1What: /sys/bus/usb/devices/<INTERFACE>/authorized 2Date: August 2015 3Description: 4 This allows to authorize (1) or deauthorize (0) 5 individual interfaces instead a whole device 6 in contrast to the device authorization. 7 If a deauthorized interface will be authorized 8 so the driver probing must be triggered manually 9 by writing INTERFACE to /sys/bus/usb/drivers_probe 10 This allows to avoid side-effects with drivers 11 that need multiple interfaces. 12 13 A deauthorized interface cannot be probed or claimed. 14 15What: /sys/bus/usb/devices/usbX/interface_authorized_default 16Date: August 2015 17Description: 18 This is used as value that determines if interfaces 19 would be authorized by default. 20 The value can be 1 or 0. It's by default 1. 21 22What: /sys/bus/usb/device/.../authorized 23Date: July 2008 24KernelVersion: 2.6.26 25Contact: David Vrabel <david.vrabel@csr.com> 26Description: 27 Authorized devices are available for use by device 28 drivers, non-authorized one are not. By default, wired 29 USB devices are authorized. 30 31 Certified Wireless USB devices are not authorized 32 initially and should be (by writing 1) after the 33 device has been authenticated. 34 35What: /sys/bus/usb/device/.../wusb_cdid 36Date: July 2008 37KernelVersion: 2.6.27 38Contact: David Vrabel <david.vrabel@csr.com> 39Description: 40 For Certified Wireless USB devices only. 41 42 A devices's CDID, as 16 space-separated hex octets. 43 44What: /sys/bus/usb/device/.../wusb_ck 45Date: July 2008 46KernelVersion: 2.6.27 47Contact: David Vrabel <david.vrabel@csr.com> 48Description: 49 For Certified Wireless USB devices only. 50 51 Write the device's connection key (CK) to start the 52 authentication of the device. The CK is 16 53 space-separated hex octets. 54 55What: /sys/bus/usb/device/.../wusb_disconnect 56Date: July 2008 57KernelVersion: 2.6.27 58Contact: David Vrabel <david.vrabel@csr.com> 59Description: 60 For Certified Wireless USB devices only. 61 62 Write a 1 to force the device to disconnect 63 (equivalent to unplugging a wired USB device). 64 65What: /sys/bus/usb/drivers/.../new_id 66Date: October 2011 67Contact: linux-usb@vger.kernel.org 68Description: 69 Writing a device ID to this file will attempt to 70 dynamically add a new device ID to a USB device driver. 71 This may allow the driver to support more hardware than 72 was included in the driver's static device ID support 73 table at compile time. The format for the device ID is: 74 idVendor idProduct bInterfaceClass RefIdVendor RefIdProduct 75 The vendor ID and device ID fields are required, the 76 rest is optional. The `Ref*` tuple can be used to tell the 77 driver to use the same driver_data for the new device as 78 it is used for the reference device. 79 Upon successfully adding an ID, the driver will probe 80 for the device and attempt to bind to it. For example:: 81 82 # echo "8086 10f5" > /sys/bus/usb/drivers/foo/new_id 83 84 Here add a new device (0458:7045) using driver_data from 85 an already supported device (0458:704c):: 86 87 # echo "0458 7045 0 0458 704c" > /sys/bus/usb/drivers/foo/new_id 88 89 Reading from this file will list all dynamically added 90 device IDs in the same format, with one entry per 91 line. For example:: 92 93 # cat /sys/bus/usb/drivers/foo/new_id 94 8086 10f5 95 dead beef 06 96 f00d cafe 97 98 The list will be truncated at PAGE_SIZE bytes due to 99 sysfs restrictions. 100 101What: /sys/bus/usb-serial/drivers/.../new_id 102Date: October 2011 103Contact: linux-usb@vger.kernel.org 104Description: 105 For serial USB drivers, this attribute appears under the 106 extra bus folder "usb-serial" in sysfs; apart from that 107 difference, all descriptions from the entry 108 "/sys/bus/usb/drivers/.../new_id" apply. 109 110What: /sys/bus/usb/drivers/.../remove_id 111Date: November 2009 112Contact: CHENG Renquan <rqcheng@smu.edu.sg> 113Description: 114 Writing a device ID to this file will remove an ID 115 that was dynamically added via the new_id sysfs entry. 