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