Ubuntu

How to determine which interface/device initiated a wake

Asked by malch

I am having problems with spurious wakes from S5. They are infrequent so testing any one theory can take hours or days.

Clearly, what I need is the ability probe the system logs to see what initiated the wake. However, I cannot find anything recorded via syslog, dmesg or journalctl. In fact, if I deliberately wake the system (e.g. with WOL) I cannot find any reflection of that event in any of the logs either.

Since I'm starting from S5, it seems that some hardware must be waking the kernel via a Power Management Event(PME). Later, the kernel may or may not interrogate the device to obtain further data about the event and its causation. If these events are recorded anywhere, I can't find them.

My problem may be very specific to my particular hardware or configuration but it's clear from my research that many others have struggled with tracking down unwanted/unexpected wakes and it seems to me there's a strong need for something along the lines of Windows "powercfg -lastwake".

I'm interested in addressing the general case more than my specific problem (although a solution to the latter would obviously be very welcome).

Machine: Intel NUC (Broadwell) NUC515RYH with latest BIOS
OS: Lubuntu 15.04 beta
Kernel: X64 3.19.0-9-generic

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actionparsnip (andrew-woodhead666) said : 		#1

I suggest you report a bug. Vivid is not ready and not stable

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malch (malch) said : 		#2

Sorry, but I don't think that makes any sense at this point. There may be a bug -- most likely in the BIOS or the kernel. But it could lie in a controller or peripheral and the problem could even be a symptom of faulty hardware. The fact that I'm running Vivid also complicates matter but it's necessary because of the new Broadwell and HD6000 hardware. I really don't feel I yet have enough information to submit a proper bug report or even know where to submit it.

My original question was: How to determine which interface/device initiated a wake.

I think it's a valid question and one that has been asked before but as best as I can tell, never answered in any meaningful way.

I'd be very grateful to anyone willing to take a shot at answering the question. If you feel this is simply the wrong forum, I'd welcome any suggestions as where I might take it.

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Launchpad Janitor (janitor) said : 		#3

This question was expired because it remained in the 'Open' state without activity for the last 15 days.