There's nothing I find particularly alarming here and the behaviour is in fact pretty much what I would expect for computing sin(x). Sure, maybe the doc needs updating, but nobody would really expect fsin to do much better than what it does. And in fact, if you wanted to maintain good accuracy even for large values (up to the double-precision range), then you would need a 2048-bit subtraction just for the range reduction! As far as I can tell, the accuracy up to pi/2 is pretty good. If you want good accuracy beyond that, you better do the range reduction yourself. In general, I would also argue that if you have accuracy issues with fsin, then your code is probably broken to begin with.
There's a difference between attacking a piece of software and attacking the author. I personally have no opinion on systemd (hell, I don't even know what init system I'm running atm), but I feel like any complaint people have should be directed at whoever *chose* systemd, rather than who wrote it. You can't blame someone for writing software. If you don't like it, don't use it and/or tell distros not to use it.
And since this is a camera passthrough, not an optical overlay, that's a glaring implementation flaw. Properly aligning the head tracking framerate, camera framerate, and rendering would let them render the virtual objects in lockstep with the physical ones (at least at speeds where motion blur isn't a significant issue; you can fake that by minimizing motion blur in the real image by using a short shutter time on the cameras).
So, they're locking out things that can brick the card (flash ROM/fuses, screw up thermal sensors) and apparently a hint of OS security (the Falcons that respond to userspace commands can no longer access physical memory, only virtual memory). The latter sounds somewhat bizarre, considering the firmware should be fully under the control of the driver, not userspace (I guess/hope?), but not unreasonable. Maybe there are software security reasons for this.
Nouveau is free to continue using its own free blobs or to switch to nvidia's. If they start adding restrictions that actively cripple useful features or are DRM nonsense, then I would start complaining, but so far it sounds like an attempt at protecting the hardware while maintaining manufacturing flexibility for nvidia. This isn't much different from devices which are fused at the factory with thermal parameters and with some units disabled; the only difference is that here firmware is involved.
NV seem to be turning friendlier towards nouveau, so I'd give them the benefit of the doubt. If they wanted to be evil, they would've just required signed firmware for the card to function at all. The fact that they're bothering to have non-secure modes and are only locking out very specific features suggests they're actively trying to play nicely with open source software.
After something like 20 years I finally found a system that won't run Debian unstable right now. My Panasonic Toughpad FZ-G1 magnesium tablet + iKey Jumpseat magnesium keyboard. Systemd and GDM break. Bought (for less than full price) because I am a frequent traveler and speaker and really do need something you can drop from 6 feet and pour coffee over have it keep working.
But because of this bug I have ubuntu at the moment, and am not having fun and am eager to return to Debian.
This file will self-destruct in five minutes.