116 The format for the device ID is: 117 idVendor idProduct. After successfully 118 removing an ID, the driver will no longer support the 119 device. This is useful to ensure auto probing won't 120 match the driver to the device. For example: 121 # echo "046d c315" > /sys/bus/usb/drivers/foo/remove_id 122 123 Reading from this file will list the dynamically added 124 device IDs, exactly like reading from the entry 125 "/sys/bus/usb/drivers/.../new_id" 126 127What: /sys/bus/usb/devices/.../power/usb2_hardware_lpm 128Date: September 2011 129Contact: Andiry Xu <andiry.xu@amd.com> 130Description: 131 If CONFIG_PM is set and a USB 2.0 lpm-capable device is plugged 132 in to a xHCI host which support link PM, it will perform a LPM 133 test; if the test is passed and host supports USB2 hardware LPM 134 (xHCI 1.0 feature), USB2 hardware LPM will be enabled for the 135 device and the USB device directory will contain a file named 136 power/usb2_hardware_lpm. The file holds a string value (enable 137 or disable) indicating whether or not USB2 hardware LPM is 138 enabled for the device. Developer can write y/Y/1 or n/N/0 to 139 the file to enable/disable the feature. 140 141What: /sys/bus/usb/devices/.../power/usb3_hardware_lpm_u1 142 /sys/bus/usb/devices/.../power/usb3_hardware_lpm_u2 143Date: November 2015 144Contact: Kevin Strasser <kevin.strasser@linux.intel.com> 145 Lu Baolu <baolu.lu@linux.intel.com> 146Description: 147 If CONFIG_PM is set and a USB 3.0 lpm-capable device is plugged 148 in to a xHCI host which supports link PM, it will check if U1 149 and U2 exit latencies have been set in the BOS descriptor; if 150 the check is passed and the host supports USB3 hardware LPM, 151 USB3 hardware LPM will be enabled for the device and the USB 152 device directory will contain two files named 153 power/usb3_hardware_lpm_u1 and power/usb3_hardware_lpm_u2. These 154 files hold a string value (enable or disable) indicating whether 155 or not USB3 hardware LPM U1 or U2 is enabled for the device. 156 157What: /sys/bus/usb/devices/.../ltm_capable 158Date: July 2012 159Contact: Sarah Sharp <sarah.a.sharp@linux.intel.com> 160Description: 161 USB 3.0 devices may optionally support Latency Tolerance 162 Messaging (LTM). They indicate their support by setting a bit 163 in the bmAttributes field of their SuperSpeed BOS descriptors. 164 If that bit is set for the device, ltm_capable will read "yes". 165 If the device doesn't support LTM, the file will read "no". 166 The file will be present for all speeds of USB devices, and will 167 always read "no" for USB 1.1 and USB 2.0 devices. 168 169What: /sys/bus/usb/devices/.../<hub_interface>/port<X> 170Date: August 2012 171Contact: Lan Tianyu <tianyu.lan@intel.com> 172Description: 173 The /sys/bus/usb/devices/.../<hub_interface>/port<X> 174 is usb port device's sysfs directory. 175 176What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/connect_type 177Date: January 2013 178Contact: Lan Tianyu <tianyu.lan@intel.com> 179Description: 180 Some platforms provide usb port connect types through ACPI. 181 This attribute is to expose these information to user space. 182 The file will read "hotplug", "hardwired" and "not used" if the 183 information is available, and "unknown" otherwise. 184 185What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/location 186Date: October 2018 187Contact: Bjørn Mork <bjorn@mork.no> 188Description: 189 Some platforms provide usb port physical location through 190 firmware. This is used by the kernel to pair up logical ports 191 mapping to the same physical connector. The attribute exposes the 192 raw location value as a hex integer. 193 194 195What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/quirks 196Date: May 2018 197Contact: Nicolas Boichat <drinkcat@chromium.org> 198Description: 199 In some cases, we care about time-to-active for devices 200 connected on a specific port (e.g. non-standard USB port like 201 pogo pins), where the device to be connected is known in 202 advance, and behaves well according to the specification. 