Kernel assert failure with libqmi v1.17

[Bjørn Mork]

Tang Nguyen <tang_nguyen at yahoo.com> writes:

> Hi all,
>
>
> When I am using libqmi version 1.17,  the first time I execute qmicli command to start the network, I got below kernel assert failure.
> Even I got this failure message but my modem works pretty well. It is annoying and I'd like to remove this failure message.  
> Do you have any idea how to fix this issue.  Thank you so much.
>
> - My kernel version : 3.14.18.

v3.14 is no longer a maintained stable/longterm release.  Please
upgrade to v4.8.


> - and qmicli version
>
> qmicli 1.17.0
> Copyright (C) 2015 Aleksander Morgado
> License GPLv2+: GNU GPL version 2 or later <http://gnu.org/licenses/gpl-2.0.html>
> This is free software: you are free to change and redistribute it.
> There is NO WARRANTY, to the extent permitted by law.
>
> ===
>
>
> [  242.642490] RTNL: assertion failed at
> /usr/local/src/roxkernel.ftrace/linux-3.14.68.rr1/net/core/dev.c (1585)
> [  242.642522] CPU: 0 PID: 10019 Comm: qmicli Tainted: P           O
> 3.14-2-8360e #1 Debian 3.14.68-0.1RR9
> [  242.642532] Call Trace:
> [  242.642545] RTNL: assertion failed at

This seems to lack the stack trace, so it is pretty useless for
debugging the issue.  We know the ASSERT_RTNL is there, but we don't
know where that code was called from.

In any case, there is no RTNL handling code at all in the 3.14 version
of qmi_wwan.  It's all a part of the networking core function.  So I
suspect this is a problem which has been added in your copy of v3.14.
You wouldn't happen to have backported the raw-ip support?  There was a
fix for a missing RTNL locking as part of that: commit 6c730080e663
("net: qmi_wwan: should hold RTNL while changing netdev type").  Maybe
you forgot to include that in the backport?


Bjørn