drivers/usb/core/port.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * usb port device code
   4  *
   5  * Copyright (C) 2012 Intel Corp
   6  *
   7  * Author: Lan Tianyu <[email protected]>
   8  */
   9
  10 #include <linux/kstrtox.h>
  11 #include <linux/slab.h>
  12 #include <linux/pm_qos.h>
  13 #include <linux/component.h>
  14
  15 #include "hub.h"
  16
  17 static int usb_port_block_power_off;
  18
  19 static const struct attribute_group *port_dev_group[];
  20
  21 static ssize_t early_stop_show(struct device *dev,
  22                             struct device_attribute *attr, char *buf)
  23 {
  24         struct usb_port *port_dev = to_usb_port(dev);
  25
  26         return sysfs_emit(buf, "%s\n", port_dev->early_stop ? "yes" : "no");
  27 }
  28
  29 static ssize_t early_stop_store(struct device *dev, struct device_attribute *attr,
  30                                 const char *buf, size_t count)
  31 {
  32         struct usb_port *port_dev = to_usb_port(dev);
  33         bool value;
  34
  35         if (kstrtobool(buf, &value))
  36                 return -EINVAL;
  37
  38         if (value)
  39                 port_dev->early_stop = 1;
  40         else
  41                 port_dev->early_stop = 0;
  42
  43         return count;
  44 }
  45 static DEVICE_ATTR_RW(early_stop);
  46
  47 static ssize_t disable_show(struct device *dev,
  48                               struct device_attribute *attr, char *buf)
  49 {
  50         struct usb_port *port_dev = to_usb_port(dev);
  51         struct usb_device *hdev = to_usb_device(dev->parent->parent);
  52         struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
  53         struct usb_interface *intf = to_usb_interface(hub->intfdev);
  54         int port1 = port_dev->portnum;
  55         u16 portstatus, unused;
  56         bool disabled;
  57         int rc;
  58
  59         rc = usb_autopm_get_interface(intf);
  60         if (rc < 0)
  61                 return rc;
  62
  63         usb_lock_device(hdev);
  64         if (hub->disconnected) {
  65                 rc = -ENODEV;
  66                 goto out_hdev_lock;
  67         }
  68
  69         usb_hub_port_status(hub, port1, &portstatus, &unused);
  70         disabled = !usb_port_is_power_on(hub, portstatus);
  71
  72 out_hdev_lock:
  73         usb_unlock_device(hdev);
  74         usb_autopm_put_interface(intf);
  75
  76         if (rc)
  77                 return rc;
  78
  79         return sysfs_emit(buf, "%s\n", disabled ? "1" : "0");
  80 }
  81
  82 static ssize_t disable_store(struct device *dev, struct device_attribute *attr,
  83                             const char *buf, size_t count)
  84 {
  85         struct usb_port *port_dev = to_usb_port(dev);
  86         struct usb_device *hdev = to_usb_device(dev->parent->parent);
  87         struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
  88         struct usb_interface *intf = to_usb_interface(hub->intfdev);
  89         int port1 = port_dev->portnum;
  90         bool disabled;
  91         int rc;
  92
  93         rc = kstrtobool(buf, &disabled);
  94         if (rc)
  95                 return rc;
  96
  97         rc = usb_autopm_get_interface(intf);
  98         if (rc < 0)
  99                 return rc;
 100
 101         usb_lock_device(hdev);
 102         if (hub->disconnected) {
 103                 rc = -ENODEV;
 104                 goto out_hdev_lock;
 105         }
 106
 107         if (disabled && port_dev->child)
 108                 usb_disconnect(&port_dev->child);
 109
 110         rc = usb_hub_set_port_power(hdev, hub, port1, !disabled);
 111
 112         if (disabled) {
 113                 usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_CONNECTION);
 114                 if (!port_dev->is_superspeed)
 115                         usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_ENABLE);
 116         }
 117
 118         if (!rc)
 119                 rc = count;
 120
 121 out_hdev_lock:
 122         usb_unlock_device(hdev);
 123         usb_autopm_put_interface(intf);
 124
 125         return rc;
 126 }
 127 static DEVICE_ATTR_RW(disable);
