Re: [PATCH 2/2] samples: rust: add a USB driver sample

["Danilo Krummrich" <dakr@kernel.org>]

On Sat Sep 6, 2025 at 4:50 PM CEST, Daniel Almeida wrote:
> So far I see a pattern where sample drivers count as users. This has been the
> case, for example, for rust_dma.rs. I was under the impression that the same
> would apply here. Although I do realize that there were plans for dma code
> other than rust_dma.rs, of course.

This isn't the case, we have those sample drivers to make it easy to review the
the code and illustrate in an isolated context how it works. But, there has
always been a "real" user behind that. In the case of the DMA work it was Nova.

> As for Nova and Tyr, these are projects with a lot of big companies involved.
>
> They were able to break this chicken and egg situation in part due to that,
> because companies were willing to allocate engineers for both the drivers _and_
> the required infrastructure. Unless the same can be said for USB, media or any
> other subsystems, I don't see it happening.

Well, this is true for Nova and Tyr, but I disagree that this is the reason we
were able to break the chicken and egg problem.

For instance, the initial lift around the driver core, PCI, I/O, etc.
infrastructure was done by me, a single person. This could have been happening
in the context of a very simple and small driver as well, rather than a big GPU
driver with lots of companies and people involved.

Igor (Cc) is doing the initial lift for I2C and Michal (Cc) for PWM for
instance.

So, I see those things happen and I don't think that such initial lifting
necessarily needs big companies with dozens of engineers being involved.

If we know people who want to write drivers for a subsystem that doesn't yet
have Rust infrastructure (such as USB), let's encourage them to get started /
involved anyways and let's help them as they go.

But also please don't get me wrong, I understand and very much appreciate you
want to get the ball rolling, but let's not discourage people by making it
sounds as if it would be impossible for individuals.