBUS power. 2163 * Other than re-initializing the hub (plug/unplug, except for root hubs), 2164 * Linux (2.6) currently has NO mechanisms to initiate that: no khubd 2165 * timer, no SRP, no requests through sysfs. 2166 * 2167 * If CONFIG_USB_SUSPEND isn't enabled, devices only really suspend when 2168 * the root hub for their bus goes into global suspend ... so we don't 2169 * (falsely) update the device power state to say it suspended. 2170 * 2171 * Returns 0 on success, else negative errno. 2172 */ 2173 int usb_port_suspend(struct usb_device *udev, pm_message_t msg) 2174 { 2175 struct usb_hub *hub = hdev_to_hub(udev->parent); 2176 int port1 = udev->portnum; 2177 int status; 2178 2179 // dev_dbg(hub->intfdev, "suspend port %d\n", port1); 2180 2181 /* enable remote wakeup when appropriate; this lets the device 2182 * wake up the upstream hub (including maybe the root hub). 2183 * 2184 * NOTE: OTG devices may issue remote wakeup (or SRP) even when 2185 * we don't explicitly enable it here. 2186 */ 2187 if (udev->do_remote_wakeup) { 2188 status = usb_control_msg(udev, usb_sndctrlpipe(udev, 0), 2189 USB_REQ_SET_FEATURE, USB_RECIP_DEVICE, 2190 USB_DEVICE_REMOTE_WAKEUP, 0, 2191 NULL, 0, 2192 USB_CTRL_SET_TIMEOUT); 2193 if (status) { 2194 dev_dbg(&udev->dev, "won't remote wakeup, status %d\n", 2195 status); 2196 /* bail if autosuspend is requested */ 2197 if (msg.event & PM_EVENT_AUTO) 2198 return status; 2199 } 2200 } 2201 2202 /* see 7.1.7.6 */ 2203 status = set_port_feature(hub->hdev, port1, USB_PORT_FEAT_SUSPEND); 2204 if (status) { 2205 dev_dbg(hub->intfdev, "can't suspend port %d, status %d\n", 2206 port1, status); 2207 /* paranoia: "should not happen" */ 2208 if (udev->do_remote_wakeup) 2209 (void) usb_control_msg(udev, usb_sndctrlpipe(udev, 0), 2210 USB_REQ_CLEAR_FEATURE, USB_RECIP_DEVICE, 2211 USB_DEVICE_REMOTE_WAKEUP, 0, 2212 NULL, 0, 2213 USB_CTRL_SET_TIMEOUT); 2214 } else { 2215 /* device has up to 10 msec to fully suspend */ 2216 dev_dbg(&udev->dev, "usb %ssuspend\n", 2217 (msg.event & PM_EVENT_AUTO ? "auto-" : "")); 2218 usb_set_device_state(udev, USB_STATE_SUSPENDED); 2219 msleep(10); 2220 } 2221 return status; 2222 } 2223 2224 /* 2225 * If the USB "suspend" state is in use (rather than "global suspend"), 2226 * many devices will be individually taken out of suspend state using 2227 * special "resume" signaling. This routine kicks in shortly after 2228 * hardware resume signaling is finished, either because of selective 2229 * resume (by host) or remote wakeup (by device) ... now see what changed 2230 * in the tree that's rooted at this device. 2231 * 2232 * If @udev->reset_resume is set then the device is reset before the 2233 * status check is done. 2234 */ 2235 static int finish_port_resume(struct usb_device *udev) 2236 { 2237 int status = 0; 2238 u16 devstatus; 2239 2240 /* caller owns the udev device lock */ 2241 dev_dbg(&udev->dev, "%s\n", 2242 udev->reset_resume ? "finish reset-resume" : "finish resume"); 2243 2244 /* usb ch9 identifies four variants of SUSPENDED, based on what 2245 * state the device resumes to. Linux currently won't see the 2246 * first two on the host side; they'd be inside hub_port_init() 2247 * during many timeouts, but khubd can't suspend until later. 2248 */ 2249 usb_set_device_state(udev, udev->actconfig 2250 ? USB_STATE_CONFIGURED 2251 : USB_STATE_ADDRESS); 2252 2253 /* 10.5.4.5 says not to reset a suspended port if the attached 2254 * device is enabled for remote wakeup. Hence the reset 2255 * operation is carried out here, after the port has been 2256 * resumed. 2257 */ 2258 if (udev->reset_resume) 2259 retry_reset_resume: 2260 status = usb_reset_and_verify_device(udev); 2261 2262 /* 10.5.4.5 says be sure devices in the tree are still there. 2263 * For now let's assume the device didn't go crazy on resume, 2264 * and device drivers will know about any resume quirks. 2265 */ 2266 if (status == 0) { 2267 devstatus = 0; 2268 status = usb_get_status(udev, USB_RECIP_DEVICE, 0, &devstatus); 2269 if (status >= 0) 2270 status = (status > 0 ? 0 : -ENODEV); 2271 2272 /* If a normal resume failed, try doing a reset-resume */ 2273 if (status && !udev->reset_resume && udev->persist_enabled) { 2274 dev_dbg(&udev->dev, "retry with reset-resume\n"); 2275 udev->reset_resume = 1; 2276 goto retry_reset_resume; 2277 } 2278 } 2279 2280 if (status) { 2281 dev_dbg(&udev->dev, "gone after usb resume? status %d\n", 2282 status); 2283 } else if (udev->actconfig) { 2284 le16_to_cpus(&devstatus); 2285 if (devstatus & (1 << USB_DEVICE_REMOTE_WAKEUP)) { 2286 status = usb_control_msg(udev, 2287 usb_sndctrlpipe(udev, 0), 2288 USB_REQ_CLEAR_FEATURE, 2289 USB_RECIP_DEVICE, 2290 USB_DEVICE_REMOTE_WAKEUP, 0, 2291 NULL, 0, 2292 USB_CTRL_SET_TIMEOUT); 2293 if (status) 2294 dev_dbg(&udev->dev, 2295 "disable remote wakeup, status %d\n", 2296 status); 2297 } 2298 status = 0; 2299 } 2300 return status; 2301 } 2302 2303 /* 2304 * usb_port_resume - re-activate a suspended usb device's upstream port 2305 * @udev: device to re-activate, not a root hub 2306 * Context: must be able to sleep; device not locked; pm locks held 2307 * 2308 * This will re-activate the suspended device, increasing power usage 2309 * while letting drivers communicate again with its endpoints. 2310 * USB resume explicitly guarantees that the power session between 2311 * the host and the device is the same as it was when the device 2312 * suspended. 2313 * 2314 * If @udev->reset_resume is set then this routine won't check that the 2315 * port is still enabled. Furthermore, finish_port_resume() above will 2316 * reset @udev. The end result is that a broken power session can be 2317 * recovered and @udev will appear to persist across a loss of VBUS power. 2318 * 2319 * For example, if a host controller doesn't maintain VBUS suspend current 2320 * during a system sleep or is reset when the system wakes up, all the USB 2321 * power sessions below it will be broken. This is especially troublesome 2322 * for mass-storage devices containing mounted filesystems, since the 2323 * device will appear to have disconnected and all the memory mappings 2324 * to it will be lost. Using the USB_PERSIST facility, the device can be 2325 * made to appear as if it had not disconnected. 2326 * 2327 * This facility can be dangerous. Although usb_reset_and_verify_device() makes 2328 * every effort to insure that the same device is present after the 2329 * reset as before, it cannot provide a 100% guarantee. Furthermore it's 2330 * quite possible for a device to remain unaltered but its media to be 2331 * changed. If the user replaces a flash memory card while the system is 2332 * asleep, he will have only himself to blame when the filesystem on the 2333 * new card is corrupted and the system crashes. 