 128
 129 static ssize_t location_show(struct device *dev,
 130                              struct device_attribute *attr, char *buf)
 131 {
 132         struct usb_port *port_dev = to_usb_port(dev);
 133
 134         return sprintf(buf, "0x%08x\n", port_dev->location);
 135 }
 136 static DEVICE_ATTR_RO(location);
 137
 138 static ssize_t connect_type_show(struct device *dev,
 139                                  struct device_attribute *attr, char *buf)
 140 {
 141         struct usb_port *port_dev = to_usb_port(dev);
 142         char *result;
 143
 144         switch (port_dev->connect_type) {
 145         case USB_PORT_CONNECT_TYPE_HOT_PLUG:
 146                 result = "hotplug";
 147                 break;
 148         case USB_PORT_CONNECT_TYPE_HARD_WIRED:
 149                 result = "hardwired";
 150                 break;
 151         case USB_PORT_NOT_USED:
 152                 result = "not used";
 153                 break;
 154         default:
 155                 result = "unknown";
 156                 break;
 157         }
 158
 159         return sprintf(buf, "%s\n", result);
 160 }
 161 static DEVICE_ATTR_RO(connect_type);
 162
 163 static ssize_t over_current_count_show(struct device *dev,
 164                                        struct device_attribute *attr, char *buf)
 165 {
 166         struct usb_port *port_dev = to_usb_port(dev);
 167
 168         return sprintf(buf, "%u\n", port_dev->over_current_count);
 169 }
 170 static DEVICE_ATTR_RO(over_current_count);
 171
 172 static ssize_t quirks_show(struct device *dev,
 173                            struct device_attribute *attr, char *buf)
 174 {
 175         struct usb_port *port_dev = to_usb_port(dev);
 176
 177         return sprintf(buf, "%08x\n", port_dev->quirks);
 178 }
 179
 180 static ssize_t quirks_store(struct device *dev, struct device_attribute *attr,
 181                             const char *buf, size_t count)
 182 {
 183         struct usb_port *port_dev = to_usb_port(dev);
 184         u32 value;
 185
 186         if (kstrtou32(buf, 16, &value))
 187                 return -EINVAL;
 188
 189         port_dev->quirks = value;
 190         return count;
 191 }
 192 static DEVICE_ATTR_RW(quirks);
 193
 194 static ssize_t usb3_lpm_permit_show(struct device *dev,
 195                               struct device_attribute *attr, char *buf)
 196 {
 197         struct usb_port *port_dev = to_usb_port(dev);
 198         const char *p;
 199
 200         if (port_dev->usb3_lpm_u1_permit) {
 201                 if (port_dev->usb3_lpm_u2_permit)
 202                         p = "u1_u2";
 203                 else
 204                         p = "u1";
 205         } else {
 206                 if (port_dev->usb3_lpm_u2_permit)
 207                         p = "u2";
 208                 else
 209                         p = "0";
 210         }
 211
 212         return sprintf(buf, "%s\n", p);
 213 }
 214
 215 static ssize_t usb3_lpm_permit_store(struct device *dev,
 216                                struct device_attribute *attr,
 217                                const char *buf, size_t count)
 218 {
 219         struct usb_port *port_dev = to_usb_port(dev);
 220         struct usb_device *udev = port_dev->child;
 221         struct usb_hcd *hcd;
 222
 223         if (!strncmp(buf, "u1_u2", 5)) {
 224                 port_dev->usb3_lpm_u1_permit = 1;
 225                 port_dev->usb3_lpm_u2_permit = 1;
 226
 227         } else if (!strncmp(buf, "u1", 2)) {
 228                 port_dev->usb3_lpm_u1_permit = 1;
 229                 port_dev->usb3_lpm_u2_permit = 0;
 230
 231         } else if (!strncmp(buf, "u2", 2)) {
 232                 port_dev->usb3_lpm_u1_permit = 0;
 233                 port_dev->usb3_lpm_u2_permit = 1;
 234
 235         } else if (!strncmp(buf, "0", 1)) {
 236                 port_dev->usb3_lpm_u1_permit = 0;
 237                 port_dev->usb3_lpm_u2_permit = 0;
 238         } else
 239                 return -EINVAL;
 240
 241         /* If device is connected to the port, disable or enable lpm
 242          * to make new u1 u2 setting take effect immediately.
