Yesterday I installed Kubuntu 18.04 on an old laptop (Toshiba Satellite L855D-S5220), and I'm having problems with the different motherboard ports. One problem is with the USB ports: they are preventing the computer from sleep, every time I click suspend the computer goes to sleep but then wakes up in an instant. Using
cat /proc/acpi/wakeup shows there are three USB ports enabled. Disabling them solves the problem of sleep, though they get reset to their initial values every time the computer reboots, so it is not a permanent solution. Another weird thing is with the power jack, every time I plug/unplug the laptop I get a message saying "No External Display":
which is really strange. I don't know if the problems are related or if they are caused by an acpi or driver issue (driver manager says the device doesn't need any proprietorial drivers). I really appreciate if someone can help with these problems (at least a permanent solution to the sleep issue). Thank you in advance.
Edit: USB devices can be connected and they work fine, however, transfer speed can not exceed 20 MB/s even through the USB 3.0 ports.