2334 * 2335 * Returns 0 on success, else negative errno. 2336 */ 2337 int usb_port_resume(struct usb_device *udev, pm_message_t msg) 2338 { 2339 struct usb_hub *hub = hdev_to_hub(udev->parent); 2340 int port1 = udev->portnum; 2341 int status; 2342 u16 portchange, portstatus; 2343 2344 /* Skip the initial Clear-Suspend step for a remote wakeup */ 2345 status = hub_port_status(hub, port1, &portstatus, &portchange); 2346 if (status == 0 && !(portstatus & USB_PORT_STAT_SUSPEND)) 2347 goto SuspendCleared; 2348 2349 // dev_dbg(hub->intfdev, "resume port %d\n", port1); 2350 2351 set_bit(port1, hub->busy_bits); 2352 2353 /* see 7.1.7.7; affects power usage, but not budgeting */ 2354 status = clear_port_feature(hub->hdev, 2355 port1, USB_PORT_FEAT_SUSPEND); 2356 if (status) { 2357 dev_dbg(hub->intfdev, "can't resume port %d, status %d\n", 2358 port1, status); 2359 } else { 2360 /* drive resume for at least 20 msec */ 2361 dev_dbg(&udev->dev, "usb %sresume\n", 2362 (msg.event & PM_EVENT_AUTO ? "auto-" : "")); 2363 msleep(25); 2364 2365 /* Virtual root hubs can trigger on GET_PORT_STATUS to 2366 * stop resume signaling. Then finish the resume 2367 * sequence. 2368 */ 2369 status = hub_port_status(hub, port1, &portstatus, &portchange); 2370 2371 /* TRSMRCY = 10 msec */ 2372 msleep(10); 2373 } 2374 2375 SuspendCleared: 2376 if (status == 0) { 2377 if (portchange & USB_PORT_STAT_C_SUSPEND) 2378 clear_port_feature(hub->hdev, port1, 2379 USB_PORT_FEAT_C_SUSPEND); 2380 } 2381 2382 clear_bit(port1, hub->busy_bits); 2383 2384 status = check_port_resume_type(udev, 2385 hub, port1, status, portchange, portstatus); 2386 if (status == 0) 2387 status = finish_port_resume(udev); 2388 if (status < 0) { 2389 dev_dbg(&udev->dev, "can't resume, status %d\n", status); 2390 hub_port_logical_disconnect(hub, port1); 2391 } 2392 return status; 2393 } 2394 2395 /* caller has locked udev */ 2396 int usb_remote_wakeup(struct usb_device *udev) 2397 { 2398 int status = 0; 2399 2400 if (udev->state == USB_STATE_SUSPENDED) { 2401 dev_dbg(&udev->dev, "usb %sresume\n", "wakeup-"); 2402 status = usb_autoresume_device(udev); 2403 if (status == 0) { 2404 /* Let the drivers do their thing, then... */ 2405 usb_autosuspend_device(udev); 2406 } 2407 } 2408 return status; 2409 } 2410 2411 #else /* CONFIG_USB_SUSPEND */ 2412 2413 /* When CONFIG_USB_SUSPEND isn't set, we never suspend or resume any ports. */ 2414 2415 int usb_port_suspend(struct usb_device *udev, pm_message_t msg) 2416 { 2417 return 0; 2418 } 2419 2420 /* However we may need to do a reset-resume */ 2421 2422 int usb_port_resume(struct usb_device *udev, pm_message_t msg) 2423 { 2424 struct usb_hub *hub = hdev_to_hub(udev->parent); 2425 int port1 = udev->portnum; 2426 int status; 2427 u16 portchange, portstatus; 2428 2429 status = hub_port_status(hub, port1, &portstatus, &portchange); 2430 status = check_port_resume_type(udev, 2431 hub, port1, status, portchange, portstatus); 2432 2433 if (status) { 2434 dev_dbg(&udev->dev, "can't resume, status %d\n", status); 2435 hub_port_logical_disconnect(hub, port1); 2436 } else if (udev->reset_resume) { 2437 dev_dbg(&udev->dev, "reset-resume\n"); 2438 status = usb_reset_and_verify_device(udev); 2439 } 2440 return status; 2441 } 2442 2443 #endif 2444 2445 static int hub_suspend(struct usb_interface *intf, pm_message_t msg) 2446 { 2447 struct usb_hub *hub = usb_get_intfdata (intf); 2448 struct usb_device *hdev = hub->hdev; 2449 unsigned port1; 2450 2451 /* fail if children aren't already suspended */ 2452 for (port1 = 1; port1 <= hdev->maxchild; port1++) { 2453 struct usb_device *udev; 2454 2455 udev = hdev->children [port1-1]; 2456 if (udev && udev->can_submit) { 2457 if (!(msg.event & PM_EVENT_AUTO)) 2458 dev_dbg(&intf->dev, "port %d nyet suspended\n", 2459 port1); 2460 return -EBUSY; 2461 } 2462 } 2463 2464 dev_dbg(&intf->dev, "%s\n", __func__); 2465 2466 /* stop khubd and related activity */ 2467 hub_quiesce(hub, HUB_SUSPEND); 2468 return 0; 2469 } 2470 2471 static int hub_resume(struct usb_interface *intf) 2472 { 2473 struct usb_hub *hub = usb_get_intfdata(intf); 2474 2475 dev_dbg(&intf->dev, "%s\n", __func__); 2476 hub_activate(hub, HUB_RESUME); 2477 return 0; 2478 } 2479 2480 static int hub_reset_resume(struct usb_interface *intf) 2481 { 2482 struct usb_hub *hub = usb_get_intfdata(intf); 2483 2484 dev_dbg(&intf->dev, "%s\n", __func__); 2485 hub_activate(hub, HUB_RESET_RESUME); 2486 return 0; 2487 } 2488 2489 /** 2490 * usb_root_hub_lost_power - called by HCD if the root hub lost Vbus power 2491 * @rhdev: struct usb_device for the root hub 2492 * 2493 * The USB host controller driver calls this function when its root hub 2494 * is resumed and Vbus power has been interrupted or the controller 2495 * has been reset. The routine marks @rhdev as having lost power. 2496 * When the hub driver is resumed it will take notice and carry out 2497 * power-session recovery for all the "USB-PERSIST"-enabled child devices; 2498 * the others will be disconnected. 2499 */ 2500 void usb_root_hub_lost_power(struct usb_device *rhdev) 2501 { 2502 dev_warn(&rhdev->dev, "root hub lost power or was reset\n"); 2503 rhdev->reset_resume = 1; 2504 } 2505 EXPORT_SYMBOL_GPL(usb_root_hub_lost_power); 2506 2507 #else /* CONFIG_PM */ 2508 2509 #define hub_suspend NULL 2510 #define hub_resume NULL 2511 #define hub_reset_resume NULL 2512 #endif 2513 2514 2515 /* USB 2.0 spec, 7.1.7.3 / fig 7-29: 2516 * 2517 * Between connect detection and reset signaling there must be a delay 2518 * of 100ms at least for debounce and power-settling. The corresponding 2519 * timer shall restart whenever the downstream port detects a disconnect. 2520 * 2521 * Apparently there are some bluetooth and irda-dongles and a number of 2522 * low-speed devices for which this debounce period may last over a second. 2523 * Not covered by the spec - but easy to deal with. 2524 * 2525 * This implementation uses a 1500ms total debounce timeout; if the 2526 * connection isn't stable by then it returns -ETIMEDOUT. It checks 2527 * every 25ms for transient disconnects. When the port status has been 2528 * unchanged for 100ms it returns the port status. 2529 */ 2530 static int hub_port_debounce(struct usb_hub *hub, int port1) 2531 { 2532 int ret; 2533 int total_time, stable_time = 0; 2534 u16 portchange, portstatus; 2535 unsigned connection = 0xffff; 2536 2537 for (total_time = 0; ; total_time += HUB_DEBOUNCE_STEP) { 2538 ret = hub_port_status(hub, port1, &portstatus, &portchange); 2539 if (ret < 0) 2540 return ret; 2541 2542 if (!