An official release of the USB 4 specifications was made in June. USB 4.0 allows two-track operation on existing USB Type C cables and up to 40 Gbps on certified cables while maintaining compatibility with USB3/USB2 and Thunderbolt 3.
USB 4 offers up to 40 Gbps similar to Thunderbolt 3
There were 22 first patches on the Linux kernel mailing list that provided basic support for USB 4.0. USB 4 support in its current form consists of less than four thousand lines of new code in the kernel. The boot process is not too dramatic as USB4 is based on Thunderbolt and therefore reuses the existing Thunderbolt driver code in the kernel.
As we approach the release of USB 4, which will have speeds similar to Thunderbolt 3 (40 Gbps), PCIe compatibility and DisplayPort within the USB-C form factor, there are already drivers that support the new standard and ensure that the release and transition to the latest USB version run smoothly.
Intel’s open-source engineers have submitted their first patches for USB 4.0 support for the Linux kernel
With this initial support for the Linux kernel, there is still no support for USB 4.0 power management as one of the key elements to be implemented in the short term. But features like PCIe tunneling, DisplayPort tunneling, USB 3.x tunneling. P2P networks, firmware updates, and other basics are already available.
At the moment the support is in the pull request phase, so it should be integrated very soon, most likely with the Linux kernel version 5.5, when other features like power management will be completed soon.
The new USB 4 standard is getting closer and closer and offers great advantages in terms of data transfer speed.
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