Wednesday, November 24, 2021

Wake me up before you go-go or better yet, don't

In the few months I have noticed my Fedora notebook wake up in my backpack.  It has also awakened in the middle of the night and by morning the battery was nearly depleted. I first noticed the wake up when I paired another laptop with it.  When the other laptop powered up in to the operating system, my Fedora notebook would wake up.  I made a connection between wake on demand and bluetooth.

Initially I figured I had a device in the house that was paired with it.  I fired up Wireshark on the bluetooth adapter and found that every time that laptop awakened, there was a broadcast event from an Apple device. 

I began to suspect that I had an Apple device paired with it.  I turned off bluetooth from all Apple devices and it still awakened a few seconds later.

However, just the other day I found it awakened readily even far away from my house.

I repeated a Wireshark/bluetooth capture and sure enough, another Apple device.

I investigated wakeup parameters in the /sys tree and found this works to keep the laptop from waking on bluetooth events.

As root: find /sys/devices -name wakeup | grep usb2/2- | while read F; do echo disabled > $F; done

UPDATE 2021-12-31 - I have recently replaced the operating system with a newer release. I will watch and see if the issue persists.




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