Unable to connect using a Quectel EC25-E modem and libqmi 1.18.0

Bjørn Mork bjorn at mork.no
Tue Jun 13 07:45:44 UTC 2017

Amr Bekhit <amrbekhit at gmail.com> writes:

> I've just tried this on a regular laptop running a live USB image of
> ArchLinux (archlinux-2017.04.01-x86_64.iso). This runs kernel
> 4.10.6-1-ARCH, which as far as I can tell, uses the same drivers as 4.9 (at
> least comparing qmi_wwan). This exhibited the same issue that I faced when
> working with the modem on the Raspberry Pi:

Ouch.  Thanks a lot for taking all that trouble and test this.  So much
for my scepticism towards the RPi ;-)

> I then ran the experiment again, but this time using a live USB of
> archlinux-2017.06.01-x86_64, which runs kernel 4.11. With this kernel I
> didn't have any problem starting the network as shown below:

That is rather unexpected.  There aren't really any differences between
v4.9, v4.10 or v4.11 which should make them behave differently.  Unless
we consider stable updates.  Could this be another fallout of the bug
introduced by commit 833415a3e781 ("cdc-wdm: fix "out-of-sync" due to
missing notifications")?  If so, then the fix (revert) for this bug is
backported to v4.11.2, v4.10.17 and v4.9.29.

Does this match the kernel versions you have tested?  I.e. was the last
test with 4.11 done with v4.11.2 or later, and were the failing tests
with versions before v4.9.29 and v4.10.17?

> However, I was unable to run dhcp on the network interface and thus
> ultimately, wasn't able to connect:
> root at archiso ~ # dhcpcd $(qmicli -d /dev/cdc-wdm1 -w)
>  :(
> DUID 00:01:00:01:20:ca:f5:4f:2c:27:d7:7f:1a:83
> wwp0s29u1u1i4: IAID 3a:7c:a8:5b
> wwp0s29u1u1i4: soliciting a DHCP lease
> wwp0s29u1u1i4: soliciting an IPv6 router
> wwp0s29u1u1i4: no IPv6 Routers available
> timed out
> dhcpcd exited

Did you make sure the driver and device agreed on framing (raw-ip or
802.3)?  Check

 qmicli -d /dev/cdc-wdm1 --get-expected-data-format
 qmicli -d /dev/cdc-wdm1 --wda-get-data-format

Did you try configuring the address and routing manually?  If using
raw-ip: Are you sure the DHCP client supports it?  I know the Busybox
DHCP client works and the ISC DHCP client fails.  Unsure about the
others.  You appear to use Roy Marple's client?  I don't remember if I
tested that one with raw-ip.


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