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Comment by navait | Hacker News Reader

> Apple seems to consider macOS purely a client OS from which one ssh's to the outside world but not the other way round.

I'm not knowledgeable enough, but this seems a pretty reasonable assumption for 90% of use cases. And if this assumption holds, is it fair to say. I think what you're trying to say is "First of all, macOS power manages devices too aggressively for me"

> It looks like macOS suspends the BCM 57765 Ethernet controller and doesn't resume it upon reception of packets from the LAN.

What are the trade-offs of this decision? Could apple not do this and not change the battery life for anyone? Or would it benefit this case and adversely affect other cases?

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For a Linux driver it wouldn't be acceptable to compromise functionality like this as it's expected to work equally well on big iron as on laptops. So we have to tweak a lot more to achieve the same level of battery life.

Just to understand this, why wouldn't that be an acceptable compromise? As someone who uses linux on both a server and a laptop, I can tell you that when my laptop is unplugged, I'd much rather have that battery life than inbound ssh connection stability. I would imagine this is much the same for the vast majority of linux users. Could the lack of compromise be part of the problem?

If nothing's plugged in then many devices can indeed be suspended in some way, either by putting them in PCI power state D3hot or by cutting power if the platform supports it. Plug events are then signaled e.g. by an ACPI GPE (general purpose event, an interrupt sent by the platform to the OS).

The case I was referring to was with the Ethernet cable still plugged in. They seem to suspend the Ethernet controller but don't wake it when packets come in, presumably because the controller doesn't support that. The machine appears dead from the outside after a few seconds of inactivity.

Thank you for clarifying the case.

> They seem to suspend the Ethernet controller but don't wake it when packets come in, presumably because the controller doesn't support that. The machine appears dead from the outside after a few seconds of inactivity.

It seems like that would affect more than ssh connections, e.g. you wouldn't be able to receive email notifications.

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