[SOLVED] WiFi loss upon resume?

marav · 09-07-2021, 02:52 PM

Maybe, something interesting with dhcp=dhcpcd

In /var/log/syslog

Code:

NetworkManager[3451]: <warn>  [1631043602.4068] dhcp-listener: dhcp-event: (pid 3489) unhandled DHCP event for interface wlan0
dhcpcd[3490]: ps_ctl_dispatch: cannot handle another client

Problems with NM/dhcpcd seems to be more or less recurrent ...

https://www.linuxquestions.org/quest...ks-4175632561/

https://www.linuxquestions.org/quest...er-4175576144/

mcnalu · 09-08-2021, 03:36 PM

I got this same issue and in my case, before finding this thread, I went for option 2 ie setting "dhcp=dhclient" in /etc/NetworkManager/conf.d/00-dhcp-client.conf and it solved the issue for me.

sombragris · 09-10-2021, 11:18 AM

I am also bitten by this issue. Very annoying.
Will try one of the workarounds next time I sleep the PC.

SteveK1979 · 09-11-2021, 06:30 AM

Morning,

I've recently installed slackware-current and also having this issue on the wlan interface when my Dell laptop wakes from sleep.

Quote:

Originally Posted by mcnalu

I got this same issue and in my case, before finding this thread, I went for option 2 ie setting "dhcp=dhclient" in /etc/NetworkManager/conf.d/00-dhcp-client.conf and it solved the issue for me.

I've done with this option, at least partially because I'm familiar with dhclient from the past. It seems to have resolved the issue for me.

Cheers,
Steve

trollog · 09-11-2021, 12:30 PM

What I am wondering is:

Will there be an upstream fix for this, or is the config file tweak the solution that will
go into 15.0?

Which will be the final fix here?

marav · 09-11-2021, 12:38 PM

Quote:

Originally Posted by trollog

What I am wondering is:

Will there be an upstream fix for this, or is the config file tweak the solution that will
go into 15.0?

Which will be the final fix here?

https://gitlab.freedesktop.org/Netwo...r/-/issues/796

Code:

I would still first fix the dhcp-listener warnings. 
The simplest solution seems to use dhcp=internal in NetworkManager.conf. 
That is the default, and there are few reasons to choose anything else

marav · 09-11-2021, 01:52 PM

Ok, I got it

I read it 10 times without really seeing it ...

Code:

* The dhcpcd plugin now requires a minimum version of dhcpcd-9.3.3 with
  the --noconfigure option. Using an older version will cause dhcpcd to
  exit with a status code of 1.

https://gitlab.freedesktop.org/Netwo...b/1.32.10/NEWS

So,

Code:

--- 00-dhcp-client.conf 2021-09-11 20:50:47.337126759 +0200
+++ 00-dhcp-client.conf.new     2021-09-11 20:50:39.594224100 +0200
@@ -1,7 +1,7 @@
 [main]
 # Choose a DHCP client below. Upstream recommends internal, but results may vary.
 # dhcpcd is the DHCP client usually used by Slackware:
-dhcp=dhcpcd
+dhcp=dhcpcd --noconfigure
 # dhclient is the ISC reference DHCP client, part of the dhcp package:
 #dhcp=dhclient
 # This is a simple DHCP client that is built into NetworkManager:

Work like a charm after suspend/resume here

It would be great if @Pat can provide it with the next rebuilt ;-)

pghvlaans · 09-11-2021, 02:38 PM

Wow. "dhcp=dhcpcd --noconfigure" is working here as well, and there's no sign of any dhcp-related processes in "ps ax" on either side of resume.

Loomx · 09-11-2021, 03:39 PM

Good find :-)

I'm wondering if it is better to add the "--noconfigure" option to /etc/dhcpcd.conf instead?
Otherwise every forum/wiki/blog post that gives a dhcpcd command line to run will trip over the same error.

