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/.../<hub_interface>/port<X>/connector 248Date: December 2021 249Contact: Heikki Krogerus <heikki.krogerus@linux.intel.com> 250Description: 251 Link to the USB Type-C connector when available. This link is 252 only created when USB Type-C Connector Class is enabled, and 253 only if the system firmware is capable of describing the 254 connection between a port and its connector. 255 256What: /sys/bus/usb/devices/.../<hub_interface>/port<X>/disable 257Date: June 2022 258Contact: Michael Grzeschik <m.grzeschik@pengutronix.de> 259Description: 260 This file controls the state of a USB port, including 261 Vbus power output (but only on hubs that support 262 power switching -- most hubs don't support it). If 263 a port is disabled, the port is unusable: Devices 264 attached to the port will not be detected, initialized, 265 or enumerated. 266 267What: /sys/bus/usb/devices/.../power/usb2_lpm_l1_timeout 268Date: May 2013 269Contact: Mathias Nyman <mathias.nyman@linux.intel.com> 270Description: 271 USB 2.0 devices may support hardware link power management (LPM) 272 L1 sleep state. The usb2_lpm_l1_timeout attribute allows 273 tuning the timeout for L1 inactivity timer (LPM timer), e.g. 274 needed inactivity time before host requests the device to go to L1 sleep. 275 Useful for power management tuning. 276 Supported values are 0 - 65535 microseconds. 277 278What: /sys/bus/usb/devices/.../power/usb2_lpm_besl 279Date: May 2013 280Contact: Mathias Nyman <mathias.nyman@linux.intel.com> 281Description: 282 USB 2.0 devices that support hardware link power management (LPM) 283 L1 sleep state now use a best effort service latency value (BESL) to 284 indicate the best effort to resumption of service to the device after the 285 initiation of the resume event. 286 If the device does not have a preferred besl value then the host can select 287 one instead. This usb2_lpm_besl attribute allows to tune the host selected besl 288 value in order to tune power saving and service latency. 289 290 Supported values are 0 - 15. 291 More information on how besl values map to microseconds can be found in 292 USB 2.0 ECN Errata for Link Power Management, section 4.10) 293 294What: /sys/bus/usb/devices/.../rx_lanes 295Date: March 2018 296Contact: Mathias Nyman <mathias.nyman@linux.intel.com> 297Description: 298 Number of rx lanes the device is using. 299 USB 3.2 adds Dual-lane support, 2 rx and 2 tx lanes over Type-C. 300 Inter-Chip SSIC devices support asymmetric lanes up to 4 lanes per 301 direction. Devices before USB 3.2 are single lane (rx_lanes = 1) 302 303What: /sys/bus/usb/devices/.../tx_lanes 304Date: March 2018 305Contact: Mathias Nyman <mathias.nyman@linux.intel.com> 306Description: 307 Number of tx lanes the device is using. 308 USB 3.2 adds Dual-lane support, 2 rx and 2 tx -lanes over Type-C. 309 Inter-Chip SSIC devices support asymmetric lanes up to 4 lanes per 310 direction. Devices before USB 3.2 are single lane (tx_lanes = 1) 311 312What: /sys/bus/usb/devices/usbX/bAlternateSetting 313Description: 314 The current interface alternate setting number, in decimal. 315 316 See USB specs for its meaning. 317 318What: /sys/bus/usb/devices/usbX/bcdDevice 319Description: 320 The device's release number, in hexadecimal. 321 322 See USB specs for its meaning. 323 324What: /sys/bus/usb/devices/usbX/bConfigurationValue 325Description: 326 While a USB device typically have just one configuration 327 setting, some devices support multiple configurations. 328 329 This value shows the current configuration, in decimal. 