(portchange & USB_PORT_STAT_C_CONNECTION) && 2543 (portstatus & USB_PORT_STAT_CONNECTION) == connection) { 2544 stable_time += HUB_DEBOUNCE_STEP; 2545 if (stable_time >= HUB_DEBOUNCE_STABLE) 2546 break; 2547 } else { 2548 stable_time = 0; 2549 connection = portstatus & USB_PORT_STAT_CONNECTION; 2550 } 2551 2552 if (portchange & USB_PORT_STAT_C_CONNECTION) { 2553 clear_port_feature(hub->hdev, port1, 2554 USB_PORT_FEAT_C_CONNECTION); 2555 } 2556 2557 if (total_time >= HUB_DEBOUNCE_TIMEOUT) 2558 break; 2559 msleep(HUB_DEBOUNCE_STEP); 2560 } 2561 2562 dev_dbg (hub->intfdev, 2563 "debounce: port %d: total %dms stable %dms status 0x%x\n", 2564 port1, total_time, stable_time, portstatus); 2565 2566 if (stable_time < HUB_DEBOUNCE_STABLE) 2567 return -ETIMEDOUT; 2568 return portstatus; 2569 } 2570 2571 void usb_ep0_reinit(struct usb_device *udev) 2572 { 2573 usb_disable_endpoint(udev, 0 + USB_DIR_IN, true); 2574 usb_disable_endpoint(udev, 0 + USB_DIR_OUT, true); 2575 usb_enable_endpoint(udev, &udev->ep0, true); 2576 } 2577 EXPORT_SYMBOL_GPL(usb_ep0_reinit); 2578 2579 #define usb_sndaddr0pipe() (PIPE_CONTROL << 30) 2580 #define usb_rcvaddr0pipe() ((PIPE_CONTROL << 30) | USB_DIR_IN) 2581 2582 static int hub_set_address(struct usb_device *udev, int devnum) 2583 { 2584 int retval; 2585 struct usb_hcd *hcd = bus_to_hcd(udev->bus); 2586 2587 /* 2588 * The host controller will choose the device address, 2589 * instead of the core having chosen it earlier 2590 */ 2591 if (!hcd->driver->address_device && devnum <= 1) 2592 return -EINVAL; 2593 if (udev->state == USB_STATE_ADDRESS) 2594 return 0; 2595 if (udev->state != USB_STATE_DEFAULT) 2596 return -EINVAL; 2597 if (hcd->driver->address_device) { 2598 retval = hcd->driver->address_device(hcd, udev); 2599 } else { 2600 retval = usb_control_msg(udev, usb_sndaddr0pipe(), 2601 USB_REQ_SET_ADDRESS, 0, devnum, 0, 2602 NULL, 0, USB_CTRL_SET_TIMEOUT); 2603 if (retval == 0) 2604 update_address(udev, devnum); 2605 } 2606 if (retval == 0) { 2607 /* Device now using proper address. */ 2608 usb_set_device_state(udev, USB_STATE_ADDRESS); 2609 usb_ep0_reinit(udev); 2610 } 2611 return retval; 2612 } 2613 2614 /* Reset device, (re)assign address, get device descriptor. 2615 * Device connection must be stable, no more debouncing needed. 2616 * Returns device in USB_STATE_ADDRESS, except on error. 2617 * 2618 * If this is called for an already-existing device (as part of 2619 * usb_reset_and_verify_device), the caller must own the device lock. For a 2620 * newly detected device that is not accessible through any global 2621 * pointers, it's not necessary to lock the device. 2622 */ 2623 static int 2624 hub_port_init (struct usb_hub *hub, struct usb_device *udev, int port1, 2625 int retry_counter) 2626 { 2627 static DEFINE_MUTEX(usb_address0_mutex); 2628 2629 struct usb_device *hdev = hub->hdev; 2630 struct usb_hcd *hcd = bus_to_hcd(hdev->bus); 2631 int i, j, retval; 2632 unsigned delay = HUB_SHORT_RESET_TIME; 2633 enum usb_device_speed oldspeed = udev->speed; 2634 char *speed, *type; 2635 int devnum = udev->devnum; 2636 2637 /* root hub ports have a slightly longer reset period 2638 * (from USB 2.0 spec, section 7.1.7.5) 2639 */ 2640 if (!hdev->parent) { 2641 delay = HUB_ROOT_RESET_TIME; 2642 if (port1 == hdev->bus->otg_port) 2643 hdev->bus->b_hnp_enable = 0; 2644 } 2645 2646 /* Some low speed devices have problems with the quick delay, so */ 2647 /* be a bit pessimistic with those devices. RHbug #23670 */ 2648 if (oldspeed == USB_SPEED_LOW) 2649 delay = HUB_LONG_RESET_TIME; 2650 2651 mutex_lock(&usb_address0_mutex); 2652 2653 if (!udev->config && oldspeed == USB_SPEED_SUPER) { 2654 /* Don't reset USB 3.0 devices during an initial setup */ 2655 usb_set_device_state(udev, USB_STATE_DEFAULT); 2656 } else { 2657 /* Reset the device; full speed may morph to high speed */ 2658 /* FIXME a USB 2.0 device may morph into SuperSpeed on reset. */ 2659 retval = hub_port_reset(hub, port1, udev, delay); 2660 if (retval < 0) /* error or disconnect */ 2661 goto fail; 2662 /* success, speed is known */ 2663 } 2664 retval = -ENODEV; 2665 2666 if (oldspeed != USB_SPEED_UNKNOWN && oldspeed != udev->speed) { 2667 dev_dbg(&udev->dev, "device reset changed speed!\n"); 2668 goto fail; 2669 } 2670 oldspeed = udev->speed; 2671 2672 /* USB 2.0 section 5.5.3 talks about ep0 maxpacket ... 2673 * it's fixed size except for full speed devices. 2674 * For Wireless USB devices, ep0 max packet is always 512 (tho 2675 * reported as 0xff in the device descriptor). WUSB1.0[4.8.1]. 2676 */ 2677 switch (udev->speed) { 2678 case USB_SPEED_SUPER: 2679 case USB_SPEED_WIRELESS: /* fixed at 512 */ 2680 udev->ep0.desc.wMaxPacketSize = cpu_to_le16(512); 2681 break; 2682 case USB_SPEED_HIGH: /* fixed at 64 */ 2683 udev->ep0.desc.wMaxPacketSize = cpu_to_le16(64); 2684 break; 2685 case USB_SPEED_FULL: /* 8, 16, 32, or 64 */ 2686 /* to determine the ep0 maxpacket size, try to read 2687 * the device descriptor to get bMaxPacketSize0 and 2688 * then correct our initial guess. 2689 */ 2690 udev->ep0.desc.wMaxPacketSize = cpu_to_le16(64); 2691 break; 2692 case USB_SPEED_LOW: /* fixed at 8 */ 2693 udev->ep0.desc.wMaxPacketSize = cpu_to_le16(8); 2694 break; 2695 default: 2696 goto fail; 2697 } 2698 2699 type = ""; 2700 switch (udev->speed) { 2701 case USB_SPEED_LOW: speed = "low"; break; 2702 case USB_SPEED_FULL: speed = "full"; break; 2703 case USB_SPEED_HIGH: speed = "high"; break; 2704 case USB_SPEED_SUPER: 2705 speed = "super"; 2706 break; 2707 case USB_SPEED_WIRELESS: 2708 speed = "variable"; 2709 type = "Wireless "; 2710 break; 2711 default: speed = "?"; break; 2712 } 2713 if (udev->speed != USB_SPEED_SUPER) 2714 dev_info(&udev->dev, 2715 "%s %s speed %sUSB device using %s and address %d\n", 2716 (udev->config) ? "reset" : "new", speed, type, 2717 udev->bus->controller->driver->name, devnum); 2718 2719 /* Set up TT records, if needed */ 2720 if (hdev->tt) { 2721 udev->tt = hdev->tt; 2722 udev->ttport = hdev->ttport; 2723 } else if (udev->speed != USB_SPEED_HIGH 2724 && hdev->speed == USB_SPEED_HIGH) { 2725 udev->tt = &hub->tt; 2726 udev->ttport = port1; 2727 } 2728 2729 /* Why interleave GET_DESCRIPTOR and SET_ADDRESS this way? 2730 * Because device hardware and firmware is sometimes buggy in 2731 * this area, and this is how Linux has done it for ages. 2732 * Change it cautiously. 2733 * 2734 * NOTE: If USE_NEW_SCHEME() is true we will start by issuing 2735 * a 64-byte GET_DESCRIPTOR request. This is what Windows does, 2736 * so it may help with some non-standards-compliant devices. 2737 * Otherwise we start with SET_ADDRESS and then try to read the 2738 * first 8 bytes of the device descriptor to get the ep0 maxpacket 2739 * value. 2740 */ 2741 for (i = 0; i < GET_DESCRIPTOR_TRIES; (++i, msleep(100))) { 2742 /* 2743 * An xHCI controller cannot send any packets to a device until 2744 * a set address command successfully completes. 2745 */ 2746 if (USE_NEW_SCHEME(retry_counter) && !