Everything I have googled on the use of this file suggests that it should contain a long list of device names, and this is indeed the case for all the distros on my desktop machine. However Dragora on my Samsung laptop shows only three devices in this file, five if I activate USB wakeup in the BIOS. There are no other BIOS options for enabling wakeup devices.

The devices that I can identify are the power button, the ethernet card and two USB root hubs. The fifth one is called MBTN and is obviously some kind of button but I can't find out from the /sys hierarchy precisely what it is. The lid button (LID0) is not included, nor are the keyboard and trackpad (which I think are PS/2 devices).

I have now got the machine to go to sleep when the lid is closed. I would like it to wake up when I open the lid again or (failing that) when I touch a key. But with no relevant entries in the wakeup file, that doesn't seem to be possible.

I have tried echoing LID0 into the the file, which is what you normally do to enable a device as a wakeup device, but it doesn't seem to work if the device has no entry to start with. It doesn't give me any error messages but it has no effect.

Hazel,

On my Samsung N220:


There is no LID0 listed. It must be referenced somewhere surely?

EDIT:

This may help you:
http://askubuntu.com/questions/15240...keup-permanent

For those who are updating to the 3.2 kernel (which should be everyone due to the recent root exploit), you'll notice your USB wakeup is probably broken.

They changed the default wakeup policy (http://www.spinics.net/lists/linux-usb/msg53661.html), so you'll need to make a couple of changes:
You no longer need to enable wakeup in /proc/acpi/wakeup, it's enabled by default
you need to enable wakeup for the USB hub in addition to the device in /sys/bus/usb/devices/*/power/wakeup

So, this:

becomes:

………………………….................................................
You have probably seen this already:

https://wiki.archlinux.org/index.php...pending_to_RAM

1 members found this post helpful.

I have that file too. That's how I know that the lid switch is called LID0. I can make the switch act as a suspend device by putting a case statement in my default acpi handler: if the LID0 event occurs and the LID0 file does not contain the word "open", the computer runs pm-suspend and goes to sleep. But you can't do a wakeup that way.

Yes, I've seen that one. But their problem was rather different. The devices the poster was interested in were in the wakeup file; they just kept getting disabled. The solution was a suspend hook that re-enabled them all. In any case, the devices I am interested in (lid switch and keyboard) are not on the usb bus. On this machine, keyboard and trackpad are PS2 devices.

The Arch wiki looks very promising. Lots of meat! But everything is angled towards systemd and I don't know how much of it is relevant to other init systems (Dragora uses runit). But I'll do some browsing there and see if I can find anything that might work with my system. Thanks for your help.