Sometimes lose networking after resume from suspend

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aussie
Posts: 74
Joined: 2018/06/30 12:21:31

Sometimes lose networking after resume from suspend

Post by aussie » 2020/06/25 12:16:42

Hello,

I have lost my wired connection about 5 times when resuming from a suspend. I get a message about a kernel error occurred.
kernel crashed
WARNING: CPU: 0 PID: 24971 at drivers/net/ethernet/intel/igb/igb_main.c:756 igb_rd32+0x7c/0x90 [igb]

kerneloops 3
I have tried: systemctl start network.service and it says it is connected, but when I try to bring up a web page it times out looking up the webpage.

The wireless still works which is normally disconnected. I can connect and bring up webpages though wireless.

Is there any way to get back my wired connection without having to reboot?

Aussie

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TrevorH
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Re: Sometimes lose networking after resume from suspend

Post by TrevorH » 2020/06/25 13:52:16

Which kernel? Output of uname -r ?
CentOS 6 will die in November 2020 - migrate sooner rather than later!
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
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aussie
Posts: 74
Joined: 2018/06/30 12:21:31

Re: Sometimes lose networking after resume from suspend

Post by aussie » 2020/06/26 00:18:41

Hi TrevorH,

3.10.0-1127.10.1.el7.x86_64

Aussie

tunk
Posts: 725
Joined: 2017/02/22 15:08:17

Re: Sometimes lose networking after resume from suspend

Post by tunk » 2020/06/26 11:16:34

Don't know if it will make any difference, but you could
try to run yum update (and reboot) to get the newest kernel.

aussie
Posts: 74
Joined: 2018/06/30 12:21:31

Re: Sometimes lose networking after resume from suspend

Post by aussie » 2020/06/26 13:56:49

Hi tunk,

I updated to the latest kernel, but still have the problem.

It seems to be a bug in the intel ethernet driver. But it says the bug can not be reported "kernel maintainers are unable to diagnose tainted reports. Tainted modules vmnet vmmon" These kernel modules are for my VMPlayer program.

I would be interested in just getting my wired connection working again without having to do a reboot.

Aussie

DaveHighland
Posts: 13
Joined: 2016/04/06 20:08:05

Re: Sometimes lose networking after resume from suspend

Post by DaveHighland » 2020/06/30 20:37:35

To get your network back on-line, try the nmcli command (Network Manager Command Line Interface). See the man page for usage.

I, too, am having problems with suspend/resume, and I've been troubleshooting it. From my internet research, I've learned that when some hardware interfaces are powered down during suspend, their status/control registers lose their contents, and the device driver (often clueless) doesn't save the register state on suspend and then restore the register state upon resume. In my case, the ethernet interface (among others) has this problem and that makes resuming buggy. I found this website that shows how to write systemd unit files that can run before suspend and after resume to compensate for these problems: https://forum.manjaro.org/t/solved-qca6 ... nd/66232/4 (Scroll down to the post by qwaler that begins "Not really" and read the final unit file solution he found.) This RH webpage, https://access.redhat.com/documentation ... Unit_Files, has detailed information about the syntax and structure of these unit files. Scroll down to section 10.6.1, "Understanding the Unit File Structure".

In my case, I haven't written and installed such unit files yet; I've first been manually testing the technique by typing these commands in a terminal window to initiate a suspend:

Code: Select all

nmcli networking off
systemctl suspend
You can type "man nmcli" for excruciating details, but basically the "networking off" command shuts off the wired and wireless networking interfaces (presumably in a way that units using the interfaces don't get too torqued about it).

Later, after I press the power button on the computer to resume, I type this command into the terminal window:

Code: Select all

nmcli networking on
And that seems to correctly restore the networking interfaces.

My computer still has suspend/resume issues, but I'm tracking down the problem interfaces one by one. The sound chip has a similar state problem, so before suspend I've been using this additional command:

Code: Select all

pulseaudio --kill
and after resuming I type these additional commands:

Code: Select all

alsactl init
pulseaudio --start
The alsactl init command, according to its man page, tries to initialize all sound devices to a default state. Then I follow that with the pulseaudio --start command so that pulseaudio is fully initialized and not assuming anything about the state of the device from before the suspend.

I'm still having an occasional problem with the imjournal service not freezing during the suspend, but I'm working on it.

Hope this helps you. :)

aussie
Posts: 74
Joined: 2018/06/30 12:21:31

Re: Sometimes lose networking after resume from suspend

Post by aussie » 2020/07/01 06:07:10

Hi DaveHighland,

Many many thanks for the information.

I've give it a try.

Thanks again,
Aussie

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