1What: /sys/bus/pci/drivers/xhci_hcd/.../dbc 2Date: June 2017 3Contact: Lu Baolu <baolu.lu@linux.intel.com> 4Description: 5 xHCI compatible USB host controllers (i.e. super-speed 6 USB3 controllers) are often implemented with the Debug 7 Capability (DbC). It can present a debug device which 8 is fully compliant with the USB framework and provides 9 the equivalent of a very high performance full-duplex 10 serial link for debug purpose. 11 12 The DbC debug device shares a root port with xHCI host. 13 When the DbC is enabled, the root port will be assigned 14 to the Debug Capability. Otherwise, it will be assigned 15 to xHCI. 16 17 Writing "enable" to this attribute will enable the DbC 18 functionality and the shared root port will be assigned 19 to the DbC device. Writing "disable" to this attribute 20 will disable the DbC functionality and the shared root 21 port will roll back to the xHCI. 22 23 Reading this attribute gives the state of the DbC. It 24 can be one of the following states: disabled, enabled, 25 initialized, connected, configured and stalled. 26