(hcd->driver->flags & HCD_USB3)) { 2747 struct usb_device_descriptor *buf; 2748 int r = 0; 2749 2750 #define GET_DESCRIPTOR_BUFSIZE 64 2751 buf = kmalloc(GET_DESCRIPTOR_BUFSIZE, GFP_NOIO); 2752 if (!buf) { 2753 retval = -ENOMEM; 2754 continue; 2755 } 2756 2757 /* Retry on all errors; some devices are flakey. 2758 * 255 is for WUSB devices, we actually need to use 2759 * 512 (WUSB1.0[4.8.1]). 2760 */ 2761 for (j = 0; j < 3; ++j) { 2762 buf->bMaxPacketSize0 = 0; 2763 r = usb_control_msg(udev, usb_rcvaddr0pipe(), 2764 USB_REQ_GET_DESCRIPTOR, USB_DIR_IN, 2765 USB_DT_DEVICE << 8, 0, 2766 buf, GET_DESCRIPTOR_BUFSIZE, 2767 initial_descriptor_timeout); 2768 switch (buf->bMaxPacketSize0) { 2769 case 8: case 16: case 32: case 64: case 255: 2770 if (buf->bDescriptorType == 2771 USB_DT_DEVICE) { 2772 r = 0; 2773 break; 2774 } 2775 /* FALL THROUGH */ 2776 default: 2777 if (r == 0) 2778 r = -EPROTO; 2779 break; 2780 } 2781 if (r == 0) 2782 break; 2783 } 2784 udev->descriptor.bMaxPacketSize0 = 2785 buf->bMaxPacketSize0; 2786 kfree(buf); 2787 2788 retval = hub_port_reset(hub, port1, udev, delay); 2789 if (retval < 0) /* error or disconnect */ 2790 goto fail; 2791 if (oldspeed != udev->speed) { 2792 dev_dbg(&udev->dev, 2793 "device reset changed speed!\n"); 2794 retval = -ENODEV; 2795 goto fail; 2796 } 2797 if (r) { 2798 dev_err(&udev->dev, 2799 "device descriptor read/64, error %d\n", 2800 r); 2801 retval = -EMSGSIZE; 2802 continue; 2803 } 2804 #undef GET_DESCRIPTOR_BUFSIZE 2805 } 2806 2807 /* 2808 * If device is WUSB, we already assigned an 2809 * unauthorized address in the Connect Ack sequence; 2810 * authorization will assign the final address. 2811 */ 2812 if (udev->wusb == 0) { 2813 for (j = 0; j < SET_ADDRESS_TRIES; ++j) { 2814 retval = hub_set_address(udev, devnum); 2815 if (retval >= 0) 2816 break; 2817 msleep(200); 2818 } 2819 if (retval < 0) { 2820 dev_err(&udev->dev, 2821 "device not accepting address %d, error %d\n", 2822 devnum, retval); 2823 goto fail; 2824 } 2825 if (udev->speed == USB_SPEED_SUPER) { 2826 devnum = udev->devnum; 2827 dev_info(&udev->dev, 2828 "%s SuperSpeed USB device using %s and address %d\n", 2829 (udev->config) ? "reset" : "new", 2830 udev->bus->controller->driver->name, devnum); 2831 } 2832 2833 /* cope with hardware quirkiness: 2834 * - let SET_ADDRESS settle, some device hardware wants it 2835 * - read ep0 maxpacket even for high and low speed, 2836 */ 2837 msleep(10); 2838 if (USE_NEW_SCHEME(retry_counter) && !(hcd->driver->flags & HCD_USB3)) 2839 break; 2840 } 2841 2842 retval = usb_get_device_descriptor(udev, 8); 2843 if (retval < 8) { 2844 dev_err(&udev->dev, 2845 "device descriptor read/8, error %d\n", 2846 retval); 2847 if (retval >= 0) 2848 retval = -EMSGSIZE; 2849 } else { 2850 retval = 0; 2851 break; 2852 } 2853 } 2854 if (retval) 2855 goto fail; 2856 2857 if (udev->descriptor.bMaxPacketSize0 == 0xff || 2858 udev->speed == USB_SPEED_SUPER) 2859 i = 512; 2860 else 2861 i = udev->descriptor.bMaxPacketSize0; 2862 if (le16_to_cpu(udev->ep0.desc.wMaxPacketSize) != i) { 2863 if (udev->speed != USB_SPEED_FULL || 2864 !(i == 8 || i == 16 || i == 32 || i == 64)) { 2865 dev_err(&udev->dev, "ep0 maxpacket = %d\n", i); 2866 retval = -EMSGSIZE; 2867 goto fail; 2868 } 2869 dev_dbg(&udev->dev, "ep0 maxpacket = %d\n", i); 2870 udev->ep0.desc.wMaxPacketSize = cpu_to_le16(i); 2871 usb_ep0_reinit(udev); 2872 } 2873 2874 retval = usb_get_device_descriptor(udev, USB_DT_DEVICE_SIZE); 2875 if (retval < (signed)sizeof(udev->descriptor)) { 2876 dev_err(&udev->dev, "device descriptor read/all, error %d\n", 2877 retval); 2878 if (retval >= 0) 2879 retval = -ENOMSG; 2880 goto fail; 2881 } 2882 2883 retval = 0; 2884 /* notify HCD that we have a device connected and addressed */ 2885 if (hcd->driver->update_device) 2886 hcd->driver->update_device(hcd, udev); 2887 fail: 2888 if (retval) { 2889 hub_port_disable(hub, port1, 0); 2890 update_address(udev, devnum); /* for disconnect processing */ 2891 } 2892 mutex_unlock(&usb_address0_mutex); 2893 return retval; 2894 } 2895 2896 static void 2897 check_highspeed (struct usb_hub *hub, struct usb_device *udev, int port1) 2898 { 2899 struct usb_qualifier_descriptor *qual; 2900 int status; 2901 2902 qual = kmalloc (sizeof *qual, GFP_KERNEL); 2903 if (qual == NULL) 2904 return; 2905 2906 status = usb_get_descriptor (udev, USB_DT_DEVICE_QUALIFIER, 0, 2907 qual, sizeof *qual); 2908 if (status == sizeof *qual) { 2909 dev_info(&udev->dev, "not running at top speed; " 2910 "connect to a high speed hub\n"); 2911 /* hub LEDs are probably harder to miss than syslog */ 2912 if (hub->has_indicators) { 2913 hub->indicator[port1-1] = INDICATOR_GREEN_BLINK; 2914 schedule_delayed_work (&hub->leds, 0); 2915 } 2916 } 2917 kfree(qual); 2918 } 2919 2920 static unsigned 2921 hub_power_remaining (struct usb_hub *hub) 2922 { 2923 struct usb_device *hdev = hub->hdev; 2924 int remaining; 2925 int port1; 2926 2927 if (!hub->limited_power) 2928 return 0; 2929 2930 remaining = hdev->bus_mA - hub->descriptor->bHubContrCurrent; 2931 for (port1 = 1; port1 <= hdev->maxchild; ++port1) { 2932 struct usb_device *udev = hdev->children[port1 - 1]; 2933 int delta; 2934 2935 if (!udev) 2936 continue; 2937 2938 /* Unconfigured devices may not use more than 100mA, 2939 * or 8mA for OTG ports */ 2940 if (udev->actconfig) 2941 delta = udev->actconfig->desc.bMaxPower * 2; 2942 else if (port1 != udev->bus->otg_port || hdev->parent) 2943 delta = 100; 2944 else 2945 delta = 8; 2946 if (delta > hub->mA_per_port) 2947 dev_warn(&udev->dev, 2948 "%dmA is over %umA budget for port %d!\n", 2949 delta, hub->mA_per_port, port1); 2950 remaining -= delta; 2951 } 2952 if (remaining < 0) { 2953 dev_warn(hub->intfdev, "%dmA over power budget!\n", 2954 - remaining); 2955 remaining = 0; 2956 } 2957 return remaining; 2958 } 2959 2960 /* Handle physical or logical connection change events. 2961 * This routine is called when: 2962 * a port connection-change occurs; 2963 * a port enable-change occurs (often caused by EMI); 2964 * usb_reset_and_verify_device() encounters changed descriptors (as from 2965 * a firmware download) 2966 * caller already locked the hub 2967 */ 2968 static void hub_port_connect_change(struct usb_hub *hub, int port1, 2969 u16 portstatus, u16 portchange) 2970 { 2971 struct usb_device *hdev = hub->hdev; 2972 struct device *hub_dev = hub->intfdev; 2973 struct usb_hcd *hcd = bus_to_hcd(hdev->bus); 2974 unsigned wHubCharacteristics = 2975 le16_to_cpu(hub->descriptor->wHubCharacteristics); 2976 struct usb_device *udev; 2977 int status, i; 2978 2979 dev_dbg (hub_dev, 2980 "port %d, status %04x, change %04x, %s\n", 2981 port1, portstatus, portchange, portspeed (portstatus)); 2982 2983 if (hub->has_indicators) { 2984 set_port_led(hub, port1, HUB_LED_AUTO); 2985 hub->indicator[port1-1] = INDICATOR_AUTO; 2986 } 2987 2988 #ifdef CONFIG_USB_OTG 2989 /* during HNP, don't repeat the debounce */ 2990 if (hdev->bus->is_b_host) 2991 portchange &= ~(USB_PORT_STAT_C_CONNECTION | 2992 USB_PORT_STAT_C_ENABLE); 2993 #endif 2994 2995 /* Try to resuscitate an existing device */ 2996 udev = hdev->children[port1-1]; 2997 if ((portstatus & USB_PORT_STAT_CONNECTION) && udev && 2998 udev->state != USB_STATE_NOTATTACHED) { 2999 usb_lock_device(udev); 3000 if (portstatus & USB_PORT_STAT_ENABLE) { 3001 status = 0; /* Nothing to do */ 3002 3003 #ifdef CONFIG_USB_SUSPEND 3004 } else if (udev->state == USB_STATE_SUSPENDED && 3005 udev->persist_enabled) { 3006 /* For a suspended device, treat this as a 3007 * remote wakeup event. 