Waiting up to X more seconds for network configuration

Embedded Devices Linux
,
1

How can I turn off the network waiting for my ccimx6ulsb at boot time?

Unfortunately, I cannot find a file like “/etc/init/failsafe.conf” in my system.

2

What exactly do you want to wait for?

3

I would like to wait only about 30 seconds if no RJ45 interface is connected

4

I do not believe anything like this is implemented by default. You’d have to implement NetworkManager-wait-online.service. The binary that is the core if this service nm-online is present in the roots:

https://developer.gnome.org/NetworkManager/stable/nm-online.html

as you can see in: https://github.com/aababilov/systemd/blob/master/system/NetworkManager-wait-online.service

it is basically
/usr/bin/nm-online -q --timeout=30
So you should be able to create a startup script that is called after network manager is started and run the line above in that script.

5

The network manager is not present in my build, so it cannot trigger the wait. Do you have another idea?

6

Well, the idea should be the same. In one of the startup scripts, run a loop with delay checking for link status, parsing output of something like
ethtool eth0
or
ip link show eth0

7

I’m sorry i think I spoke out of turn. I have the problem that my Linux system only boots after 120 seconds if the RJ45 connector has no link. I would like to reduce this time to 30 seconds. I have already searched the file system for the script but unfortunately I cannot find it.

Here is a small excerpt from the boot process:

mca-rtc mca-cc6ul-rtc: setting system clock to 2020-06-11 08:23:56 UTC (1591863836)
SMSC LAN8710/LAN8720 2188000.ethernet-1:00: attached PHY driver [SMSC LAN8710/LAN8720] (mii_bus:phy_addr=2188000.ethernet-1:00, irq=POLL)
IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
Waiting up to 110 more seconds for network.
Waiting up to 100 more seconds for network.