 243          */
 244         if (udev) {
 245                 hcd = bus_to_hcd(udev->bus);
 246                 if (!hcd)
 247                         return -EINVAL;
 248                 usb_lock_device(udev);
 249                 mutex_lock(hcd->bandwidth_mutex);
 250                 if (!usb_disable_lpm(udev))
 251                         usb_enable_lpm(udev);
 252                 mutex_unlock(hcd->bandwidth_mutex);
 253                 usb_unlock_device(udev);
 254         }
 255
 256         return count;
 257 }
 258 static DEVICE_ATTR_RW(usb3_lpm_permit);
 259
 260 static struct attribute *port_dev_attrs[] = {
 261         &dev_attr_connect_type.attr,
 262         &dev_attr_location.attr,
 263         &dev_attr_quirks.attr,
 264         &dev_attr_over_current_count.attr,
 265         &dev_attr_disable.attr,
 266         &dev_attr_early_stop.attr,
 267         NULL,
 268 };
 269
 270 static const struct attribute_group port_dev_attr_grp = {
 271         .attrs = port_dev_attrs,
 272 };
 273
 274 static const struct attribute_group *port_dev_group[] = {
 275         &port_dev_attr_grp,
 276         NULL,
 277 };
 278
 279 static struct attribute *port_dev_usb3_attrs[] = {
 280         &dev_attr_usb3_lpm_permit.attr,
 281         NULL,
 282 };
 283
 284 static const struct attribute_group port_dev_usb3_attr_grp = {
 285         .attrs = port_dev_usb3_attrs,
 286 };
 287
 288 static const struct attribute_group *port_dev_usb3_group[] = {
 289         &port_dev_attr_grp,
 290         &port_dev_usb3_attr_grp,
 291         NULL,
 292 };
 293
 294 static void usb_port_device_release(struct device *dev)
 295 {
 296         struct usb_port *port_dev = to_usb_port(dev);
 297
 298         kfree(port_dev->req);
 299         kfree(port_dev);
 300 }
 301
 302 #ifdef CONFIG_PM
 303 static int usb_port_runtime_resume(struct device *dev)
 304 {
 305         struct usb_port *port_dev = to_usb_port(dev);
 306         struct usb_device *hdev = to_usb_device(dev->parent->parent);
 307         struct usb_interface *intf = to_usb_interface(dev->parent);
 308         struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
 309         struct usb_device *udev = port_dev->child;
 310         struct usb_port *peer = port_dev->peer;
 311         int port1 = port_dev->portnum;
 312         int retval;
 313
 314         if (!hub)
 315                 return -EINVAL;
 316         if (hub->in_reset) {
 317                 set_bit(port1, hub->power_bits);
 318                 return 0;
 319         }
 320
 321         /*
 322          * Power on our usb3 peer before this usb2 port to prevent a usb3
 323          * device from degrading to its usb2 connection
 324          */
 325         if (!port_dev->is_superspeed && peer)
 326                 pm_runtime_get_sync(&peer->dev);
 327
 328         retval = usb_autopm_get_interface(intf);
 329         if (retval < 0)
 330                 return retval;
 331
 332         retval = usb_hub_set_port_power(hdev, hub, port1, true);
 333         msleep(hub_power_on_good_delay(hub));
 334         if (udev && !retval) {
 335                 /*
 336                  * Our preference is to simply wait for the port to reconnect,
 337                  * as that is the lowest latency method to restart the port.
