Some thing connected to my machine is waking it up frequently even when I am not around so I decided to look into it.

The devices that are allowed to wake linux can be found in two ways.

1. By reading /proc/acpi/wakeup. Write echo <device> | sudo tee /proc/acpi/wakeup to toggle a device.

2. A second approach is to do grep . /sys/bus/usb/devices/*/power/wakeup | grep enabled

Find USB Device id from dmesg or lsusb by running, sudo dmesg | grep <device name>

Disable by running, echo 'disabled' | sudo tee /sys/bus/usb/devices/<device-id>/power/wakeup