AMD DisplayPort Thunderbolt Tunneling driver already available in latest Linux kernel patches, USB4 support finally coming in early 2022
Even though AMD’s Ryzen 5000 processors are overall better than Intel’s current Rocket Lake solutions, the lack of Thunderbolt support from Team Red is making it tough for some users to switch sides. We know Thunderbolt is not an Intel-exclusive anymore, especially now that the standard is merged with USB4, so AMD should finally introduce Thunderbolt support very soon. Previous leaks were suggesting that this could happen with the launch of the Ryzen Embedded V3000 series and the Ryzen 6000H laptop APUs in early 2022, but now we are seeing an indirect confirmation straight from AMD hidden in the latest Linux kernel patches.
Phoronix reports that the latest AMD GPU kernel graphics driver for Linux includes mentions of USB4 DisplayPort tunneling. This is a new feature specific to the USB4 standard that ties directly to the Thunderbolt 3 standard. It allows multiple protocols like USB, DisplayPort and PCIe to operate at the same time, although with restricted bandwidth. USB4 also supports alt modes that target the full bandwidth at a specific protocol. For instance, the DisplayPort 2.0 protocol supported now by USB4 can use up to 80 Gbps bandwidth to enable 8K resolutions at 60 Hz with HDR10 color gamut. However, the AMD Linux driver currently only supports DisplayPort 1.4 tunneling through Thunderbolt 3, which limits the available bandwidth to well under 40 Gbps, yet this solution may still be helpful when using a USB dock.
AMD’s USB4 DP tunneling drivers may be added to the 5.16 version of Linux releasing by the end of this year. It might take a little longer, but the near-finalized code that is already available could only mean that USB4 support is coming to AMD’s platforms in early 2022.