tbt: Support Barlow Ridge
Barlow Ridge does not support Firmware Connection Manager (FCM/FWCM). Add support for and use Software Connection Manager (SCM/SWCM).
Barlow Ridge BIOS Implementation Guide r0.9 (#782921) has the following notes:
- 4 USBC Configuration Requirements
- 4.3.1 Overview
In addition, BR only supports SW CM due to the hardware constraint (no arc. logic design)
- 5 USB4 Software Connection Manager
- 5.1.3.1 BIOS and TBT FW Handshake
Barlow Ridge TBT FW does not support FW CM mode.
- coreboot
- Select
SOFTWARE_CONNECTION_MANAGERfor boards usingSOC_INTEL_ENABLE_USB4_PCIE_RESOURCES - Update dTBT driver to support SCM
- Update dTBT driver to support Barlow Ridge
- Select
- linux
- Revert https://github.com/pop-os/linux/commit/0470d838a84556865d4adcdc4ad84ac3e489ef6d
Barlow Ridge BIOS Implementation Guide r1.1 (2024-07-16) now states that FW CM is supported.
- 5 USB4 Software Connection Manager
The CM in the USB4 host system can be firmware base connection manager (FW CM) just like Thunderbolt 3 generation to support any BIOS or OS that doesn’t support USB4 software connection manager (SW CM) for backward compatible; or can be SW CM base when BIOS or OS support that feature.
But attempting to use the commands to enable FW CM timeout.