I have been seeing an issue, which I am not sure is only in my environment
If others have see it please comment. Details below:
What:
any device on /dev/ttyACM0, with a USB OTG cable plugged in (i.e. Edison is acting as USB master),
a reboot ( regardless of any activity going on in the USB port) appears to make Edison shut down the /dev/ttyACM0.
A second reboot wakes up this /dev/ttyACM0. This is very consistent, i.e. the second reboot wakes up /dev/ttyACM0.
Again a third reboot shuts down ACM0 and a fourth re-awakens ... and so on.
How to reproduce:
Hardware:
My Edison is using a minibreak out board, with power being supplied by external power via J21.
I have an USB A female to Micro A male 10-00649 839-1105-ND (as per Edison docs.), with micro A plugged into Edison.
I have a USB slave device plugged (can be a phone with serial terminal activated on USB port) into USB A female.
Software:
Debian ubilinux installed per information available on this forum, on other threads.
Once the Edison is booted, I attempt to read and write the slave device. The failures are
noted on the odd numbered reboots.