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USB not working properly after reboot

Posted: Sun Jun 16, 2019 11:47 am
by fpeelo
I am using a FITLET2-CJ3455, SN 1181129-02668 with Linux Mint 19.1 Tessa.

There are 4 USB sockets on the fitlet. What's plugged into them is: beside the HDMI port, a keyboard and a mouse; beside the audio socket a 4TB hard drive; beside the power button a Patriot 7-port USB3.0 hub,

Yesterday I did an update, and since there were a lot of packages being updated, and services restarted, I rebooted the PC. Call me superstitious if you like but I do think the occasional reboot is worth doing, especially if glibc or the linux kernel gets updated. On reboot the devices plugged into the USB hub were not recognised. I power-cycled. A memory stick that was plugged into the hub at reboot was recognised, but when I plugged another device in, the new one wasn't. I did a
dmesg | tail
and it contained a suggestion to power-cycle. Unfortunately I didn't record the dmesg. I unplugged everything from all the USB ports on the fitlet, pulled the power, plugged it back in, and after reboot I could plug everything in again.

I recall that I used to have the mouse and keyboard plugged in the front, and they used to have problems, but that's "anecdotal", it's a couple of months ago and I don't trust my memory 100% back that far. Plugging them in the back seemed to work.

Fortunately I don't reboot this machine very often. (That's why I got a passively-cooled low-power-consumption PC -- so it could be permanently on, I can ssh in when I'm not at home and so on :) ) But I do reboot sometimes. I bought a VESA panel to fix the computer to the back of the monitor, and unplugging all the USB things every time I want to reboot would be a pain. I had a look at the errata and ECNs, and I didn't see anything like this, but I want to ask anyway whether this is a known thing and if there is a workaround?

Re: USB not working properly after reboot

Posted: Tue Jun 18, 2019 12:22 pm
by tamir
There is no known issue related to the USB ports as you described on your fitlet2.

The USB2.0 ports can supply maximum of 1amp together while the USB3.0 ports can supply up to 3amp together.
If the devices connected to your hub are reaching the USB port's supply limitations, then it wouldn't work well.

Re: USB not working properly after reboot

Posted: Sat Jun 22, 2019 7:11 am
by fpeelo
Thanks for the reply.

The keyboard and mouse shouldn't take much power, and the 7-port USB hub and hard drive have their own power supplies. So I hope it's not that.

I've got a 4-port USB3 hub, so now all 4 devices go into one USB3 socket on the Fitlet. Will see if that makes a difference, next time I have to reboot. Fingers crossed it all works. Worst case, I will only have one cable to unplug when I power-cycle.