203 This attribute is a bit-field that controls the behavior of 204 a specific port: 205 206 - Bit 0 of this field selects the "old" enumeration scheme, 207 as it is considerably faster (it only causes one USB reset 208 instead of 2). 209 210 The old enumeration scheme can also be selected globally 211 using /sys/module/usbcore/parameters/old_scheme_first, but 212 it is often not desirable as the new scheme was introduced to 213 increase compatibility with more devices. 214 - Bit 1 reduces TRSTRCY to the 10 ms that are required by the 215 USB 2.0 specification, instead of the 50 ms that are normally 216 used to help make enumeration work better on some high speed 217 devices. 218 219What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/over_current_count 220Date: February 2018 221Contact: Richard Leitner <richard.leitner@skidata.com> 222Description: 223 Most hubs are able to detect over-current situations on their 224 ports and report them to the kernel. This attribute is to expose 225 the number of over-current situation occurred on a specific port 226 to user space. This file will contain an unsigned 32 bit value 227 which wraps to 0 after its maximum is reached. This file supports 228 poll() for monitoring changes to this value in user space. 229 230 Any time this value changes the corresponding hub device will send a 231 udev event with the following attributes:: 232 233 OVER_CURRENT_PORT=/sys/bus/usb/devices/.../<hub_interface>/port<X> 234 OVER_CURRENT_COUNT=[current value of this sysfs attribute] 235 236What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/usb3_lpm_permit 237Date: November 2015 238Contact: Lu Baolu <baolu.lu@linux.intel.com> 239Description: 240 Some USB3.0 devices are not friendly to USB3 LPM. usb3_lpm_permit 241 attribute allows enabling/disabling usb3 lpm of a port. It takes 242 effect both before and after a usb device is enumerated. Supported 243 values are "0" if both u1 and u2 are NOT permitted, "u1" if only u1 244 is permitted, "u2" if only u2 is permitted, "u1_u2" if both u1 and 245 u2 are permitted. 246 247What: /sys/bus/usb/devices/.../power/usb2_lpm_l1_timeout 248Date: May 2013 249Contact: Mathias Nyman <mathias.nyman@linux.intel.com> 250Description: 251 USB 2.0 devices may support hardware link power management (LPM) 252 L1 sleep state. The usb2_lpm_l1_timeout attribute allows 253 tuning the timeout for L1 inactivity timer (LPM timer), e.g. 254 needed inactivity time before host requests the device to go to L1 sleep. 255 Useful for power management tuning. 256 Supported values are 0 - 65535 microseconds. 257 258What: /sys/bus/usb/devices/.../power/usb2_lpm_besl 259Date: May 2013 260Contact: Mathias Nyman <mathias.nyman@linux.intel.com> 261Description: 262 USB 2.0 devices that support hardware link power management (LPM) 263 L1 sleep state now use a best effort service latency value (BESL) to 264 indicate the best effort to resumption of service to the device after the 265 initiation of the resume event. 266 If the device does not have a preferred besl value then the host can select 267 one instead. This usb2_lpm_besl attribute allows to tune the host selected besl 268 value in order to tune power saving and service latency. 269 270 Supported values are 0 - 15. 271 More information on how besl values map to microseconds can be found in 272 USB 2.0 ECN Errata for Link Power Management, section 4.10) 273 274What: /sys/bus/usb/devices/.../rx_lanes 275Date: March 2018 276Contact: Mathias Nyman <mathias.nyman@linux.intel.com> 277Description: 278 Number of rx lanes the device is using. 279 USB 3.2 adds Dual-lane support, 2 rx and 2 tx lanes over Type-C. 280 Inter-Chip SSIC devices support asymmetric lanes up to 4 lanes per 281 direction. Devices before USB 3.2 are single lane (rx_lanes = 1) 282 283What: /sys/bus/usb/devices/.../tx_lanes 284Date: March 2018 285Contact: Mathias Nyman <mathias.nyman@linux.intel.com> 286Description: 287 Number of tx lanes the device is using. 