3008 */ 3009 status = usb_remote_wakeup(udev); 3010 #endif 3011 3012 } else { 3013 status = -ENODEV; /* Don't resuscitate */ 3014 } 3015 usb_unlock_device(udev); 3016 3017 if (status == 0) { 3018 clear_bit(port1, hub->change_bits); 3019 return; 3020 } 3021 } 3022 3023 /* Disconnect any existing devices under this port */ 3024 if (udev) 3025 usb_disconnect(&hdev->children[port1-1]); 3026 clear_bit(port1, hub->change_bits); 3027 3028 /* We can forget about a "removed" device when there's a physical 3029 * disconnect or the connect status changes. 3030 */ 3031 if (!(portstatus & USB_PORT_STAT_CONNECTION) || 3032 (portchange & USB_PORT_STAT_C_CONNECTION)) 3033 clear_bit(port1, hub->removed_bits); 3034 3035 if (portchange & (USB_PORT_STAT_C_CONNECTION | 3036 USB_PORT_STAT_C_ENABLE)) { 3037 status = hub_port_debounce(hub, port1); 3038 if (status < 0) { 3039 if (printk_ratelimit()) 3040 dev_err(hub_dev, "connect-debounce failed, " 3041 "port %d disabled\n", port1); 3042 portstatus &= ~USB_PORT_STAT_CONNECTION; 3043 } else { 3044 portstatus = status; 3045 } 3046 } 3047 3048 /* Return now if debouncing failed or nothing is connected or 3049 * the device was "removed". 3050 */ 3051 if (!(portstatus & USB_PORT_STAT_CONNECTION) || 3052 test_bit(port1, hub->removed_bits)) { 3053 3054 /* maybe switch power back on (e.g. root hub was reset) */ 3055 if ((wHubCharacteristics & HUB_CHAR_LPSM) < 2 3056 && !(portstatus & USB_PORT_STAT_POWER)) 3057 set_port_feature(hdev, port1, USB_PORT_FEAT_POWER); 3058 3059 if (portstatus & USB_PORT_STAT_ENABLE) 3060 goto done; 3061 return; 3062 } 3063 3064 for (i = 0; i < SET_CONFIG_TRIES; i++) { 3065 3066 /* reallocate for each attempt, since references 3067 * to the previous one can escape in various ways 3068 */ 3069 udev = usb_alloc_dev(hdev, hdev->bus, port1); 3070 if (!udev) { 3071 dev_err (hub_dev, 3072 "couldn't allocate port %d usb_device\n", 3073 port1); 3074 goto done; 3075 } 3076 3077 usb_set_device_state(udev, USB_STATE_POWERED); 3078 udev->bus_mA = hub->mA_per_port; 3079 udev->level = hdev->level + 1; 3080 udev->wusb = hub_is_wusb(hub); 3081 3082 /* 3083 * USB 3.0 devices are reset automatically before the connect 3084 * port status change appears, and the root hub port status 3085 * shows the correct speed. We also get port change 3086 * notifications for USB 3.0 devices from the USB 3.0 portion of 3087 * an external USB 3.0 hub, but this isn't handled correctly yet 3088 * FIXME. 3089 */ 3090 3091 if (!(hcd->driver->flags & HCD_USB3)) 3092 udev->speed = USB_SPEED_UNKNOWN; 3093 else if ((hdev->parent == NULL) && 3094 (portstatus & USB_PORT_STAT_SUPER_SPEED)) 3095 udev->speed = USB_SPEED_SUPER; 3096 else 3097 udev->speed = USB_SPEED_UNKNOWN; 3098 3099 /* 3100 * xHCI needs to issue an address device command later 3101 * in the hub_port_init sequence for SS/HS/FS/LS devices. 3102 */ 3103 if (!(hcd->driver->flags & HCD_USB3)) { 3104 /* set the address */ 3105 choose_address(udev); 3106 if (udev->devnum <= 0) { 3107 status = -ENOTCONN; /* Don't retry */ 3108 goto loop; 3109 } 3110 } 3111 3112 /* reset (non-USB 3.0 devices) and get descriptor */ 3113 status = hub_port_init(hub, udev, port1, i); 3114 if (status < 0) 3115 goto loop; 3116 3117 usb_detect_quirks(udev); 3118 if (udev->quirks & USB_QUIRK_DELAY_INIT) 3119 msleep(1000); 3120 3121 /* consecutive bus-powered hubs aren't reliable; they can 3122 * violate the voltage drop budget. if the new child has 3123 * a "powered" LED, users should notice we didn't enable it 3124 * (without reading syslog), even without per-port LEDs 3125 * on the parent. 3126 */ 3127 if (udev->descriptor.bDeviceClass == USB_CLASS_HUB 3128 && udev->bus_mA <= 100) { 3129 u16 devstat; 3130 3131 status = usb_get_status(udev, USB_RECIP_DEVICE, 0, 3132 &devstat); 3133 if (status < 2) { 3134 dev_dbg(&udev->dev, "get status %d ?\n", status); 3135 goto loop_disable; 3136 } 3137 le16_to_cpus(&devstat); 3138 if ((devstat & (1 << USB_DEVICE_SELF_POWERED)) == 0) { 3139 dev_err(&udev->dev, 3140 "can't connect bus-powered hub " 3141 "to this port\n"); 3142 if (hub->has_indicators) { 3143 hub->indicator[port1-1] = 3144 INDICATOR_AMBER_BLINK; 3145 schedule_delayed_work (&hub->leds, 0); 3146 } 3147 status = -ENOTCONN; /* Don't retry */ 3148 goto loop_disable; 3149 } 3150 } 3151 3152 /* check for devices running slower than they could */ 3153 if (le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0200 3154 && udev->speed == USB_SPEED_FULL 3155 && highspeed_hubs != 0) 3156 check_highspeed (hub, udev, port1); 3157 3158 /* Store the parent's children[] pointer. At this point 3159 * udev becomes globally accessible, although presumably 3160 * no one will look at it until hdev is unlocked. 3161 */ 3162 status = 0; 3163 3164 /* We mustn't add new devices if the parent hub has 3165 * been disconnected; we would race with the 3166 * recursively_mark_NOTATTACHED() routine. 3167 */ 3168 spin_lock_irq(&device_state_lock); 3169 if (hdev->state == USB_STATE_NOTATTACHED) 3170 status = -ENOTCONN; 3171 else 3172 hdev->children[port1-1] = udev; 3173 spin_unlock_irq(&device_state_lock); 3174 3175 /* Run it through the hoops (find a driver, etc) */ 3176 if (!status) { 3177 status = usb_new_device(udev); 3178 if (status) { 3179 spin_lock_irq(&device_state_lock); 3180 hdev->children[port1-1] = NULL; 3181 spin_unlock_irq(&device_state_lock); 3182 } 3183 } 3184 3185 if (status) 3186 goto loop_disable; 3187 3188 status = hub_power_remaining(hub); 3189 if (status) 3190 dev_dbg(hub_dev, "%dmA power budget left\n", status); 3191 3192 return; 3193 3194 loop_disable: 3195 hub_port_disable(hub, port1, 1); 3196 loop: 3197 usb_ep0_reinit(udev); 3198 release_address(udev); 3199 hub_free_dev(udev); 3200 usb_put_dev(udev); 3201 if ((status == -ENOTCONN) || (status == -ENOTSUPP)) 3202 break; 3203 } 3204 if (hub->hdev->parent || 3205 !hcd->driver->port_handed_over || 3206 !