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Comment by leidenfrost | Hacker News Reader

Imho the only relevant parts left are: Sleep (which is being tackled right now), USB-C Extra displays (Also WIP) and Hardware Decode for video.

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Linux 2013: Sleep support doesn’t work quite yet, but it’s being worked on right now

Linux 2023: Sleep support doesn’t work quite yet, but it’s being worked on right now

You can thank Microsoft for the current mess. S0ix (aka "Modern Standby") doesn't even work right on Windows.

Linux Laptops with no S3 support use S2, not S0 as on Windows. Still buggy as hell. My XPS sometimes loses 70% in 4 hours standby and then just ~5% in 2 days of standby. Most of the time the battery drain is insane. At least the overheating in bag issue never occured to me.

I've still had better experiences with closed laptop lids when using Linux in comparison to windows in the last decade.

and audio and screen brightness at least...those don't work on my M2 setup.

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

> 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

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.

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.

They either cap them at the “always safe” level which results in much less volume, or you actually can blow them up but you just haven’t played the right sound to trigger it.

> and audio...

Overall tip for anyone using Linux and having issues with audio... USB Audio is magical and works wonder. I never bother with the computer's in-board sound: it's USB Audio immediately through a DAC. Works fine. Apple sells $10 USB-C-to-3.5mmjack DAC which are basically a tiny cable (for anyone lamenting it's "too bulky" to have a full-on DAC next to their laptop).

For desktops: problem doesn't even register. Just bypass the audio components on your motherboard and use a proper DAC.

As an added bonus computers are particularly electrically noisy and a DAC is a great way to do away with all that the noise.

So my advice: just use a DAC with Linux. Plug it in. Marvel at "dmesg" showing "USB Audio" and enjoy quality sound.

Be somewhat careful what USB audio device you buy. I've had multiple of these and some of them have tons of EM noise, which is very obnoxious.

> I've had multiple of these and some of them have tons of EM noise, which is very obnoxious.

Ah darn yup! If there's one thing I'd expect from these is to not be noisy! FWIW I'm using a CambridgeAudio DAC and, well, CambridgeAudio is supposed to be a good brand when it comes to audio stuff (amp is CambridgeAudio too).

I've been pretty happy with Dragonfly[0]. Tho they don't come cheap.

I have had the black and am currently on the Red, I noticed the difference so I think it's worth it. Have not tried the cobalt.

[0] - https://www.audioquest.com/dacs/dragonfly/dragonfly-cobalt

> CambridgeAudio DAC

It looks like these start at $250? I'd expect them to work well. I'm more wary of this pricepoint:

> Apple sells $10 USB-C-to-3.5mmjack DAC

I've gotten a lot less EM noise with builtin soundcards than cheap USB DACs, but YMMV.

> cheap USB DACs

These numbers are several years old now, but Apple USB-C DACs do perform very well overall regardless of price point: https://www.audiosciencereview.com/forum/index.php?threads/r....

EM noise is something that someone would notice, so I'm sure Apple would have nuked it from orbit until it's completely imperceptible.

Yeah, to be clear I expect the Apple ones do fine. The ones I had issue with were not Apple.

> It looks like these start at $250? I'd expect them to work well.

Price inflated, like the price of nearly everything. I paid mine 150 EUR back in the days (still not cheap but not either the 4 digits high-end audiophile stuff).

The thing is: you want thing to work fine from Linux's side and in my experience USB Audio on Linux just works.

I'm sure there are other brands/models at reasonable price points.

I've been doing this to get my computers connected to a KVM to share speakers. Works pretty well, bought a Soundblaster for nostalgia sake.

This will use 10-15% CPU (intel and M1 Pro).

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