Earlier quoted context omitted.
I don't know what the deal is with Linux and cameras. I've got Fedora installed on this old Retina MBP and apparently Linux somehow stopped supporting the built in webcam. I've never heard of a device losing Linux support but here we are.
Once the code is in the mainline kernel tree, things tend to stay supported indefinitely. Some devices "work" without having real support by having some binary blob or third party code which is written against a specific kernel version. The code has to be updated when the kernel changes, which is why it's supposed to be in the kernel tree, but because it isn't the kernel developers don't know anything about it and ar…
Not saying pushing mainline is bad. But assumption there's any kind of "support" is wrong. Code is there. That's all. You have to support it if you want it to work.
(This is very particular to HW/drivers support, Linux core is supported well, I guess.)