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I've connected a LTE usb dongle at raspberry pi 4B which has raspbian buster 10.
I have created a initialization script which consists of the following :

modprobe qmi_wwan
echo 'xxxx xxxx' > /sys/bus/usb/drivers/qmi_wwan/new_id
ip link set dev wwan0 down
echo Y > /sys/class/net/wwan0/qmi/raw_ip
ip link set dev wwan0 up
qmicli --device=/dev/cdc-wdm0 --device-open-proxy --wds-start-network="ip-type=4,apn=apn" --client-no-release-cid

When I run it manually from the home directory

sudo ./init.sh

it works fine.

However when I try to run it as boot up script I always get the error :

couldn't create client for the 'wds' service: CID allocation failed in the CTL client: Transaction timed out

Firstly I tried to add the running of the script at the /etc/rc.local file.

Then I created a service to start up after boot up via systemd. The service file is basically the following:

[Unit]
Description=initialization script
After=remote-fs.target
After=syslog.target

[Service]
Type=simple
ExecStart=/bin/sh /home/pi/init.sh
User=root
[Install]
WantedBy=multi-user.target 

I tried with or without User=root, I also tried After=network.target but in any case I get the above error.

I tried using the following service file suggestef by @Ingo bellow :

[Unit]
Description=initialization script
Wants=network-online.target
After=network-online.target

[Service]
ExecStart=/bin/sh /home/pi/init.sh

[Install]
WantedBy=multi-user.target

But then I got the error:

**Αpr 23 12:41:17 raspberrypi init.sh[418]: Cannot find device "wwan0"
Apr 23 12:41:17 raspberrypi init.sh[418]: /home/pi/init.sh: 6: /home/pi/init.sh: cannot create /sys/class/net/wwan0/qmi/raw_ip: Directory nonexi
Apr 23 12:41:17 raspberrypi init.sh[418]: Cannot find device "wwan0"
Apr 23 12:41:17 raspberrypi init.sh[418]: error: couldn't create QmiDevice: Couldn't query file info: Error when getting information for file “/dev/cdc-wdm0”:**  

My assumption is that it doesn't recognize the ttyUSB on time but I don't know how to check it or fix it.

Does anyone knows what I'm doing wrong here ?

1

It seems your script needs the network connection to be complete online. So try to start your service after that target. Services are started as Type=simple with root rights by default, so you don't need that options.

[Unit]
Description=initialization script
Wants=network-online.target
After=network-online.target

[Service]
ExecStart=/bin/sh /home/pi/init.sh

[Install]
WantedBy=multi-user.target

There is only a very limited environment set when running a service, in particular there is no PATH variable set. So you must use full path names in the init.sh script, e.g. /sbin/modprobe ..., /bin/echo ..., /sbin/ip ... and so on.

3
  • Thanks for the suggestion. I tried it but I got a different error. I have updated my question with this outcome. I assume perhaps something is wrong with modprobe command and reboot.
    – dk13
    Apr 23 '20 at 9:37
  • @dk13 I have updated the answer at the end.
    – Ingo
    Apr 23 '20 at 9:53
  • I tried with /sbin/modeprobe and /bin/echo etc but get the same error as previous
    – dk13
    Apr 23 '20 at 10:14

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