 338                  * However, there are cases where toggling port power results in
 339                  * the host port and the device port getting out of sync causing
 340                  * a link training live lock.  Upon timeout, flag the port as
 341                  * needing warm reset recovery (to be performed later by
 342                  * usb_port_resume() as requested via usb_wakeup_notification())
 343                  */
 344                 if (hub_port_debounce_be_connected(hub, port1) < 0) {
 345                         dev_dbg(&port_dev->dev, "reconnect timeout\n");
 346                         if (hub_is_superspeed(hdev))
 347                                 set_bit(port1, hub->warm_reset_bits);
 348                 }
 349
 350                 /* Force the child awake to revalidate after the power loss. */
 351                 if (!test_and_set_bit(port1, hub->child_usage_bits)) {
 352                         pm_runtime_get_noresume(&port_dev->dev);
 353                         pm_request_resume(&udev->dev);
 354                 }
 355         }
 356
 357         usb_autopm_put_interface(intf);
 358
 359         return retval;
 360 }
 361
 362 static int usb_port_runtime_suspend(struct device *dev)
 363 {
 364         struct usb_port *port_dev = to_usb_port(dev);
 365         struct usb_device *hdev = to_usb_device(dev->parent->parent);
 366         struct usb_interface *intf = to_usb_interface(dev->parent);
 367         struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
 368         struct usb_port *peer = port_dev->peer;
 369         int port1 = port_dev->portnum;
 370         int retval;
 371
 372         if (!hub)
 373                 return -EINVAL;
 374         if (hub->in_reset)
 375                 return -EBUSY;
 376
 377         if (dev_pm_qos_flags(&port_dev->dev, PM_QOS_FLAG_NO_POWER_OFF)
 378                         == PM_QOS_FLAGS_ALL)
 379                 return -EAGAIN;
 380
 381         if (usb_port_block_power_off)
 382                 return -EBUSY;
 383
 384         retval = usb_autopm_get_interface(intf);
 385         if (retval < 0)
 386                 return retval;
 387
 388         retval = usb_hub_set_port_power(hdev, hub, port1, false);
 389         usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_CONNECTION);
 390         if (!port_dev->is_superspeed)
 391                 usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_ENABLE);
 392         usb_autopm_put_interface(intf);
 393
 394         /*
 395          * Our peer usb3 port may now be able to suspend, so
 396          * asynchronously queue a suspend request to observe that this
 397          * usb2 port is now off.
 398          */
 399         if (!port_dev->is_superspeed && peer)
 400                 pm_runtime_put(&peer->dev);
 401
 402         return retval;
 403 }
 404 #endif
 405
 406 static void usb_port_shutdown(struct device *dev)
 407 {
 408         struct usb_port *port_dev = to_usb_port(dev);
 409
 410         if (port_dev->child)
 411                 usb_disable_usb2_hardware_lpm(port_dev->child);
 412 }
 413
 414 static const struct dev_pm_ops usb_port_pm_ops = {
 415 #ifdef CONFIG_PM
 416         .runtime_suspend =      usb_port_runtime_suspend,
 417         .runtime_resume =       usb_port_runtime_resume,
 418 #endif
 419 };
 420
 421 struct device_type usb_port_device_type = {
 422         .name =         "usb_port",
 423         .release =      usb_port_device_release,
 424         .pm =           &usb_port_pm_ops,
 425 };
 426
 427 static struct device_driver usb_port_driver = {
 428         .name = "usb",
 429         .owner = THIS_MODULE,
 430         .shutdown = usb_port_shutdown,
 431 };
 432
 433 static int link_peers(struct usb_port *left, struct usb_port *right)
 434 {
 435         struct usb_port *ss_port, *hs_port;
 436         int rc;
 437
 438         if (left->peer == right && right->peer == left)
 439                 return 0;
 440
 441         if (left->peer || right->peer) {
 442                 struct usb_port *lpeer = left->peer;
 443                 struct usb_port *rpeer = right->peer;
 444                 char *method;
 445
 446                 if (left->location && left->location == right->location)
 447                         method = "location";
 448                 else
 449                         method = "default";
 450
 451                 pr_debug("usb: failed to peer %s and %s by %s (%s:%s) (%s:%s)\n",
 452                         dev_name(&left->dev), dev_name(&right->dev), method,
 453                         dev_name(&left->dev),
 454                         lpeer ? dev_name(&lpeer->dev) : "none",
 455                         dev_name(&right->dev),
 456                         rpeer ? dev_name(&rpeer->dev) : "none");
 457                 return -EBUSY;
 458         }
 459
 460         rc = sysfs_create_link(&left->dev.kobj, &right->dev.kobj, "peer");
 461         if (rc)
 462                 return rc;
 463         rc = sysfs_create_link(&right->dev.kobj, &left->dev.kobj, "peer");
 464         if (rc) {
 465                 sysfs_remove_link(&left->dev.kobj, "peer");
 466                 return rc;
 467         }
 468
 469         /*
 470          * We need to wake the HiSpeed port to make sure we don't race
 471          * setting ->peer with usb_port_runtime_suspend().  Otherwise we
 472          * may miss a suspend event for the SuperSpeed port.
