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Diffstat (limited to 'Documentation/admin-guide/thunderbolt.rst')
| -rw-r--r-- | Documentation/admin-guide/thunderbolt.rst | 42 |
1 files changed, 35 insertions, 7 deletions
diff --git a/Documentation/admin-guide/thunderbolt.rst b/Documentation/admin-guide/thunderbolt.rst index d0502691dfa1..102c693c8f81 100644 --- a/Documentation/admin-guide/thunderbolt.rst +++ b/Documentation/admin-guide/thunderbolt.rst @@ -296,6 +296,39 @@ information is missing. To recover from this mode, one needs to flash a valid NVM image to the host controller in the same way it is done in the previous chapter. +Tunneling events +---------------- +The driver sends ``KOBJ_CHANGE`` events to userspace when there is a +tunneling change in the ``thunderbolt_domain``. The notification carries +following environment variables:: + + TUNNEL_EVENT=<EVENT> + TUNNEL_DETAILS=0:12 <-> 1:20 (USB3) + +Possible values for ``<EVENT>`` are: + + activated + The tunnel was activated (created). + + changed + There is a change in this tunnel. For example bandwidth allocation was + changed. + + deactivated + The tunnel was torn down. + + low bandwidth + The tunnel is not getting optimal bandwidth. + + insufficient bandwidth + There is not enough bandwidth for the current tunnel requirements. + +The ``TUNNEL_DETAILS`` is only provided if the tunnel is known. For +example, in case of Firmware Connection Manager this is missing or does +not provide full tunnel information. In case of Software Connection Manager +this includes full tunnel details. The format currently matches what the +driver uses when logging. This may change over time. + Networking over Thunderbolt cable --------------------------------- Thunderbolt technology allows software communication between two hosts @@ -325,12 +358,7 @@ Forcing power Many OEMs include a method that can be used to force the power of a Thunderbolt controller to an "On" state even if nothing is connected. If supported by your machine this will be exposed by the WMI bus with -a sysfs attribute called "force_power". - -For example the intel-wmi-thunderbolt driver exposes this attribute in: - /sys/bus/wmi/devices/86CCFD48-205E-4A77-9C48-2021CBEDE341/force_power - - To force the power to on, write 1 to this attribute file. - To disable force power, write 0 to this attribute file. +a sysfs attribute called "force_power", see +Documentation/ABI/testing/sysfs-platform-intel-wmi-thunderbolt for details. Note: it's currently not possible to query the force power state of a platform. |