| 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. |