 473          */
 474         if (left->is_superspeed) {
 475                 ss_port = left;
 476                 WARN_ON(right->is_superspeed);
 477                 hs_port = right;
 478         } else {
 479                 ss_port = right;
 480                 WARN_ON(!right->is_superspeed);
 481                 hs_port = left;
 482         }
 483         pm_runtime_get_sync(&hs_port->dev);
 484
 485         left->peer = right;
 486         right->peer = left;
 487
 488         /*
 489          * The SuperSpeed reference is dropped when the HiSpeed port in
 490          * this relationship suspends, i.e. when it is safe to allow a
 491          * SuperSpeed connection to drop since there is no risk of a
 492          * device degrading to its powered-off HiSpeed connection.
 493          *
 494          * Also, drop the HiSpeed ref taken above.
 495          */
 496         pm_runtime_get_sync(&ss_port->dev);
 497         pm_runtime_put(&hs_port->dev);
 498
 499         return 0;
 500 }
 501
 502 static void link_peers_report(struct usb_port *left, struct usb_port *right)
 503 {
 504         int rc;
 505
 506         rc = link_peers(left, right);
 507         if (rc == 0) {
 508                 dev_dbg(&left->dev, "peered to %s\n", dev_name(&right->dev));
 509         } else {
 510                 dev_dbg(&left->dev, "failed to peer to %s (%d)\n",
 511                                 dev_name(&right->dev), rc);
 512                 pr_warn_once("usb: port power management may be unreliable\n");
 513                 usb_port_block_power_off = 1;
 514         }
 515 }
 516
 517 static void unlink_peers(struct usb_port *left, struct usb_port *right)
 518 {
 519         struct usb_port *ss_port, *hs_port;
 520
 521         WARN(right->peer != left || left->peer != right,
 522                         "%s and %s are not peers?\n",
 523                         dev_name(&left->dev), dev_name(&right->dev));
 524
 525         /*
 526          * We wake the HiSpeed port to make sure we don't race its
 527          * usb_port_runtime_resume() event which takes a SuperSpeed ref
 528          * when ->peer is !NULL.
 529          */
 530         if (left->is_superspeed) {
 531                 ss_port = left;
 532                 hs_port = right;
 533         } else {
 534                 ss_port = right;
 535                 hs_port = left;
 536         }
 537
 538         pm_runtime_get_sync(&hs_port->dev);
 539
 540         sysfs_remove_link(&left->dev.kobj, "peer");
 541         right->peer = NULL;
 542         sysfs_remove_link(&right->dev.kobj, "peer");
 543         left->peer = NULL;
 544
 545         /* Drop the SuperSpeed ref held on behalf of the active HiSpeed port */
 546         pm_runtime_put(&ss_port->dev);
 547
 548         /* Drop the ref taken above */
 549         pm_runtime_put(&hs_port->dev);
 550 }
 551
 552 /*
 553  * For each usb hub device in the system check to see if it is in the
 554  * peer domain of the given port_dev, and if it is check to see if it
 555  * has a port that matches the given port by location
 556  */
 557 static int match_location(struct usb_device *peer_hdev, void *p)
 558 {
 559         int port1;
 560         struct usb_hcd *hcd, *peer_hcd;
 561         struct usb_port *port_dev = p, *peer;
 562         struct usb_hub *peer_hub = usb_hub_to_struct_hub(peer_hdev);
 563         struct usb_device *hdev = to_usb_device(port_dev->dev.parent->parent);
 564
 565         if (!peer_hub)
 566                 return 0;
 567
 568         hcd = bus_to_hcd(hdev->bus);
 569         peer_hcd = bus_to_hcd(peer_hdev->bus);
 570         /* peer_hcd is provisional until we verify it against the known peer */
 571         if (peer_hcd != hcd->shared_hcd)
 572                 return 0;
 573
 574         for (port1 = 1; port1 <= peer_hdev->maxchild; port1++) {
 575                 peer = peer_hub->ports[port1 - 1];
 576                 if (peer && peer->location == port_dev->location) {
 577                         link_peers_report(port_dev, peer);
 578                         return 1; /* done */
 579                 }
 580         }
 581
 582         return 0;
 583 }
 584
 585 /*
 586  * Find the peer port either via explicit platform firmware "location"
 587  * data, the peer hcd for root hubs, or the upstream peer relationship
 588  * for all other hubs.