(hcd->driver->port_handed_over)(hcd, port1)) 3207 dev_err(hub_dev, "unable to enumerate USB device on port %d\n", 3208 port1); 3209 3210 done: 3211 hub_port_disable(hub, port1, 1); 3212 if (hcd->driver->relinquish_port && !hub->hdev->parent) 3213 hcd->driver->relinquish_port(hcd, port1); 3214 } 3215 3216 static void hub_events(void) 3217 { 3218 struct list_head *tmp; 3219 struct usb_device *hdev; 3220 struct usb_interface *intf; 3221 struct usb_hub *hub; 3222 struct device *hub_dev; 3223 u16 hubstatus; 3224 u16 hubchange; 3225 u16 portstatus; 3226 u16 portchange; 3227 int i, ret; 3228 int connect_change; 3229 3230 /* 3231 * We restart the list every time to avoid a deadlock with 3232 * deleting hubs downstream from this one. This should be 3233 * safe since we delete the hub from the event list. 3234 * Not the most efficient, but avoids deadlocks. 3235 */ 3236 while (1) { 3237 3238 /* Grab the first entry at the beginning of the list */ 3239 spin_lock_irq(&hub_event_lock); 3240 if (list_empty(&hub_event_list)) { 3241 spin_unlock_irq(&hub_event_lock); 3242 break; 3243 } 3244 3245 tmp = hub_event_list.next; 3246 list_del_init(tmp); 3247 3248 hub = list_entry(tmp, struct usb_hub, event_list); 3249 kref_get(&hub->kref); 3250 spin_unlock_irq(&hub_event_lock); 3251 3252 hdev = hub->hdev; 3253 hub_dev = hub->intfdev; 3254 intf = to_usb_interface(hub_dev); 3255 dev_dbg(hub_dev, "state %d ports %d chg %04x evt %04x\n", 3256 hdev->state, hub->descriptor 3257 ? hub->descriptor->bNbrPorts 3258 : 0, 3259 /* NOTE: expects max 15 ports... */ 3260 (u16) hub->change_bits[0], 3261 (u16) hub->event_bits[0]); 3262 3263 /* Lock the device, then check to see if we were 3264 * disconnected while waiting for the lock to succeed. */ 3265 usb_lock_device(hdev); 3266 if (unlikely(hub->disconnected)) 3267 goto loop_disconnected; 3268 3269 /* If the hub has died, clean up after it */ 3270 if (hdev->state == USB_STATE_NOTATTACHED) { 3271 hub->error = -ENODEV; 3272 hub_quiesce(hub, HUB_DISCONNECT); 3273 goto loop; 3274 } 3275 3276 /* Autoresume */ 3277 ret = usb_autopm_get_interface(intf); 3278 if (ret) { 3279 dev_dbg(hub_dev, "Can't autoresume: %d\n", ret); 3280 goto loop; 3281 } 3282 3283 /* If this is an inactive hub, do nothing */ 3284 if (hub->quiescing) 3285 goto loop_autopm; 3286 3287 if (hub->error) { 3288 dev_dbg (hub_dev, "resetting for error %d\n", 3289 hub->error); 3290 3291 ret = usb_reset_device(hdev); 3292 if (ret) { 3293 dev_dbg (hub_dev, 3294 "error resetting hub: %d\n", ret); 3295 goto loop_autopm; 3296 } 3297 3298 hub->nerrors = 0; 3299 hub->error = 0; 3300 } 3301 3302 /* deal with port status changes */ 3303 for (i = 1; i <= hub->descriptor->bNbrPorts; i++) { 3304 if (test_bit(i, hub->busy_bits)) 3305 continue; 3306 connect_change = test_bit(i, hub->change_bits); 3307 if (!test_and_clear_bit(i, hub->event_bits) && 3308 !connect_change) 3309 continue; 3310 3311 ret = hub_port_status(hub, i, 3312 &portstatus, &portchange); 3313 if (ret < 0) 3314 continue; 3315 3316 if (portchange & USB_PORT_STAT_C_CONNECTION) { 3317 clear_port_feature(hdev, i, 3318 USB_PORT_FEAT_C_CONNECTION); 3319 connect_change = 1; 3320 } 3321 3322 if (portchange & USB_PORT_STAT_C_ENABLE) { 3323 if (!connect_change) 3324 dev_dbg (hub_dev, 3325 "port %d enable change, " 3326 "status %08x\n", 3327 i, portstatus); 3328 clear_port_feature(hdev, i, 3329 USB_PORT_FEAT_C_ENABLE); 3330 3331 /* 3332 * EM interference sometimes causes badly 3333 * shielded USB devices to be shutdown by 3334 * the hub, this hack enables them again. 3335 * Works at least with mouse driver. 3336 */ 3337 if (!(portstatus & USB_PORT_STAT_ENABLE) 3338 && !connect_change 3339 && hdev->children[i-1]) { 3340 dev_err (hub_dev, 3341 "port %i " 3342 "disabled by hub (EMI?), " 3343 "re-enabling...\n", 3344 i); 3345 connect_change = 1; 3346 } 3347 } 3348 3349 if (portchange & USB_PORT_STAT_C_SUSPEND) { 3350 struct usb_device *udev; 3351 3352 clear_port_feature(hdev, i, 3353 USB_PORT_FEAT_C_SUSPEND); 3354 udev = hdev->children[i-1]; 3355 if (udev) { 3356 /* TRSMRCY = 10 msec */ 3357 msleep(10); 3358 3359 usb_lock_device(udev); 3360 ret = usb_remote_wakeup(hdev-> 3361 children[i-1]); 3362 usb_unlock_device(udev); 3363 if (ret < 0) 3364 connect_change = 1; 3365 } else { 3366 ret = -ENODEV; 3367 hub_port_disable(hub, i, 1); 3368 } 3369 dev_dbg (hub_dev, 3370 "resume on port %d, status %d\n", 3371 i, ret); 3372 } 3373 3374 if (portchange & USB_PORT_STAT_C_OVERCURRENT) { 3375 dev_err (hub_dev, 3376 "over-current change on port %d\n", 3377 i); 3378 clear_port_feature(hdev, i, 3379 USB_PORT_FEAT_C_OVER_CURRENT); 3380 hub_power_on(hub, true); 3381 } 3382 3383 if (portchange & USB_PORT_STAT_C_RESET) { 3384 dev_dbg (hub_dev, 3385 "reset change on port %d\n", 3386 i); 3387 clear_port_feature(hdev, i, 3388 USB_PORT_FEAT_C_RESET); 3389 } 3390 3391 if (connect_change) 3392 hub_port_connect_change(hub, i, 3393 portstatus, portchange); 3394 } /* end for i */ 3395 3396 /* deal with hub status changes */ 3397 if (test_and_clear_bit(0, hub->event_bits) == 0) 3398 ; /* do nothing */ 3399 else if (hub_hub_status(hub, &hubstatus, &hubchange) < 0) 3400 dev_err (hub_dev, "get_hub_status failed\n"); 3401 else { 3402 if (hubchange & HUB_CHANGE_LOCAL_POWER) { 3403 dev_dbg (hub_dev, "power change\n"); 3404 clear_hub_feature(hdev, C_HUB_LOCAL_POWER); 3405 if (hubstatus & HUB_STATUS_LOCAL_POWER) 3406 /* FIXME: Is this always true? */ 3407 hub->limited_power = 1; 3408 else 3409 hub->limited_power = 0; 3410 } 3411 if (hubchange & HUB_CHANGE_OVERCURRENT) { 3412 dev_dbg (hub_dev, "overcurrent change\n"); 3413 msleep(500); /* Cool down */ 3414 clear_hub_feature(hdev, C_HUB_OVER_CURRENT); 3415 hub_power_on(hub, true); 3416 } 3417 } 3418 3419 loop_autopm: 3420 /* Balance the usb_autopm_get_interface() above */ 3421 usb_autopm_put_interface_no_suspend(intf); 3422 loop: 3423 /* Balance the usb_autopm_get_interface_no_resume() in 3424 * kick_khubd() and allow autosuspend. 3425 */ 3426 usb_autopm_put_interface(intf); 3427 loop_disconnected: 3428 usb_unlock_device(hdev); 3429 kref_put(&hub->kref, hub_release); 3430 3431 } /* end while (1) */ 3432 } 3433 3434 static int hub_thread(void *__unused) 3435 { 3436 /* khubd needs to be freezable to avoid intefering with USB-PERSIST 3437 * port handover. Otherwise it might see that a full-speed device 3438 * was gone before the EHCI controller had handed its port over to 3439 * the companion full-speed controller. 3440 */ 3441 set_freezable(); 3442 3443 do { 3444 hub_events(); 3445 wait_event_freezable(khubd_wait, 3446 !list_empty(&hub_event_list) || 3447 kthread_should_stop()); 3448 } while (!kthread_should_stop() || !list_empty(&hub_event_list)); 3449 3450 pr_debug("%s: khubd exiting\n", usbcore_name); 3451 return 0; 3452 } 3453 3454 static const struct usb_device_id hub_id_table[] = { 3455 { .match_flags = USB_DEVICE_ID_MATCH_DEV_CLASS, 3456 .bDeviceClass = USB_CLASS_HUB}, 3457 { .