Rust-only means that there is no alternative C driver, and that the bulk of the logic (not the calls to kernel-wide abstractions) is implemented in Rust. Only the mainline release from kernel.org is considered.
6.8 introduced a driver for https://www.asix.com.tw/en/product/EmbeddedEthernet/1-Port_Ethernet/AX88796B , but it's not consumer-grade hardware and the Rust driver is a duplicate of the C driver.
6.12 introduced a driver for https://www.macom.com/products/product-detail/QT2025, not consumer-grade and duplicates the C driver. There's also a Rust-only QR code panic message "driver", but it isn't tied to actual hardware.
6.15 introduced the "Nova" driver for nvidia graphics, which fits the Rust-only and consumer-grade criteria, but isn't a full usable driver yet.
6.18 adds the "Tyr" driver for Mali GPUs (duplicates the existing C, and not yet fully functional), a Binder driver (not a real device), and an example USB driver. Work on Nova continues.
1,000
3.00Android's 6.12 kernel is shipping with ashmem which I believe (?) has no C alternative.
Being specifically in an Android kernel release would rather confuse the result of this question. Maybe it should be rephrased to specify upstream releases?
Anyway similar to the QR code thing, this driver is intended for use on consumer hardware but it's not actually a driver "for" that hardware.
Edit: I think I misunderstood, this is just a reimplementation of a C thing, like Binder. I'll double check later today when I get to a proper computer.
Edit2: yep I did indeed misunderstand
@BrendanJackman To make this question more clear-cut, I'm only considering the mainline release, linked from the kernel.org homepage. If we were considering vendor kernels, the Asahi kernel and possibly a few less well-know ones would have qualified a while ago.
It seems 6.16 has https://rust-for-linux.com/nova-gpu-driver but it's intended to (eventually) supersede the existing (C) nouveau driver so fails on the "there is no alternative C driver" for the same hardware.
@MikeLinksvayer Nova targets newer GPUs that have not been released yet. It's not clear yet what the hardware support overlap will be between the Rust and C drivers.
https://www.phoronix.com/news/Torvalds-On-Rust-Maintainers this and the below message from Torvalds' lieutenant bear directly on which release will have the first Rust-only driver for consumer-grade hardware, but seems to me they at least make "never" extremely unlikely, and probably push things up a bit.
An OpenGL 4.6-compliant driver for Apple M* GPUs exists out-of-tree. The author has this to say about it being mainlined:
> At the rate things are going, I wouldn't be surprised if upstreaming the drm/asahi driver isn't possible until 2026 at the earliest.
@Jono3h If the use of Rust in the kernel gets deprecated before any consumer-grade driver makes it in. Highly unlikely, but felt correct to add it.
If this resolves to a kernel version not yet listed, I'll add new vote entries. I'll also extend the resolution deadline as needed.