Created attachment 218361 [details]
Screenshot of error popup

Good evening

I reported this issue to the good folks at Launchpad. The bug reference is #1014054 'https://bugs.launchpad.net/ubuntu/+bug/1014054'. Nicholas Skaggs at Canonical requested that I file this bug with you. 
I have removed modem manager package 'modemmanager_0.5.2.0-0ubuntu2_i386.deb' which comes with Ubuntu 12.04 and installed package 'modemmanager_0.4+git.20110124t203624.00b6cce-2ubuntu1_i386.deb' which came with Ubuntu 11.04

This is what I filed with them:
Bug Description

Good afternoon my Huawei E220 USB modem will not connect in Ubuntu 12.04LTS. I connect in Ubuntu 9.04, 10.04LTS and Windows XP SP3. Every time I try and connect in 12.04 I get this error:
modem-manager crashed with SIGSEGV in g_utf8_validate()

I have searched the internet and I have been unable to find any information on what is causing this error message, and what to do to correct it. Because of this 12.04 is not usable.

Regards
Philip

Correspondence with Nicholas
Nicholas Skaggs (nskaggs) wrote on 2012-06-19: 	#6

Since this modem is supported by the kernel since 2.6.20, and it's no longer working but used to, I would try a few things. First, grab an iso of a daily cd of quantal and see if your modem works running the live session via booting from the cd. If so, then the newer versions of modem-manager and/or the kernel fix your issue. To try and see if the kernel fixes the issue, go ahead and try running the 12.10 kernel on 12.04. Instructions are here:

http://www.theorangenotebook.com/2012/06/call-for-testing-1210-kernel-on-1204.html

If a newer kernel doesn't work, you can try installing the newer version of modem-manager from quantal.

If the livecd of quantal also fails, we can try using an older kernel and/or older version of modem-manager. Troubleshoot until you isolate the problem and then we can raise it to the applicable upstream.


Philip Gray (philipgr) wrote on 2012-06-25: 	#7

Good evening Nicolas. I have, after a bit of a battle, downloaded 12.10 Alpha. I am having the same issue in 12.10 that I am having with 12.04. I purchased a Linux User magazine that had a 12.04 live cd (beta version) and tried it. I got the same error. I then tried the 11.10 live cd and also got the same error that I was getting in 12.04 and 12.10. I then tried the 11.04 live cd and I was able to connect to the internet.

This past weekend I went to my friend who also has an E220 modem and who is running 12.04 on one of his hard drives (he is also running 10.04). He is not experiencing connection issues. I tried my modem in his 12.04 and it would not connect. We then put his SIM card in my modem and it connected. I then tried my SIM card in his modem and it would not connect.

I then put my cell phone's SIM card into both modems. Both did not connect. I have noticed that 10.04 is using modem-manager version 0.3. 11.04 is using modem-manager version 0.4. 11.10, 12.04 and 12.10 are using version 0.5.

The error message popups in versions 11.10, 12.04 and 12.10 all complain under:
SegvAnalysis
  Segfault happened at:0xb75ab3f0 <g_utf8_validate+464>: movzbl 0x0(%ebp),%eax
  PC(0xb75ab3f0)ok
  source "0x0(%ebp)" (0x00000000) not located in a known VMA region (needed readable region)!
  destination "%eax" ok

SegvReason
   reading NULL VMA

Nicolas what do you suggest I do next?

Regards
Philip

Nicholas Skaggs (nskaggs) wrote on 2012-07-03: 	#12

@Philip,
I added modemanager as being affected. After you file the bug on gnome.bugzilla.org, edit the Remote Watch attribute on modemmanger and link the URL. Be sure and describe the version of modem manager that works and the version which does not work, as well as the other details you found out in this report. Linking the bug report altogether isn't a bad idea :-)


I do not know what the Remote Watch attribute is or how to set it.

Regards
Philip