I think the line to add would be:

Code:

env if_configured=false

I haven't tested it yet though

montagdude · 09-11-2021, 10:58 PM

Quote:

Originally Posted by ctrlaltca

It seems like networkmanager doesn't kill the old dhcpcd while suspending, and after resume it tried to start a new client that fails since another instance of dhcpcd is already rinning.
Changing the dhcp client used by networkmanager in /etc/NetworkManager/conf.d/00-dhcp-client.conf could workaround this, but i suppose that there's a root cause that needs proper fixing here.
It's not really solved yet.

EDIT: i can confirm that setting "dhcp=internal" in /etc/NetworkManager/conf.d/00-dhcp-client.conf is a workaround for the problem

Same problem here. The workaround is working for me too so far.

marav · 09-12-2021, 09:50 AM

From what we can see, NetworkManager Devs seems to know better than anyone else how to do dhcp ...

Code:

    /* Don't configure anything, we will do that instead.
     * This requires dhcpcd-9.3.3 or newer.
     * Older versions only had an option not to install a default route,
     * dhcpcd still added addresses and other routes so we no longer support that
     * as it doesn't fit how NetworkManager wants to work.
     */

https://github.com/NetworkManager/Ne...-dhcp-dhcpcd.c

And after the problems that many of us have encountered
It might not be a bad idea to switch permanently to dhcp=internal to get away from it all

sombragris · 09-12-2021, 12:06 PM

Quote:

Originally Posted by chrisretusn

Well glad to hear I'm not the lone stranger. Had this issue with my laptop that I hibernate. I tried the dhcp=internal setting, it does not work for me. I still have to reboot or:

Code:

/etc/rc.d/rc.networkmanager stop
killall -9 dhcpcd
/etc/rc.d/rc.networkmanager start

I confirm this workaround works as advertised in my case. Very annoying indeed. Thanks for providing us a way to get out of it.

rworkman · 09-12-2021, 12:16 PM

Quote:

Originally Posted by marav

Ok, I got it

I read it 10 times without really seeing it ...

Code:

* The dhcpcd plugin now requires a minimum version of dhcpcd-9.3.3 with
  the --noconfigure option. Using an older version will cause dhcpcd to
  exit with a status code of 1.

https://gitlab.freedesktop.org/Netwo...b/1.32.10/NEWS

I too had seen it without actually seeing it. That's why we upgraded to dhcpcd-9.4.0, as the way I had read that statement was "we need at least 9.3.3 in order for this to work."

My impression was that NM would exec dhcpcd with the --noconfigure option on its own, given that it expects the option to be there. A reading of src/core/dhcp/nm-dhcp-dhcpcd.c in the NM source indicates that is indeed what should be happening, so it seems that we have a different problem.

marav · 09-12-2021, 08:04 PM

Quote:

Originally Posted by rworkman

I too had seen it without actually seeing it. That's why we upgraded to dhcpcd-9.4.0, as the way I had read that statement was "we need at least 9.3.3 in order for this to work."

My impression was that NM would exec dhcpcd with the --noconfigure option on its own, given that it expects the option to be there. A reading of src/core/dhcp/nm-dhcp-dhcpcd.c in the NM source indicates that is indeed what should be happening, so it seems that we have a different problem.

This doesn't help for our problem, but according to NetworkManager 1.32.10 ./configure --help

--without-resolvconf
seems to be
--with-resolvconf=no

and
--enable-json-validation
doesn't seems to exist anymore

PS : I have no skill to determine or interpret whether it is good or not ...

marav · 09-13-2021, 08:19 PM

Quote:

Originally Posted by pghvlaans

Wow. "dhcp=dhcpcd --noconfigure" is working here as well, and there's no sign of any dhcp-related processes in "ps ax" on either side of resume.

Solved !

Quote:

Mon Sep 13 18:04:35 UTC 2021
...
n/NetworkManager-1.32.10-x86_64-2.txz: Rebuilt.
00-dhcp-client.conf: Add the --noconfigure option to dhcpcd, or else the
network won't return after suspend/resume.