Machine: Macbook Air Late 2015
Ubuntu 18.04
Problem Situation: Laptop lid is left closed for quite some time (at least an hour or so). Open the lid, press power button or keyboard. Nothing happens. Screen is blank black. Keyboard lights are off, the Apple logo is not lit up and no sound or anything.
I had to press the power button for a while, and then press it again for it to start. And then log in as usual and all the running windows or operations previously are no longer there. As if it was turned off and restarted.
From the syslog:
May 3 19:33:23 MacBookAir systemd[1]: Reached target Sleep.
May 3 19:33:23 MacBookAir systemd[1]: Starting Suspend...
May 3 19:33:23 MacBookAir systemd-sleep[5978]: Suspending system...
May 3 19:33:23 MacBookAir kernel: [ 6650.590931] PM: suspend entry (deep)
This does not always happen though, about 40% chance in average every time it goes into hibernate. At times it is able to wake up from the suspend/hibernate with no problem.
I thought it was a swap issue because the /swapfile size initially was 2GB which i assumed was not enough to cater the 8GB ram of this machine. So i've increased the swap size to 8GB. But turns out it's still doing the same issue.
besides increasing the swap, i've also change the grub file and add resume=UUID=48df08d6-b2c0-44b4-acc6-e392a9f88fa6 resume_offset=2467840 resumedelay=15, so now the line looks like this:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash resume=UUID=48df08d6-b2c0-44b4-acc6-e392a9f88fa6 resume_offset=2467840 resumedelay=15"
The procedure above was obtained from the following articles:
Configuring Lubuntu 18.04 to enable hibernation using a swap file
How do I increase swapfile in Ubuntu 18.04?
I've tried to force hibernate with systemctl hibernate and suspend with systemctl suspend, but there's no problem waking up from this.
I still can't figure out what causes the problem, opting out not to use hibernate is not an option because the laptop's battery capacity is only about 50%. So, hibernate really does help a lot.. if it works.
