Re:ARM64 Linux Workstation
by Gigachad on Friday March 03, 2023 @04:19PM
(#35015159)
Screen brightness works on the beta kernel. Speakers work but are disabled by default because there is a risk it could blow up the hardware
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Re:ARM64 Linux Workstation
by josephcsible on Friday March 03, 2023 @05:16PM
(#35015793)
> Speakers work but are disabled by default because there is a risk it could blow up the hardware
Wait, what? This sounds like a pretty egregious design flaw on Apple's part.
There's a good write up of it here https://social.treehouse.systems/@marcan/109917995005981968
Re:ARM64 Linux Workstation
by eyelidlessness on Friday March 03, 2023 @06:51PM
(#35016573)
The (very good) writeup conveys this much better than I could, but briefly for folks not inclined to click/read through: it’s a design trade off. Apple’s solution conditionally sends excess power to the speakers—higher power to achieve better sound under safe conditions, lower power to protect the speakers from damage. It’s quite clever (and quite effective, although I’m sure some audiophiles would disagree), but it’s not the kind of design you’d want to use without an equivalent solution. It’s also an unintuitive benefit of having a whole lot of compute headroom to play with, where you can create an intentional footgun that has meaningful benefits but risks physical consequences, and then spend some of that headroom to disarm the gun.
A pure software analogy (because that’s what I know better) would be something like: race a bunch of speculative variant algorithms in parallel, knowing that you’re “wasting” compute time, where the probability of speculation being more optimal than hand tuning is high and pathological cases have a “safe” straightforward deoptimization.
The tldr is that Apple drives the speakers way past their “always safe” level and then uses software in the OS to detect and dampen the uncommon sounds which could damage the speakers.
Resulting in exceptional audio performance. The Asahi Linux devs have already reverse engineered and implemented this safety system but there is a risk they have made a mistake or it doesn’t get enabled due to a bug.
Speakers are just things that move when you send electricity to them. It's not hard to blow up something like that if you try, especially if they heat up over time.
Re:ARM64 Linux Workstation
by josephcsible on Saturday March 04, 2023 @01:14PM
(#35023014)
Then why isn't this a problem with the built-in speakers of any non-Apple device?
It is, you're just not trying hard enough or you're using the official drivers that are software limiting it.