288 USB 3.2 adds Dual-lane support, 2 rx and 2 tx -lanes over Type-C. 289 Inter-Chip SSIC devices support asymmetric lanes up to 4 lanes per 290 direction. Devices before USB 3.2 are single lane (tx_lanes = 1) 291 292What: /sys/bus/usb/devices/usbX/bAlternateSetting 293Description: 294 The current interface alternate setting number, in decimal. 295 296 See USB specs for its meaning. 297 298What: /sys/bus/usb/devices/usbX/bcdDevice 299Description: 300 The device's release number, in hexadecimal. 301 302 See USB specs for its meaning. 303 304What: /sys/bus/usb/devices/usbX/bConfigurationValue 305Description: 306 While a USB device typically have just one configuration 307 setting, some devices support multiple configurations. 308 309 This value shows the current configuration, in decimal. 310 311 Changing its value will change the device's configuration 312 to another setting. 313 314 The number of configurations supported by a device is at: 315 316 /sys/bus/usb/devices/usbX/bNumConfigurations 317 318 See USB specs for its meaning. 319 320What: /sys/bus/usb/devices/usbX/bDeviceClass 321Description: 322 Class code of the device, in hexadecimal. 323 324 See USB specs for its meaning. 325 326What: /sys/bus/usb/devices/usbX/bDeviceProtocol 327Description: 328 Protocol code of the device, in hexadecimal. 329 330 See USB specs for its meaning. 331 332What: /sys/bus/usb/devices/usbX/bDeviceSubClass 333Description: 334 Subclass code of the device, in hexadecimal. 335 336 See USB specs for its meaning. 337 338What: /sys/bus/usb/devices/usbX/bInterfaceClass 339Description: 340 Class code of the interface, in hexadecimal. 341 342 See USB specs for its meaning. 343 344What: /sys/bus/usb/devices/usbX/bInterfaceNumber 345Description: 346 Interface number, in hexadecimal. 347 348 See USB specs for its meaning. 349 350What: /sys/bus/usb/devices/usbX/bInterfaceProtocol 351Description: 352 Protocol code of the interface, in hexadecimal. 353 354 See USB specs for its meaning. 355 356What: /sys/bus/usb/devices/usbX/bInterfaceSubClass 357Description: 358 Subclass code of the interface, in hexadecimal. 359 360 See USB specs for its meaning. 361 362What: /sys/bus/usb/devices/usbX/bmAttributes 363Description: 364 Attributes of the current configuration, in hexadecimal. 365 366 See USB specs for its meaning. 367 368What: /sys/bus/usb/devices/usbX/bMaxPacketSize0 369Description: 370 Maximum endpoint 0 packet size, in decimal. 371 372 See USB specs for its meaning. 373 374What: /sys/bus/usb/devices/usbX/bMaxPower 375Description: 376 Maximum power consumption of the active configuration of 377 the device, in miliamperes. 378 379What: /sys/bus/usb/devices/usbX/bNumConfigurations 380Description: 381 Number of the possible configurations of the device, in 382 decimal. The current configuration is controlled via: 383 384 /sys/bus/usb/devices/usbX/bConfigurationValue 385 386 See USB specs for its meaning. 387 388What: /sys/bus/usb/devices/usbX/bNumEndpoints 389Description: 390 Number of endpoints used on this interface, in hexadecimal. 391 392 See USB specs for its meaning. 393 394What: /sys/bus/usb/devices/usbX/bNumInterfaces 395Description: 396 Number of interfaces on this device, in decimal. 397 398What: /sys/bus/usb/devices/usbX/busnum 399Description: 400 Number of the bus. 401 402What: /sys/bus/usb/devices/usbX/configuration 403Description: 404 Contents of the string descriptor associated with the 405 current configuration. It may include the firmware version 406 of a device and/or its serial number. 407 408What: /sys/bus/usb/devices/usbX/descriptors 409Description: 410 Contains the interface descriptors, in binary. 411 412What: /sys/bus/usb/devices/usbX/idProduct 413Description: 414 Product ID, in hexadecimal. 415 416What: /sys/bus/usb/devices/usbX/idVendor 417Description: 418 Vendor ID, in hexadecimal. 419 420What: /sys/bus/usb/devices/usbX/devspec 421Description: 422 Displays the Device Tree Open Firmware node of the interface. 