330 331 Changing its value will change the device's configuration 332 to another setting. 333 334 The number of configurations supported by a device is at: 335 336 /sys/bus/usb/devices/usbX/bNumConfigurations 337 338 See USB specs for its meaning. 339 340What: /sys/bus/usb/devices/usbX/bDeviceClass 341Description: 342 Class code of the device, in hexadecimal. 343 344 See USB specs for its meaning. 345 346What: /sys/bus/usb/devices/usbX/bDeviceProtocol 347Description: 348 Protocol code of the device, in hexadecimal. 349 350 See USB specs for its meaning. 351 352What: /sys/bus/usb/devices/usbX/bDeviceSubClass 353Description: 354 Subclass code of the device, in hexadecimal. 355 356 See USB specs for its meaning. 357 358What: /sys/bus/usb/devices/usbX/bInterfaceClass 359Description: 360 Class code of the interface, in hexadecimal. 361 362 See USB specs for its meaning. 363 364What: /sys/bus/usb/devices/usbX/bInterfaceNumber 365Description: 366 Interface number, in hexadecimal. 367 368 See USB specs for its meaning. 369 370What: /sys/bus/usb/devices/usbX/bInterfaceProtocol 371Description: 372 Protocol code of the interface, in hexadecimal. 373 374 See USB specs for its meaning. 375 376What: /sys/bus/usb/devices/usbX/bInterfaceSubClass 377Description: 378 Subclass code of the interface, in hexadecimal. 379 380 See USB specs for its meaning. 381 382What: /sys/bus/usb/devices/usbX/bmAttributes 383Description: 384 Attributes of the current configuration, in hexadecimal. 385 386 See USB specs for its meaning. 387 388What: /sys/bus/usb/devices/usbX/bMaxPacketSize0 389Description: 390 Maximum endpoint 0 packet size, in decimal. 391 392 See USB specs for its meaning. 393 394What: /sys/bus/usb/devices/usbX/bMaxPower 395Description: 396 Maximum power consumption of the active configuration of 397 the device, in miliamperes. 398 399What: /sys/bus/usb/devices/usbX/bNumConfigurations 400Description: 401 Number of the possible configurations of the device, in 402 decimal. The current configuration is controlled via: 403 404 /sys/bus/usb/devices/usbX/bConfigurationValue 405 406 See USB specs for its meaning. 407 408What: /sys/bus/usb/devices/usbX/bNumEndpoints 409Description: 410 Number of endpoints used on this interface, in hexadecimal. 411 412 See USB specs for its meaning. 413 414What: /sys/bus/usb/devices/usbX/bNumInterfaces 415Description: 416 Number of interfaces on this device, in decimal. 417 418What: /sys/bus/usb/devices/usbX/busnum 419Description: 420 Number of the bus. 421 422What: /sys/bus/usb/devices/usbX/configuration 423Description: 424 Contents of the string descriptor associated with the 425 current configuration. It may include the firmware version 426 of a device and/or its serial number. 427 428What: /sys/bus/usb/devices/usbX/descriptors 429Description: 430 Contains the interface descriptors, in binary. 431 432What: /sys/bus/usb/devices/usbX/idProduct 433Description: 434 Product ID, in hexadecimal. 435 436What: /sys/bus/usb/devices/usbX/idVendor 437Description: 438 Vendor ID, in hexadecimal. 439 440What: /sys/bus/usb/devices/usbX/devspec 441Description: 442 Displays the Device Tree Open Firmware node of the interface. 443 444What: /sys/bus/usb/devices/usbX/avoid_reset_quirk 445Description: 446 Most devices have this set to zero. 447 448 If the value is 1, enable a USB quirk that prevents this 449 device to use reset. 450 451 (read/write) 452 453What: /sys/bus/usb/devices/usbX/devnum 454Description: 455 USB interface device number, in decimal. 