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS, 3458 .bInterfaceClass = USB_CLASS_HUB}, 3459 { } /* Terminating entry */ 3460 }; 3461 3462 MODULE_DEVICE_TABLE (usb, hub_id_table); 3463 3464 static struct usb_driver hub_driver = { 3465 .name = "hub", 3466 .probe = hub_probe, 3467 .disconnect = hub_disconnect, 3468 .suspend = hub_suspend, 3469 .resume = hub_resume, 3470 .reset_resume = hub_reset_resume, 3471 .pre_reset = hub_pre_reset, 3472 .post_reset = hub_post_reset, 3473 .unlocked_ioctl = hub_ioctl, 3474 .id_table = hub_id_table, 3475 .supports_autosuspend = 1, 3476 }; 3477 3478 int usb_hub_init(void) 3479 { 3480 if (usb_register(&hub_driver) < 0) { 3481 printk(KERN_ERR "%s: can't register hub driver\n", 3482 usbcore_name); 3483 return -1; 3484 } 3485 3486 khubd_task = kthread_run(hub_thread, NULL, "khubd"); 3487 if (!IS_ERR(khubd_task)) 3488 return 0; 3489 3490 /* Fall through if kernel_thread failed */ 3491 usb_deregister(&hub_driver); 3492 printk(KERN_ERR "%s: can't start khubd\n", usbcore_name); 3493 3494 return -1; 3495 } 3496 3497 void usb_hub_cleanup(void) 3498 { 3499 kthread_stop(khubd_task); 3500 3501 /* 3502 * Hub resources are freed for us by usb_deregister. It calls 3503 * usb_driver_purge on every device which in turn calls that 3504 * devices disconnect function if it is using this driver. 3505 * The hub_disconnect function takes care of releasing the 3506 * individual hub resources. -greg 3507 */ 3508 usb_deregister(&hub_driver); 3509 } /* usb_hub_cleanup() */ 3510 3511 static int descriptors_changed(struct usb_device *udev, 3512 struct usb_device_descriptor *old_device_descriptor) 3513 { 3514 int changed = 0; 3515 unsigned index; 3516 unsigned serial_len = 0; 3517 unsigned len; 3518 unsigned old_length; 3519 int length; 3520 char *buf; 3521 3522 if (memcmp(&udev->descriptor, old_device_descriptor, 3523 sizeof(*old_device_descriptor)) != 0) 3524 return 1; 3525 3526 /* Since the idVendor, idProduct, and bcdDevice values in the 3527 * device descriptor haven't changed, we will assume the 3528 * Manufacturer and Product strings haven't changed either. 3529 * But the SerialNumber string could be different (e.g., a 3530 * different flash card of the same brand). 3531 */ 3532 if (udev->serial) 3533 serial_len = strlen(udev->serial) + 1; 3534 3535 len = serial_len; 3536 for (index = 0; index < udev->descriptor.bNumConfigurations; index++) { 3537 old_length = le16_to_cpu(udev->config[index].desc.wTotalLength); 3538 len = max(len, old_length); 3539 } 3540 3541 buf = kmalloc(len, GFP_NOIO); 3542 if (buf == NULL) { 3543 dev_err(&udev->dev, "no mem to re-read configs after reset\n"); 3544 /* assume the worst */ 3545 return 1; 3546 } 3547 for (index = 0; index < udev->descriptor.bNumConfigurations; index++) { 3548 old_length = le16_to_cpu(udev->config[index].desc.wTotalLength); 3549 length = usb_get_descriptor(udev, USB_DT_CONFIG, index, buf, 3550 old_length); 3551 if (length != old_length) { 3552 dev_dbg(&udev->dev, "config index %d, error %d\n", 3553 index, length); 3554 changed = 1; 3555 break; 3556 } 3557 if (memcmp (buf, udev->rawdescriptors[index], old_length) 3558 != 0) { 3559 dev_dbg(&udev->dev, "config index %d changed (#%d)\n", 3560 index, 3561 ((struct usb_config_descriptor *) buf)-> 3562 bConfigurationValue); 3563 changed = 1; 3564 break; 3565 } 3566 } 3567 3568 if (!changed && serial_len) { 3569 length = usb_string(udev, udev->descriptor.iSerialNumber, 3570 buf, serial_len); 3571 if (length + 1 != serial_len) { 3572 dev_dbg(&udev->dev, "serial string error %d\n", 3573 length); 3574 changed = 1; 3575 } else if (memcmp(buf, udev->serial, length) != 0) { 3576 dev_dbg(&udev->dev, "serial string changed\n"); 3577 changed = 1; 3578 } 3579 } 3580 3581 kfree(buf); 3582 return changed; 3583 } 3584 3585 /** 3586 * usb_reset_and_verify_device - perform a USB port reset to reinitialize a device 3587 * @udev: device to reset (not in SUSPENDED or NOTATTACHED state) 3588 * 3589 * WARNING - don't use this routine to reset a composite device 3590 * (one with multiple interfaces owned by separate drivers)! 3591 * Use usb_reset_device() instead. 3592 * 3593 * Do a port reset, reassign the device's address, and establish its 3594 * former operating configuration. If the reset fails, or the device's 3595 * descriptors change from their values before the reset, or the original 3596 * configuration and altsettings cannot be restored, a flag will be set 3597 * telling khubd to pretend the device has been disconnected and then 3598 * re-connected. All drivers will be unbound, and the device will be 3599 * re-enumerated and probed all over again. 3600 * 3601 * Returns 0 if the reset succeeded, -ENODEV if the device has been 3602 * flagged for logical disconnection, or some other negative error code 3603 * if the reset wasn't even attempted. 3604 * 3605 * The caller must own the device lock. For example, it's safe to use 3606 * this from a driver probe() routine after downloading new firmware. 3607 * For calls that might not occur during probe(), drivers should lock 3608 * the device using usb_lock_device_for_reset(). 3609 * 3610 * Locking exception: This routine may also be called from within an 3611 * autoresume handler. Such usage won't conflict with other tasks 3612 * holding the device lock because these tasks should always call 3613 * usb_autopm_resume_device(), thereby preventing any unwanted autoresume. 3614 */ 3615 static int usb_reset_and_verify_device(struct usb_device *udev) 3616 { 3617 struct usb_device *parent_hdev = udev->parent; 3618 struct usb_hub *parent_hub; 3619 struct usb_hcd *hcd = bus_to_hcd(udev->bus); 3620 struct usb_device_descriptor descriptor = udev->descriptor; 3621 int i, ret = 0; 3622 int port1 = udev->portnum; 3623 3624 if (udev->state == USB_STATE_NOTATTACHED || 3625 udev->state == USB_STATE_SUSPENDED) { 3626 dev_dbg(&udev->dev, "device reset not allowed in state %d\n", 3627 udev->state); 3628 return -EINVAL; 3629 } 3630 3631 if (!parent_hdev) { 3632 /* this requires hcd-specific logic; see OHCI hc_restart() */ 3633 dev_dbg(&udev->dev, "%s for root hub!\n", __func__); 3634 return -EISDIR; 3635 } 3636 parent_hub = hdev_to_hub(parent_hdev); 3637 3638 set_bit(port1, parent_hub->busy_bits); 3639 for (i = 0; i < SET_CONFIG_TRIES; ++i) { 3640 3641 /* ep0 maxpacket size may change; let the HCD know about it. 3642 * Other endpoints will be handled by re-enumeration. */ 3643 usb_ep0_reinit(udev); 3644 ret = hub_port_init(parent_hub, udev, port1, i); 3645 if (ret >= 0 || ret == -ENOTCONN || ret == -ENODEV) 3646 break; 3647 } 3648 clear_bit(port1, parent_hub->busy_bits); 3649 3650 if (ret < 0) 3651 goto re_enumerate; 3652 3653 /* Device might have changed firmware (DFU or similar) */ 3654 if (descriptors_changed(udev, &descriptor)) { 3655 dev_info(&udev->dev, "device firmware changed\n"); 3656 udev->descriptor = descriptor; /* for disconnect() calls */ 3657 goto re_enumerate; 3658 } 3659 3660 /* Restore the device's previous configuration */ 3661 if (!udev->actconfig) 3662 goto done; 3663 3664 mutex_lock(&hcd->bandwidth_mutex); 3665 ret = usb_hcd_alloc_bandwidth(udev, udev->actconfig, NULL, NULL); 3666 if (ret < 0) { 3667 dev_warn(&udev->dev, 3668 "Busted HC? Not enough HCD resources for " 3669 "old configuration.