AMD has made tweaks to USB 4 handling in Linux, which come on top of recent patches to ensure that USB 4 works with laptops powered by Ryzen 6000 mobile silicon.
As you may recall, laptops with Ryzen 6000 APUs inside – otherwise known as ‘Rembrandt’ chips – are the first to support USB 4 (and therefore Thunderbolt 3, optionally) on the AMD front, with Team Red now pushing to get the software side ready for when these devices launch, and they should arrive imminently (the company has previously said Ryzen 6000 notebooks will be out at some point in February, or the first models should be, anyway).
Hence the Linux patches which work on USB 4 handling improvements, as spotted by Phoronix.com.
As you may be aware, USB 4 is based on Intel’s Thunderbolt 3 tech, with the main difference being that it offers blazing-fast 40Gbps speeds without having to work directly with Intel to implement it (and pay royalties, of course). While USB 4 is backwards compatible with Thunderbolt 3, device makers must make an active decision to support the latter (it’s optional as to whether they do, or not).
Specifically, the latest patches for Linux witness changes to the “is_thunderbolt” check to alter what happens for a device that’s connected by Thunderbolt, rather than directly via PCIe, and to determine if said device is external (and removable).
This comes on top of AMD’s previous work on DisplayPort Tunneling and more (the fresh patching, by the way, was documented by Mario Limonciello, Principal Member of Technical Staff and a Linux expert at AMD).
Analysis: Powering up Linux laptops, including with external GPUs
You don’t really need to know all the technical ins-and-outs here, as it’s pretty complex stuff, but the gist of it is that AMD is pushing forward to prepare the ground for USB 4 to work correctly in Linux, just as the Ryzen 6000 laptops we mentioned at the outset are set to be sprung on the world. (These Ryzen 6000-powered notebooks also introduce PCIe 4.0 and DDR5 support, among other fresh tech advances).
A USB 4 connection allows for data transfer, monitor signals, power delivery (100W), and it’s fast enough to use for hooking up an external GPU to your laptop, to really beef up graphics power when at your desk. It’s worth noting that the aforementioned Linux patches also clean up AMD driver code for working with external GPUs (and also for Nouveau, the open source driver for Nvidia graphics cards under Linux).
