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+What: /sys/bus/pci/drivers/xhci_hcd/.../dbc
+Date: June 2017
+Contact: Lu Baolu <baolu.lu@linux.intel.com>
+Description:
+ xHCI compatible USB host controllers (i.e. super-speed
+ USB3 controllers) are often implemented with the Debug
+ Capability (DbC). It can present a debug device which
+ is fully compliant with the USB framework and provides
+ the equivalent of a very high performance full-duplex
+ serial link for debug purpose.
+
+ The DbC debug device shares a root port with xHCI host.
+ When the DbC is enabled, the root port will be assigned
+ to the Debug Capability. Otherwise, it will be assigned
+ to xHCI.
+
+ Writing "enable" to this attribute will enable the DbC
+ functionality and the shared root port will be assigned
+ to the DbC device. Writing "disable" to this attribute
+ will disable the DbC functionality and the shared root
+ port will roll back to the xHCI.
+
+ Reading this attribute gives the state of the DbC. It
+ can be one of the following states: disabled, enabled,
+ initialized, connected, configured and stalled.
+
+What: /sys/bus/pci/drivers/xhci_hcd/.../dbc_idVendor
+Date: March 2023
+Contact: Mathias Nyman <mathias.nyman@linux.intel.com>
+Description:
+ This dbc_idVendor attribute lets us change the idVendor field
+ presented in the USB device descriptor by this xhci debug
+ device.
+ Value can only be changed while debug capability (DbC) is in
+ disabled state to prevent USB device descriptor change while
+ connected to a USB host.
+ The default value is 0x1d6b (Linux Foundation).
+ It can be any 16-bit integer.
+
+What: /sys/bus/pci/drivers/xhci_hcd/.../dbc_idProduct
+Date: March 2023
+Contact: Mathias Nyman <mathias.nyman@linux.intel.com>
+Description:
+ This dbc_idProduct attribute lets us change the idProduct field
+ presented in the USB device descriptor by this xhci debug
+ device.
+ Value can only be changed while debug capability (DbC) is in
+ disabled state to prevent USB device descriptor change while
+ connected to a USB host.
+ The default value is 0x0010. It can be any 16-bit integer.
+
+What: /sys/bus/pci/drivers/xhci_hcd/.../dbc_bcdDevice
+Date: March 2023
+Contact: Mathias Nyman <mathias.nyman@linux.intel.com>
+Description:
+ This dbc_bcdDevice attribute lets us change the bcdDevice field
+ presented in the USB device descriptor by this xhci debug
+ device.
+ Value can only be changed while debug capability (DbC) is in
+ disabled state to prevent USB device descriptor change while
+ connected to a USB host.
+ The default value is 0x0010. (device rev 0.10)
+ It can be any 16-bit integer.
+
+What: /sys/bus/pci/drivers/xhci_hcd/.../dbc_bInterfaceProtocol
+Date: March 2023
+Contact: Mathias Nyman <mathias.nyman@linux.intel.com>
+Description:
+ This attribute lets us change the bInterfaceProtocol field
+ presented in the USB Interface descriptor by the xhci debug
+ device.
+ Value can only be changed while debug capability (DbC) is in
+ disabled state to prevent USB descriptor change while
+ connected to a USB host.
+ The default value is 1 (GNU Remote Debug command).
+ Other permissible value is 0 which is for vendor defined debug
+ target.