diff options
Diffstat (limited to 'Documentation/admin-guide/thunderbolt.rst')
| -rw-r--r-- | Documentation/admin-guide/thunderbolt.rst | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/Documentation/admin-guide/thunderbolt.rst b/Documentation/admin-guide/thunderbolt.rst index 613cb24c76c7..0d4348445f91 100644 --- a/Documentation/admin-guide/thunderbolt.rst +++ b/Documentation/admin-guide/thunderbolt.rst @@ -153,6 +153,22 @@ If the user still wants to connect the device they can either approve the device without a key or write a new key and write 1 to the ``authorized`` file to get the new key stored on the device NVM. +De-authorizing devices +---------------------- +It is possible to de-authorize devices by writing ``0`` to their +``authorized`` attribute. This requires support from the connection +manager implementation and can be checked by reading domain +``deauthorization`` attribute. If it reads ``1`` then the feature is +supported. + +When a device is de-authorized the PCIe tunnel from the parent device +PCIe downstream (or root) port to the device PCIe upstream port is torn +down. This is essentially the same thing as PCIe hot-remove and the PCIe +toplogy in question will not be accessible anymore until the device is +authorized again. If there is storage such as NVMe or similar involved, +there is a risk for data loss if the filesystem on that storage is not +properly shut down. You have been warned! + DMA protection utilizing IOMMU ------------------------------ Recent systems from 2018 and forward with Thunderbolt ports may natively |