Duncan Laurie has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/44919 )
Change subject: mb/google/volteer: Enable USB4 retimer driver ......................................................................
Patch Set 4:
(1 comment)
https://review.coreboot.org/c/coreboot/+/44919/4/src/mainboard/google/voltee... File src/mainboard/google/volteer/variants/baseboard/devicetree.cb:
https://review.coreboot.org/c/coreboot/+/44919/4/src/mainboard/google/voltee... PS4, Line 395: drivers/intel/usb4/retimer
Just curious: Is this retimer used on all variants?
The retimer is required for any that have usb4 so the probe statements should enable/disable it properly. we're using DB_USB because that is what volteer had, but it can be on the MLB (like voxel) where it still sets DB_USB=USB4_GEN3 at least.
All the usb4 designs also seem to stick to GPP_H10 for power control, even if it has multiple retimers, although that could in theory change in a future design.