456 457What: /sys/bus/usb/devices/usbX/devpath 458Description: 459 String containing the USB interface device path. 460 461What: /sys/bus/usb/devices/usbX/manufacturer 462Description: 463 Vendor specific string containing the name of the 464 manufacturer of the device. 465 466What: /sys/bus/usb/devices/usbX/maxchild 467Description: 468 Number of ports of an USB hub 469 470What: /sys/bus/usb/devices/usbX/persist 471Description: 472 Keeps the device even if it gets disconnected. 473 474What: /sys/bus/usb/devices/usbX/product 475Description: 476 Vendor specific string containing the name of the 477 device's product. 478 479What: /sys/bus/usb/devices/usbX/speed 480Description: 481 Shows the device's max speed, according to the USB version, 482 in Mbps. 483 Can be: 484 485 ======= ==================== 486 Unknown speed unknown 487 1.5 Low speed 488 15 Full speed 489 480 High Speed 490 5000 Super Speed 491 10000 Super Speed+ 492 20000 Super Speed+ Gen 2x2 493 ======= ==================== 494 495What: /sys/bus/usb/devices/usbX/supports_autosuspend 496Description: 497 Returns 1 if the device doesn't support autosuspend. 498 Otherwise, returns 0. 499 500What: /sys/bus/usb/devices/usbX/urbnum 501Description: 502 Number of URBs submitted for the whole device. 503 504What: /sys/bus/usb/devices/usbX/version 505Description: 506 String containing the USB device version, as encoded 507 at the BCD descriptor. 508 509What: /sys/bus/usb/devices/usbX/power/autosuspend 510Description: 511 Time in milliseconds for the device to autosuspend. If the 512 value is negative, then autosuspend is prevented. 513 514 (read/write) 515 516What: /sys/bus/usb/devices/usbX/power/active_duration 517Description: 518 The total time the device has not been suspended. 519 520What: /sys/bus/usb/devices/usbX/power/connected_duration 521Description: 522 The total time (in msec) that the device has been connected. 523 524What: /sys/bus/usb/devices/usbX/power/level 525Description: 526 527What: /sys/bus/usb/devices/usbX/ep_<N>/bEndpointAddress 528Description: 529 The address of the endpoint described by this descriptor, 530 in hexadecimal. The endpoint direction on this bitmapped field 531 is also shown at: 532 533 /sys/bus/usb/devices/usbX/ep_<N>/direction 534 535 See USB specs for its meaning. 536 537What: /sys/bus/usb/devices/usbX/ep_<N>/bInterval 538Description: 539 The interval of the endpoint as described on its descriptor, 540 in hexadecimal. The actual interval depends on the version 541 of the USB. Also shown in time units at 542 /sys/bus/usb/devices/usbX/ep_<N>/interval. 543 544What: /sys/bus/usb/devices/usbX/ep_<N>/bLength 545Description: 546 Number of bytes of the endpoint descriptor, in hexadecimal. 547 548What: /sys/bus/usb/devices/usbX/ep_<N>/bmAttributes 549Description: 550 Attributes which apply to the endpoint as described on its 551 descriptor, in hexadecimal. The endpoint type on this 552 bitmapped field is also shown at: 553 554 /sys/bus/usb/devices/usbX/ep_<N>/type 555 556 See USB specs for its meaning. 557 558What: /sys/bus/usb/devices/usbX/ep_<N>/direction 559Description: 560 Direction of the endpoint. Can be: 561 562 - both (on control endpoints) 563 - in 564 - out 565 566What: /sys/bus/usb/devices/usbX/ep_<N>/interval 567Description: 568 Interval for polling endpoint for data transfers, in 569 milisseconds or microseconds. 570 571What: /sys/bus/usb/devices/usbX/ep_<N>/type 572Description: 573 Descriptor type. Can be: 574 575 - Control 576 - Isoc 577 - Bulk 578 - Interrupt 579 - unknown 580 581What: /sys/bus/usb/devices/usbX/ep_<N>/wMaxPacketSize 582Description: 583 Maximum packet size this endpoint is capable of 584 sending or receiving, in hexadecimal. 585