PreSonus Quantum 2626 is a 26-input, 26-output rackmount Thunderbolt audio interface focused on delivering ultra-low latency. It's advertised as among the fastest audio interfaces available. On the downside, it's expensive by enthusiast/hobbyist standards at around $700 USD.
A "Quantum" Linux sound driver was proposed today for upstream kernel review in providing this independently-developed audio driver successfully tested on the Quantum 2626 though other devices may end up being supported in the future.
Nicholas Johnson explained in the RFC patch announcement:
"This RFC series adds an ALSA PCI driver for PreSonus Quantum PCIe/Thunderbolt audio interfaces.
This project is independent and is not affiliated with PreSonus or Fender.
The driver provides playback, capture, raw MIDI, sample-rate control, clock-source control, XRUN reporting, and surprise-removal handling. It targets the Quantum PCI family and currently has verified support for the Quantum 2626.
The implementation keeps the hardware path direct and multichannel, with the aim of being small, reviewable, and suitable for eventual upstreaming.
I want to thank my best friend, Ju Ern, for lending me the machine used to develop the driver, and the Asahi Linux project for m1n1 and the tooling that made the hardware tracing and analysis possible.
Only the verified 2626 device ID is matched by the driver at present.
I am sending this as RFC to gather review and testing before asking for merge. I would especially appreciate feedback on ALSA integration, device enumeration, runtime PM/latency handling, and upstream expectations for the driver."
It's now awaiting review feedback on its hopeful path for eventually being upstreamed to the mainline Linux kernel.