 589  */
 590 static void find_and_link_peer(struct usb_hub *hub, int port1)
 591 {
 592         struct usb_port *port_dev = hub->ports[port1 - 1], *peer;
 593         struct usb_device *hdev = hub->hdev;
 594         struct usb_device *peer_hdev;
 595         struct usb_hub *peer_hub;
 596
 597         /*
 598          * If location data is available then we can only peer this port
 599          * by a location match, not the default peer (lest we create a
 600          * situation where we need to go back and undo a default peering
 601          * when the port is later peered by location data)
 602          */
 603         if (port_dev->location) {
 604                 /* we link the peer in match_location() if found */
 605                 usb_for_each_dev(port_dev, match_location);
 606                 return;
 607         } else if (!hdev->parent) {
 608                 struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
 609                 struct usb_hcd *peer_hcd = hcd->shared_hcd;
 610
 611                 if (!peer_hcd)
 612                         return;
 613
 614                 peer_hdev = peer_hcd->self.root_hub;
 615         } else {
 616                 struct usb_port *upstream;
 617                 struct usb_device *parent = hdev->parent;
 618                 struct usb_hub *parent_hub = usb_hub_to_struct_hub(parent);
 619
 620                 if (!parent_hub)
 621                         return;
 622
 623                 upstream = parent_hub->ports[hdev->portnum - 1];
 624                 if (!upstream || !upstream->peer)
 625                         return;
 626
 627                 peer_hdev = upstream->peer->child;
 628         }
 629
 630         peer_hub = usb_hub_to_struct_hub(peer_hdev);
 631         if (!peer_hub || port1 > peer_hdev->maxchild)
 632                 return;
 633
 634         /*
 635          * we found a valid default peer, last check is to make sure it
 636          * does not have location data
 637          */
 638         peer = peer_hub->ports[port1 - 1];
 639         if (peer && peer->location == 0)
 640                 link_peers_report(port_dev, peer);
 641 }
 642
 643 static int connector_bind(struct device *dev, struct device *connector, void *data)
 644 {
 645         int ret;
 646
 647         ret = sysfs_create_link(&dev->kobj, &connector->kobj, "connector");
 648         if (ret)
 649                 return ret;
 650
 651         ret = sysfs_create_link(&connector->kobj, &dev->kobj, dev_name(dev));
 652         if (ret)
 653                 sysfs_remove_link(&dev->kobj, "connector");
 654
 655         return ret;
 656 }
 657
 658 static void connector_unbind(struct device *dev, struct device *connector, void *data)
 659 {
 660         sysfs_remove_link(&connector->kobj, dev_name(dev));
 661         sysfs_remove_link(&dev->kobj, "connector");
 662 }
 663
 664 static const struct component_ops connector_ops = {
 665         .bind = connector_bind,
 666         .unbind = connector_unbind,
 667 };
 668
 669 int usb_hub_create_port_device(struct usb_hub *hub, int port1)
 670 {
 671         struct usb_port *port_dev;
 672         struct usb_device *hdev = hub->hdev;
 673         int retval;
 674
 675         port_dev = kzalloc(sizeof(*port_dev), GFP_KERNEL);
 676         if (!port_dev)
 677                 return -ENOMEM;
 678
 679         port_dev->req = kzalloc(sizeof(*(port_dev->req)), GFP_KERNEL);
 680         if (!port_dev->req) {
 681                 kfree(port_dev);
 682                 return -ENOMEM;
 683         }
