Strange behaviour after resuming from suspend with no network connection

09 October 2021, 05:46:42

Hello everyone, and thank you to all those involved in making this distro happen.

I did a search on the forums for "resume from suspend" hoping to catch a result that might be related to what I'm observing. I didn't find anything and hence I'm posting this so that maybe the appropriate developer is notified.

I have tested the following scenario across two days and the testing began because of a simple thing, my network cable connector clip broke off and the cable falls out sometimes.

The pattern of behaviour I have observed is this....

If the computer goes into suspend mode and the network cable falls out or is removed then upon waking from suspend the password can not be validated, or at least appears to not validate. The password prompt request remains on the screen. During one test I waited several minutes before attempting to enter the password again and then press enter, and still there was not response/change, not until I plugged in the network cable (This was after the machine had already woken up and suggesting that it required the cable and network connection to validate the password).

I am still trying to catch other errors that might be related to this. For example, unplugging the network cable before suspending the machine, waiting a few minutes, and then resuming the machine from suspend, on five tests, yielded no login screen at all, instead the access to the desktop/machine was immediate without a login. I might test this later with a longer wait period of at least half hour and see if the result is the same. The screensaver, by the way, is set to lock the screen after 2 seconds of delay from the moment the screensaver activates, which is after 15 minutes. And so I don't think the screensaver is the issue here, but I could be wrong.

Not sure what causes what I'm reporting, but it might be a security issue for some people.

For all it matters the following are details that might be relevant....

Machine is Gigabyte B85M-D3H. 16GB RAM. i5-4460.

lspci lists the following network card...

02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 06)

The installation media I used was the Cinnamon release. I only installed the OS onto the machine two days ago and so have not installed a lot of other stuff that may have contributed to the problem. And so I also don't know if this is related to Cinnamon Desktop. The machine performed an update today and still the same thing is occurring.

I don't have the opportunity to further investigate this now by performing reinstalls, and tinkering around too much. Maybe this post is useful to someone.

I don't intend to keep this installation for the longer term if I don't find a solution because I require the security of a working login and suspend, definitely not one that requires me to have a network/internet connection to work properly. Although I haven't explicitly turned off the router to check if the internet connection itself is a requirement or merely a cable to be plugged into the network connector on the motherboard, just letting the reader know of this here.

If anybody wants me to test things further then you are welcome to try and contact me before I format this drive.

Thanks in advance.

Re: Strange behaviour after resuming from suspend with no network connection

Reply #1 – 09 October 2021, 10:33:29

... PS - I should add that I installed the OpenRC version of the Cinnamon release.

Re: Strange behaviour after resuming from suspend with no network connection

Reply #2 – 10 October 2021, 16:53:19

It may be related to cinnamon. Install a minimal DE like lxde or lxqt and try suspend-resume from within it to confirm. Another culprit could be lightdm's locker (light-locker) interfering with the DE's native locker, try uninstalling light-locker.