(In reply to Nerijus Baliūnas from comment #0)
> ModemManager 1.4.0-1.fc21 does not connect:
> NetworkManager[663]: <warn> (ttyUSB0) failed to connect modem: Cannot
> recover from a power off
> (NetworkManager:663): NetworkManager-wwan-CRITICAL **: modem_prepare_result:
> assertion 'state == NM_DEVICE_STATE_PREPARE' failed
> 
> If I downgrade to ModemManager-1.1.0-2.git20130913.fc20.i686, then it
> connects. After connecting I upgrade again to
> ModemManager-1.4.0-1.fc21.i686, and then it connects too.
> 
> Modem is ZTE MF628. Logs with 1.4.0 and 1.1.0 versions are attached at
> https://bugzilla.redhat.com/show_bug.cgi?id=1177256
> 
> I've checked with other versions. ModemManager-1.3.0-2.fc21.i686.rpm and
> 1.4.4-1 do not work, version 1.2.0-3 works. So the breakage happened between
> 1.2.0 and 1.3.0.

Are you able to get *debug* ModemManager logs with 1.4? Steps here:
http://www.freedesktop.org/wiki/Software/ModemManager/Debugging/

I don't really think anything was changed in the ZTE plugin between those releases, apart from maybe the QMI support, but in the non-debug logs I saw I didn't find any QMI-related thing. That's why we need the debug logs; to see if we just need to blacklist this modem like we do with the MF60 so that it doesn't use QMI.

Created attachment 113919 [details]
NetworkManager debug log

Created attachment 113920 [details]
ModemManager debug log

Debug logs attached. BTW, running /usr/sbin/NetworkManager --no-daemon --log-level=DEBUG gave no log in the console. /usr/sbin/NetworkManager --no-daemon --debug --log-level=DEBUG was needed. You may want to alter http://www.freedesktop.org/wiki/Software/ModemManager/Debugging/ page.

(In reply to Nerijus Baliūnas from comment #4)
> Debug logs attached. BTW, running /usr/sbin/NetworkManager --no-daemon
> --log-level=DEBUG gave no log in the console. /usr/sbin/NetworkManager
> --no-daemon --debug --log-level=DEBUG was needed. You may want to alter
> http://www.freedesktop.org/wiki/Software/ModemManager/Debugging/ page.

Ah, thanks, will update it.

Fixed in git master and mm-1-4:
http://cgit.freedesktop.org/ModemManager/ModemManager/commit/?id=6a8fbf917a220416913a5e64a40bd4d26c6448f5

Will go to the next stable bugfix release, thanks!

(In reply to Aleksander Morgado from comment #5)
> Ah, thanks, will update it.
Now it's (2 places):
/usr/sbin/NetworkManager --debug --log-level=DEBUG
/NetworkManager --no-daemon --log-level=DEBUG
while it should be:
[/usr/sbin]/NetworkManager --no-daemon --debug --log-level=DEBUG

(In reply to Nerijus Baliūnas from comment #7)
> (In reply to Aleksander Morgado from comment #5)
> > Ah, thanks, will update it.
> Now it's (2 places):
> /usr/sbin/NetworkManager --debug --log-level=DEBUG
> /NetworkManager --no-daemon --log-level=DEBUG
> while it should be:
> [/usr/sbin]/NetworkManager --no-daemon --debug --log-level=DEBUG


--no-daemon isn't needed when --debug is used, or am I wrong?

But you're right in that I needed to update it in two places; done now.

You are right, --no-daemon isn't needed when --debug is used.

BTW, you can add info how to get debug log output to file automatically. I used:
screen -L /usr/sbin/ModemManager --debug
it creates screenlog.0 file in the current dir.

(In reply to Nerijus Baliūnas from comment #10)
> BTW, you can add info how to get debug log output to file automatically. I
> used:
> screen -L /usr/sbin/ModemManager --debug
> it creates screenlog.0 file in the current dir.

I would prefer to avoid requiring additional programs to do that (i.e. 'screen').

Still, yes, I could add it as:
 $ /usr/sbin/ModemManager --debug >MM.log 2>&1 &
But then I'd need to explain how to kill that process and all that. Saying that doing "Ctrl+C" is enough is just quicker... :) These steps are really for people that have no idea on how to run stuff; if you knew how to use "screen" I could probably just tell you "stop both NM/MM, run them with --debug and get me debug logs" and you probably would be able to do it :)

Note also that both NM and MM allow changing log level during runtime, but I also try to avoid that because MM spits a lot of debug output and usually syslog has some limit on the rate of log writing per process...

(In reply to Aleksander Morgado from comment #11)
> Still, yes, I could add it as:
>  $ /usr/sbin/ModemManager --debug >MM.log 2>&1 &
Hmm, that's an idea. /usr/sbin/ModemManager --debug &> MM.log
is probably the simplest way (&> works from bash >=4).