Linux 進入 S3, S4 的方式

Linux 進入 S3, S4 的方式有兩種：

使用桌面icon:
hibernate: 右上按電源, 按住alt會有hibernate的icon

S3:
 1. pm-suspend
 2. echo 3 > /proc/acpi/sleep

S4:
 1. pm-hibernate
 2. echo 4 > /proc/acpi/sleep

Ubuntu 16.04&18.04
# systemctl suspend
# systemctl hibernate

Ubuntu 18.04 hibernate 回復不成功:

1) 安裝OS時需要有swap partition, 並確認swap uuid 

$ ls -l /dev/disk/by-uuid

2) 修改Grub及initramfs

$ sudo vim /etc/default/grub

================================================================

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash resume=/dev/disk/by-uuid/439e82fd-804e-4e9a-8922-2ea49e678fa1"

================================================================

$ sudo update-grub

$ sudo update-initramfs -u

$ reboot

有時會遇到 USB 裝置無法將系統在 S3 或 S4 時 wakeup, 必須 enabled 裝置

* 查詢 USB Device Number *
[root@localhost ~]# lsusb
Bus 001 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 002 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 003 Device 002: ID 0b38:0010 Gear Head 107-Key Keyboard
Bus 003 Device 003: ID 046d:c03f Logitech, Inc. M-BT85 [UltraX Optical Mouse]
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub

* 查詢 USB Device 在 /sys 位置 *
[root@localhost ~]# grep c03f /sys/bus/usb/devices/*/id*
/sys/bus/usb/devices/3-3/idProduct:c03f

[root@localhost ~]# cat /sys/bus/usb/devices/3-3/power/wakeup
disabled ==> 預設是 disabled

* enabled Device *
[root@localhost ~]# echo enabled > /sys/bus/usb/devices/3-3/power/wakeup
[root@localhost ~]# cat /sys/bus/usb/devices/3-3/power/wakeup
enabled

有時會遇到滑鼠無法 wakeup 應該是相容性問題