Edge Computing Division Users Forum

I have come across a very strange problem. When I have
a Logitech camera plugged into the either of the rear USB 2.0
ports, the machine powers up about 3 seconds after being shut down
(shutdown via software). If I move the camera to any of the front USB 2.0
ports, the machine shuts down and stays off.

I have two IPCs and have tested both with two different Logitech cameras.
Also, when I have keyboard/mouse plugged into the same rear ports,
the machine stays off.

I should mention that I run Linux Mint 17.3 on both machine (have also tried Fedora23 and Mint 17.2). The typical command given is "shutdown -h now" or by the "Shutdown" menu option. The shutdown works fine with Windows 10.

Is there some sort of "power up on USB" in the BIOS that fires because of some
left over static in the camera?

Jens

It may have some connection to USB power functionality on Intense PC:
http://fit-pc.com/wiki/index.php/FAQ:In ... r_behavior

Intense PC USB port power behavior:
1. FACE Module ports – USB power always on (S0, S3, S4, S5).
2. Motherboard back panel ports – USB power on in S0, S3 but off in S4, S5.

S0 – active
S3 – sleep
S4 – hibernate
S5 – shutdown

And of course may be relevant to OS/SW settings and 3rd party camera used.

Solution found:

It seems to be related to the power saving features for USB in Linux.
What lead me to the solution was that I got a lot of messages like
usb 3-1.6: reset high-speed USB device number 4 using ehci-pci
in the log (which was slowing down the backgammon game gnubg!!!).

I changed a line in /etc/default/grub to
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash usbcore.autosuspend=-1"
and ran sudo grub-update.

Upon reboot the messages above were gone and now the machine powers off as it should.