Link Layer Validation Device is a standard device for testing of Super Speed Link Layer tests. These nodes are available in sysfs only when lvs driver is bound with root hub device. What: /sys/bus/usb/devices/.../get_dev_desc Date: March 2014 Contact: Pratyush Anand Description: Write to this node to issue "Get Device Descriptor" for Link Layer Validation device. It is needed for TD.7.06. What: /sys/bus/usb/devices/.../u1_timeout Date: March 2014 Contact: Pratyush Anand Description: Set "U1 timeout" for the downstream port where Link Layer Validation device is connected. Timeout value must be between 0 and 127. It is needed for TD.7.18, TD.7.19, TD.7.20 and TD.7.21. What: /sys/bus/usb/devices/.../u2_timeout Date: March 2014 Contact: Pratyush Anand Description: Set "U2 timeout" for the downstream port where Link Layer Validation device is connected. Timeout value must be between 0 and 127. It is needed for TD.7.18, TD.7.19, TD.7.20 and TD.7.21. What: /sys/bus/usb/devices/.../hot_reset Date: March 2014 Contact: Pratyush Anand Description: Write to this node to issue "Reset" for Link Layer Validation device. It is needed for TD.7.29, TD.7.31, TD.7.34 and TD.7.35. What: /sys/bus/usb/devices/.../u3_entry Date: March 2014 Contact: Pratyush Anand Description: Write to this node to issue "U3 entry" for Link Layer Validation device. It is needed for TD.7.35 and TD.7.36. What: /sys/bus/usb/devices/.../u3_exit Date: March 2014 Contact: Pratyush Anand Description: Write to this node to issue "U3 exit" for Link Layer Validation device. It is needed for TD.7.36. What: /sys/bus/usb/devices/.../enable_compliance Date: July 2017 Description: Write to this node to set the port to compliance mode to test with Link Layer Validation device. It is needed for TD.7.34. What: /sys/bus/usb/devices/.../warm_reset Date: July 2017 Description: Write to this node to issue "Warm Reset" for Link Layer Validation device. It may be needed to properly reset an xHCI 1.1 host port if compliance mode needed to be explicitly enabled.