That can happen after a few seconds like many people have described, or after a few minutes or hours. The display remains turned off, only when I press keyboard or move the mouse it gets turned on.
What can be the reason?
I'm using a bluetooth mouse, maybe it gets connected to it when it's asleep because I put them in a bag close to each other? However, I think even if it is, it's not the only reason.'
UPDATE:
$ cat /proc/acpi/wakeup
Device S-state Status Sysfs node
LID S3 *enabled platform:PNP0C0D:00
IGBE S4 *enabled pci:0000:00:19.0
EXP3 S4 *disabled pci:0000:00:1c.2
XHCI S3 *enabled pci:0000:00:14.0
EHC1 S3 *enabled pci:0000:00:1d.0
What should I disable to allow waking up only by pressing a key on the keyboard?
I suppose LID is your laptop's lid, so leave that on so you can wake it up by opening the lid. IGBE is the network card, so it doesn't seem relevant to your problem. I don't know what EXP3 is but it doesn't matter because it's disabled. This leaves us with XHCI and EHCI. These two are the USB hubs (one is USB 2.0 the other 3.0).
To disable wakeup from any USB device, just add the following to
/etc/rc.local
:You can also execute the commands as root and then put the laptop to sleep and see if it stops from waking up by itself. Try moving the mouse before and after you make this change to see if it helps.