 684
 685         hub->ports[port1 - 1] = port_dev;
 686         port_dev->portnum = port1;
 687         set_bit(port1, hub->power_bits);
 688         port_dev->dev.parent = hub->intfdev;
 689         if (hub_is_superspeed(hdev)) {
 690                 port_dev->usb3_lpm_u1_permit = 1;
 691                 port_dev->usb3_lpm_u2_permit = 1;
 692                 port_dev->dev.groups = port_dev_usb3_group;
 693         } else
 694                 port_dev->dev.groups = port_dev_group;
 695         port_dev->dev.type = &usb_port_device_type;
 696         port_dev->dev.driver = &usb_port_driver;
 697         if (hub_is_superspeed(hub->hdev))
 698                 port_dev->is_superspeed = 1;
 699         dev_set_name(&port_dev->dev, "%s-port%d", dev_name(&hub->hdev->dev),
 700                         port1);
 701         mutex_init(&port_dev->status_lock);
 702         retval = device_register(&port_dev->dev);
 703         if (retval) {
 704                 put_device(&port_dev->dev);
 705                 return retval;
 706         }
 707
 708         /* Set default policy of port-poweroff disabled. */
 709         retval = dev_pm_qos_add_request(&port_dev->dev, port_dev->req,
 710                         DEV_PM_QOS_FLAGS, PM_QOS_FLAG_NO_POWER_OFF);
 711         if (retval < 0) {
 712                 device_unregister(&port_dev->dev);
 713                 return retval;
 714         }
 715
 716         retval = component_add(&port_dev->dev, &connector_ops);
 717         if (retval) {
 718                 dev_warn(&port_dev->dev, "failed to add component\n");
 719                 device_unregister(&port_dev->dev);
 720                 return retval;
 721         }
 722
 723         find_and_link_peer(hub, port1);
 724
 725         /*
 726          * Enable runtime pm and hold a refernce that hub_configure()
 727          * will drop once the PM_QOS_NO_POWER_OFF flag state has been set
 728          * and the hub has been fully registered (hdev->maxchild set).
 729          */
 730         pm_runtime_set_active(&port_dev->dev);
 731         pm_runtime_get_noresume(&port_dev->dev);
 732         pm_runtime_enable(&port_dev->dev);
 733         device_enable_async_suspend(&port_dev->dev);
 734
 735         /*
 736          * Keep hidden the ability to enable port-poweroff if the hub
 737          * does not support power switching.
 738          */
 739         if (!hub_is_port_power_switchable(hub))
 740                 return 0;
 741
 742         /* Attempt to let userspace take over the policy. */
 743         retval = dev_pm_qos_expose_flags(&port_dev->dev,
 744                         PM_QOS_FLAG_NO_POWER_OFF);
 745         if (retval < 0) {
 746                 dev_warn(&port_dev->dev, "failed to expose pm_qos_no_poweroff\n");
 747                 return 0;
 748         }
 749
 750         /* Userspace owns the policy, drop the kernel 'no_poweroff' request. */
 751         retval = dev_pm_qos_remove_request(port_dev->req);
 752         if (retval >= 0) {
 753                 kfree(port_dev->req);
 754                 port_dev->req = NULL;
 755         }
 756         return 0;
 757 }
 758
 759 void usb_hub_remove_port_device(struct usb_hub *hub, int port1)
 760 {
 761         struct usb_port *port_dev = hub->ports[port1 - 1];
 762         struct usb_port *peer;
 763
 764         peer = port_dev->peer;
 765         if (peer)
 766                 unlink_peers(port_dev, peer);
 767         component_del(&port_dev->dev, &connector_ops);
 768         device_unregister(&port_dev->dev);
 769 }