On OpenWRT 19.07.7, I installed "umbim" (command line tool for controlling mobile broadband modems). I have a "sierra em7355" (vid:pid : 413c:81a9 , Gobi5000 / Qualcomm MDM 9615 chipset). Using a "google fi" SIM card.
"umbim -d /dev/cdc-wdm0 caps" looks good ("hardwareinfo: EM7355", etc)
I set the config :
network.wwan.ifname='wwan0'
network.wwan.proto='mbim'
network.wwan.device='/dev/cdc-wdm0'
network.wwan.apn='h2g2'
... but when I do "ifup wwan", it says :
daemon.notice netifd: wwan (6652): mbim[6652] Checking pin
daemon.notice netifd: wwan (6652): required pin: 3 - pin2
daemon.notice netifd: wwan (6652): remaining attempts: 10
daemon.notice netifd: wwan (6652): mbim[6652] PIN required
... so I modified /lib/netifd/proto/mbim.sh and commented out the "return" after "umbim pinstate" and when I did "ifup wwan" it works fine.
So ... is this a bug or should I put something in network.wwan.pincode to fix this ?
FYI, it works fine in Fedora.