Great to see progress on mainlining more support for common and powerful chips.

The work required to get this one piece into mainline over 5-6 years reveals why most chip vendors aren’t aiming for mainline by default:

> A few iterations of the rkcif driver later, the basic driver providing support for the PX30 VIP and the RK3568 VICAP was accepted (October 2025). After more than five years of development, including 25 iterations and three renamings, this was a major milestone. On the other hand, there was still a lot to do, of course. For instance, the Rockchip MIPI CSI-2 receiver unit that is coupled closely to the VICAP required a mainline driver as well.

It’s never as simple as submitting existing work upstream and making a few changes. It takes a lot of development and a willingness to rewrite everything, possibly multiple times, to track the goals of upstream.

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Palomides 2 days ago | parent | next [-]

I really feel like that should be table stakes if your entire business is making chips to run Linux, though

after working professionally with their stuff I'm really not a fan of Rockchip

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Aurornis 2 days ago | parent | next [-]

I wish everything was mainlined right away, too, but I’m realistic about what it takes to get that done.

There are chip providers that put more emphasis on mainline support but even those aren’t fully mainlined and their chips are generally much more expensive.

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le-mark 2 days ago | parent | prev | next [-]

Is there a SOC you prefer, why? Linux support seems about on par with most?

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packetlost 2 days ago | parent | prev [-]

Why is that? IME pretty much all of their software is a mess and the hardware has some bugs/issues iirc but is otherwise ok?

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mcmcmc 2 days ago | parent [-]

> all of their software is a mess and the hardware has some bugs/issues

Is that not enough of a reason?

	▲	packetlost 2 days ago \| parent [-]
		Fair!

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yjftsjthsd-h 2 days ago | parent | prev | next [-]

> why most chip vendors aren’t aiming for mainline by default:

> It’s never as simple as submitting existing work upstream and making a few changes.

If they had started by working with upstream, then they wouldn't have to go through unnecessary revisions trying to adapt the thing they already wrote.

	▲	Aurornis 2 days ago \| parent \| next [-]
		The part I quoted was from a team that was working with upstream, not the RockChip team. They were experienced with working with upstream and it still took them that long to do it.
	▲	mschuster91 a day ago \| parent \| prev [-]
		> If they had started by working with upstream LOL. It simply doesn't work that way. It's all about time to market. A BSP with a custom fork of the Linux kernel that barely works can be done concurrent with hardware development. But if you say as a manufacturer, we'll first get it upstream-supported by Linux and then release the hardware... by the time the quality is good enough for the proper upstream Linux kernel, the hardware is multiple generations outdated. And often enough, the software side is an afterthought. The BSP teams get thrown the hardware and told to "make it work", which all too often means having to do horrible hacks to the Linux kernel that would be completely unacceptable upstream. Even if they'd hire Greg KH himself, the fundamental problem remains that the BSP teams aren't asked if the HW designers can make the life of the BSP team easier. The one notable exception to this unholy mess, however, is Apple. And that is why Apple hardware seamlessly integrates within the ecosystem, why it is so performant and why it is so energy efficient.

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chucklenorris 2 days ago | parent | prev | next [-]

wow, i have a few of these laying around. i also bought some imx678 sensors i wanted to use with them. i tried pretty hard to make a driver work with these but it was impossible to get the isp working without modifying the kernel itself so i gave up. That convinced me to never buy hw that doesn't have drivers in the mainline kernel.

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2 days ago | parent | prev | next [-]

[deleted]

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tov_objorkin 2 days ago | parent | prev [-]

The product has a typical lifespan of 3–5 years, they just don't need LTS. RKISP(ImageSignalProcessor) is piece of code glued to the kernel, fast and cheap. The mainstream version provides proper integration with Linux multimedia subsystems.