0001 What: /sys/bus/pci/drivers/xhci_hcd/.../dbc
0002 Date: June 2017
0003 Contact: Lu Baolu <baolu.lu@linux.intel.com>
0004 Description:
0005 xHCI compatible USB host controllers (i.e. super-speed
0006 USB3 controllers) are often implemented with the Debug
0007 Capability (DbC). It can present a debug device which
0008 is fully compliant with the USB framework and provides
0009 the equivalent of a very high performance full-duplex
0010 serial link for debug purpose.
0011
0012 The DbC debug device shares a root port with xHCI host.
0013 When the DbC is enabled, the root port will be assigned
0014 to the Debug Capability. Otherwise, it will be assigned
0015 to xHCI.
0016
0017 Writing "enable" to this attribute will enable the DbC
0018 functionality and the shared root port will be assigned
0019 to the DbC device. Writing "disable" to this attribute
0020 will disable the DbC functionality and the shared root
0021 port will roll back to the xHCI.
0022
0023 Reading this attribute gives the state of the DbC. It
0024 can be one of the following states: disabled, enabled,
0025 initialized, connected, configured and stalled.
