This allows the PCI topology to change, but assumes that thunderbolt host controllers
are enumerated in the same order every time.
It won't matter if the first controller jumped from bus 5 to 7 and consequently the
second from 65 to 71, but rather that the first was enumerated followed by the second.
Systems with multiple host controllers will most likely have a different
NVM image for each controller but there is no guarantee that the device_id
within the NVM image varies from one controller to another.
To account for this, build a GUID that contains the last element of the
Thunderbolt controller's udev path.
Sample GUID strings from an XPS 9380 (which only contains one host controller):
```
Guid: 0f401ed2-b847-532a-adc8-3193fc737be6 <- TBT-00d408af-native
Guid: 420b0596-f5cb-5fd7-8416-c99d48ad8de9 <- TBT-00d408af-native-0000:05:00.0
```
This commit follows the presumption that the kernel will enumerate the controllers
in the same order every time.
Kernel v4.15 added support for native enumeration of Thunderbolt
topology. The enumeration mode affects both the BIOS and TBT FW
operation so they must agree on it. Platforms may support both modes,
native and "legacy" (or "BIOS-assist").
This change makes sure the new image is compatible with the current
controller mode (otherwise the BIOS and TBT FW will not be alligned on
it at least until next boot) and also adds a new GUID generation logic
for a controller in "native" mode so LVFS could contain 2 images, one for
the "legacy" mode and one for "native".
Signed-off-by: Yehezkel Bernat <yehezkel.bernat@intel.com>
* Minor changes in Thunderbolt README file
* Remove PCI-oriented GUID
* Handle Thunderbolt controller in safe-mode
* Get progress status updates for Thunderbolt
* Fix for Thunderbolt FW version display
* Style changes from pull request review