\n"); 3670 mutex_unlock(&hcd->bandwidth_mutex); 3671 goto re_enumerate; 3672 } 3673 ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0), 3674 USB_REQ_SET_CONFIGURATION, 0, 3675 udev->actconfig->desc.bConfigurationValue, 0, 3676 NULL, 0, USB_CTRL_SET_TIMEOUT); 3677 if (ret < 0) { 3678 dev_err(&udev->dev, 3679 "can't restore configuration #%d (error=%d)\n", 3680 udev->actconfig->desc.bConfigurationValue, ret); 3681 mutex_unlock(&hcd->bandwidth_mutex); 3682 goto re_enumerate; 3683 } 3684 mutex_unlock(&hcd->bandwidth_mutex); 3685 usb_set_device_state(udev, USB_STATE_CONFIGURED); 3686 3687 /* Put interfaces back into the same altsettings as before. 3688 * Don't bother to send the Set-Interface request for interfaces 3689 * that were already in altsetting 0; besides being unnecessary, 3690 * many devices can't handle it. Instead just reset the host-side 3691 * endpoint state. 3692 */ 3693 for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) { 3694 struct usb_host_config *config = udev->actconfig; 3695 struct usb_interface *intf = config->interface[i]; 3696 struct usb_interface_descriptor *desc; 3697 3698 desc = &intf->cur_altsetting->desc; 3699 if (desc->bAlternateSetting == 0) { 3700 usb_disable_interface(udev, intf, true); 3701 usb_enable_interface(udev, intf, true); 3702 ret = 0; 3703 } else { 3704 /* Let the bandwidth allocation function know that this 3705 * device has been reset, and it will have to use 3706 * alternate setting 0 as the current alternate setting. 3707 */ 3708 intf->resetting_device = 1; 3709 ret = usb_set_interface(udev, desc->bInterfaceNumber, 3710 desc->bAlternateSetting); 3711 intf->resetting_device = 0; 3712 } 3713 if (ret < 0) { 3714 dev_err(&udev->dev, "failed to restore interface %d " 3715 "altsetting %d (error=%d)\n", 3716 desc->bInterfaceNumber, 3717 desc->bAlternateSetting, 3718 ret); 3719 goto re_enumerate; 3720 } 3721 } 3722 3723 done: 3724 return 0; 3725 3726 re_enumerate: 3727 hub_port_logical_disconnect(parent_hub, port1); 3728 return -ENODEV; 3729 } 3730 3731 /** 3732 * usb_reset_device - warn interface drivers and perform a USB port reset 3733 * @udev: device to reset (not in SUSPENDED or NOTATTACHED state) 3734 * 3735 * Warns all drivers bound to registered interfaces (using their pre_reset 3736 * method), performs the port reset, and then lets the drivers know that 3737 * the reset is over (using their post_reset method). 3738 * 3739 * Return value is the same as for usb_reset_and_verify_device(). 3740 * 3741 * The caller must own the device lock. For example, it's safe to use 3742 * this from a driver probe() routine after downloading new firmware. 3743 * For calls that might not occur during probe(), drivers should lock 3744 * the device using usb_lock_device_for_reset(). 3745 * 3746 * If an interface is currently being probed or disconnected, we assume 3747 * its driver knows how to handle resets. For all other interfaces, 3748 * if the driver doesn't have pre_reset and post_reset methods then 3749 * we attempt to unbind it and rebind afterward. 3750 */ 3751 int usb_reset_device(struct usb_device *udev) 3752 { 3753 int ret; 3754 int i; 3755 struct usb_host_config *config = udev->actconfig; 3756 3757 if (udev->state == USB_STATE_NOTATTACHED || 3758 udev->state == USB_STATE_SUSPENDED) { 3759 dev_dbg(&udev->dev, "device reset not allowed in state %d\n", 3760 udev->state); 3761 return -EINVAL; 3762 } 3763 3764 /* Prevent autosuspend during the reset */ 3765 usb_autoresume_device(udev); 3766 3767 if (config) { 3768 for (i = 0; i < config->desc.bNumInterfaces; ++i) { 3769 struct usb_interface *cintf = config->interface[i]; 3770 struct usb_driver *drv; 3771 int unbind = 0; 3772 3773 if (cintf->dev.driver) { 3774 drv = to_usb_driver(cintf->dev.driver); 3775 if (drv->pre_reset && drv->post_reset) 3776 unbind = (drv->pre_reset)(cintf); 3777 else if (cintf->condition == 3778 USB_INTERFACE_BOUND) 3779 unbind = 1; 3780 if (unbind) 3781 usb_forced_unbind_intf(cintf); 3782 } 3783 } 3784 } 3785 3786 ret = usb_reset_and_verify_device(udev); 3787 3788 if (config) { 3789 for (i = config->desc.bNumInterfaces - 1; i >= 0; --i) { 3790 struct usb_interface *cintf = config->interface[i]; 3791 struct usb_driver *drv; 3792 int rebind = cintf->needs_binding; 3793 3794 if (!rebind && cintf->dev.driver) { 3795 drv = to_usb_driver(cintf->dev.driver); 3796 if (drv->post_reset) 3797 rebind = (drv->post_reset)(cintf); 3798 else if (cintf->condition == 3799 USB_INTERFACE_BOUND) 3800 rebind = 1; 3801 } 3802 if (ret == 0 && rebind) 3803 usb_rebind_intf(cintf); 3804 } 3805 } 3806 3807 usb_autosuspend_device(udev); 3808 return ret; 3809 } 3810 EXPORT_SYMBOL_GPL(usb_reset_device); 3811 3812 3813 /** 3814 * usb_queue_reset_device - Reset a USB device from an atomic context 3815 * @iface: USB interface belonging to the device to reset 3816 * 3817 * This function can be used to reset a USB device from an atomic 3818 * context, where usb_reset_device() won't work (as it blocks). 3819 * 3820 * Doing a reset via this method is functionally equivalent to calling 3821 * usb_reset_device(), except for the fact that it is delayed to a 3822 * workqueue. This means that any drivers bound to other interfaces 3823 * might be unbound, as well as users from usbfs in user space. 3824 * 3825 * Corner cases: 3826 * 3827 * - Scheduling two resets at the same time from two different drivers 3828 * attached to two different interfaces of the same device is 3829 * possible; depending on how the driver attached to each interface 3830 * handles ->pre_reset(), the second reset might happen or not. 3831 * 3832 * - If a driver is unbound and it had a pending reset, the reset will 3833 * be cancelled. 3834 * 3835 * - This function can be called during .probe() or .disconnect() 3836 * times. On return from .disconnect(), any pending resets will be 3837 * cancelled. 3838 * 3839 * There is no no need to lock/unlock the @reset_ws as schedule_work() 3840 * does its own. 3841 * 3842 * NOTE: We don't do any reference count tracking because it is not 3843 * needed. The lifecycle of the work_struct is tied to the 3844 * usb_interface. Before destroying the interface we cancel the 3845 * work_struct, so the fact that work_struct is queued and or 3846 * running means the interface (and thus, the device) exist and 3847 * are referenced. 3848 */ 3849 void usb_queue_reset_device(struct usb_interface *iface) 3850 { 3851 schedule_work(&iface->reset_ws); 3852 } 3853 EXPORT_SYMBOL_GPL(usb_queue_reset_device); 3854