Update the Thunderbolt documentation to explain how to use the ``switch_nvm_vendor_override`` parameter to be able to reflash a Thunderbolt controller's NVM reporting an invalid Vendor ID. Signed-off-by: Francisco Blas Izquierdo Riera (klondike) <klondike@xxxxxxxxxxx> --- Documentation/admin-guide/thunderbolt.rst | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/Documentation/admin-guide/thunderbolt.rst b/Documentation/admin-guide/thunderbolt.rst index 2ed79f41a4..15c8c73331 100644 --- a/Documentation/admin-guide/thunderbolt.rst +++ b/Documentation/admin-guide/thunderbolt.rst @@ -296,6 +296,16 @@ 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. +When the NVM image is corrupted, certain host controllers will report +an invalid Vendor ID preventing the module from exposing the nvm access +nodes. If so, either load the thunderbolt module with option +``switch_nvm_vendor_override=vendorID`` or add +``thunderbolt.switch_nvm_vendor_override=vendorID`` to your boot +parameters. You need to set ``vendorID`` to the appropriate value. +On Intel systems, this is likely ``0x8086`` but you should verify this +before doing anything as otherwise you may cause further damage to your +controller. + Networking over Thunderbolt cable --------------------------------- Thunderbolt technology allows software communication between two hosts
