Seems that it's something to do with ACPI, since the "Shut Down" option behaves like "shutdown -H"
ubuntu@201403-14888:~$ cat /proc/acpi/wakeup Device S-state Status Sysfs node XHC1 S0 *enabled pci:0000:00:14.0 RP01 S4 *disabled pci:0000:00:1c.0 PXSX S4 *disabled RP02 S4 *disabled PXSX S4 *disabled RP03 S4 *disabled PXSX S4 *disabled RP04 S4 *disabled PXSX S4 *disabled PWRB S4 *enabled LID0 S3 *enabled
Seems that it's something to do with ACPI, since the "Shut Down" option behaves like "shutdown -H"
ubuntu@ 201403- 14888:~ $ cat /proc/acpi/wakeup
Device S-state Status Sysfs node
XHC1 S0 *enabled pci:0000:00:14.0
RP01 S4 *disabled pci:0000:00:1c.0
PXSX S4 *disabled
RP02 S4 *disabled
PXSX S4 *disabled
RP03 S4 *disabled
PXSX S4 *disabled
RP04 S4 *disabled
PXSX S4 *disabled
PWRB S4 *enabled
LID0 S3 *enabled