423 424What: /sys/bus/usb/devices/usbX/avoid_reset_quirk 425Description: 426 Most devices have this set to zero. 427 428 If the value is 1, enable a USB quirk that prevents this 429 device to use reset. 430 431 (read/write) 432 433What: /sys/bus/usb/devices/usbX/devnum 434Description: 435 USB interface device number, in decimal. 436 437What: /sys/bus/usb/devices/usbX/devpath 438Description: 439 String containing the USB interface device path. 440 441What: /sys/bus/usb/devices/usbX/manufacturer 442Description: 443 Vendor specific string containing the name of the 444 manufacturer of the device. 445 446What: /sys/bus/usb/devices/usbX/maxchild 447Description: 448 Number of ports of an USB hub 449 450What: /sys/bus/usb/devices/usbX/persist 451Description: 452 Keeps the device even if it gets disconnected. 453 454What: /sys/bus/usb/devices/usbX/product 455Description: 456 Vendor specific string containing the name of the 457 device's product. 458 459What: /sys/bus/usb/devices/usbX/speed 460Description: 461 Shows the device's max speed, according to the USB version, 462 in Mbps. 463 Can be: 464 465 ======= ==================== 466 Unknown speed unknown 467 1.5 Low speed 468 15 Full speed 469 480 High Speed 470 5000 Super Speed 471 10000 Super Speed+ 472 20000 Super Speed+ Gen 2x2 473 ======= ==================== 474 475What: /sys/bus/usb/devices/usbX/supports_autosuspend 476Description: 477 Returns 1 if the device doesn't support autosuspend. 478 Otherwise, returns 0. 479 480What: /sys/bus/usb/devices/usbX/urbnum 481Description: 482 Number of URBs submitted for the whole device. 483 484What: /sys/bus/usb/devices/usbX/version 485Description: 486 String containing the USB device version, as encoded 487 at the BCD descriptor. 488 489What: /sys/bus/usb/devices/usbX/power/autosuspend 490Description: 491 Time in milliseconds for the device to autosuspend. If the 492 value is negative, then autosuspend is prevented. 493 494 (read/write) 495 496What: /sys/bus/usb/devices/usbX/power/active_duration 497Description: 498 The total time the device has not been suspended. 499 500What: /sys/bus/usb/devices/usbX/power/connected_duration 501Description: 502 The total time (in msec) that the device has been connected. 503 504What: /sys/bus/usb/devices/usbX/power/level 505Description: 506 507What: /sys/bus/usb/devices/usbX/ep_<N>/bEndpointAddress 508Description: 509 The address of the endpoint described by this descriptor, 510 in hexadecimal. The endpoint direction on this bitmapped field 511 is also shown at: 512 513 /sys/bus/usb/devices/usbX/ep_<N>/direction 514 515 See USB specs for its meaning. 516 517What: /sys/bus/usb/devices/usbX/ep_<N>/bInterval 518Description: 519 The interval of the endpoint as described on its descriptor, 520 in hexadecimal. The actual interval depends on the version 521 of the USB. Also shown in time units at 522 /sys/bus/usb/devices/usbX/ep_<N>/interval. 523 524What: /sys/bus/usb/devices/usbX/ep_<N>/bLength 525Description: 526 Number of bytes of the endpoint descriptor, in hexadecimal. 527 528What: /sys/bus/usb/devices/usbX/ep_<N>/bmAttributes 529Description: 530 Attributes which apply to the endpoint as described on its 531 descriptor, in hexadecimal. The endpoint type on this 532 bitmapped field is also shown at: 533 534 /sys/bus/usb/devices/usbX/ep_<N>/type 535 536 See USB specs for its meaning. 537 538What: /sys/bus/usb/devices/usbX/ep_<N>/direction 539Description: 540 Direction of the endpoint. Can be: 541 542 - both (on control endpoints) 543 - in 544 - out 545 546What: /sys/bus/usb/devices/usbX/ep_<N>/interval 547Description: 548 Interval for polling endpoint for data transfers, in 549 milisseconds or microseconds. 550 551What: /sys/bus/usb/devices/usbX/ep_<N>/type 552Description: 553 Descriptor type. Can be: 554 555 - Control 556 - Isoc 557 - Bulk 558 - Interrupt 559 - unknown 560 561What: /sys/bus/usb/devices/usbX/ep_<N>/wMaxPacketSize 562Description: 563 Maximum packet size this endpoint is capable of 564 sending or receiving, in hexadecimal. 565