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["Marius B. Kotsbak" <1169117@xxxxxxxxxxxxxxxxxx>]

Maybe this should be set to WONTFIX and possibly just fix it for older
versions (12.04 LTS).

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https://bugs.launchpad.net/bugs/1169117

Title:
  REGRESSION: MBIM kernel suppport should be disabled until userspace
  support available (breaks Ericsson H5321 etc.)

Status in The Linux Kernel:
  Fix Released
Status in “linux” package in Ubuntu:
  Triaged
Status in “modemmanager” package in Ubuntu:
  Invalid
Status in “linux” package in Debian:
  Invalid

Bug description:
  "commit bd329e1 ("net: cdc_ncm: do not bind to NCM compatible MBIM devices")
      introduced a new policy, preferring MBIM for dual NCM/MBIM functions if
      the cdc_mbim driver was enabled.  This caused a regression for users
      wanting to use NCM."

  For background on this change please see Bug #1102343.

  This could be solved in different ways:
  1) Remove "cdc_mbim.ko" from packages like linux-image-extra-3.8.0-XX-YY. Easy, but makes it harder for people to experiment with MBIM and add userspace support

  2) Set the kernel parameter "prefer_mbim" to false for "cdc_ncm" module. This could be done by adding a file "/etc/modprobe.d/avoid-mbim.conf" with content:
    options cdc_ncm prefer_mbim=N

  This will allow people wanting to test MBIM easy access by removing or
  editing the file. Then the question is if this file should stay in
  modemmanager package or maybe in the kernel package? The required code
  for this option to exist seems to be in Ubuntu Raring packages in
  commit 04188f3010f64ddf2c75c3f4953eee9bdb4f5cc1.

  3) Debian has solved it by patching the kernel to reverse the default to be not to use MBIM:
  http://lists.alioth.debian.org/pipermail/kernel-svn-changes/2013-March/018852.html
  http://lists.debian.org/debian-kernel/2013/03/msg00611.html

  WORKAROUND: Add in /etc/modprobe.d/cdc_ncm.conf :
  options cdc_ncm prefer_mbim=N

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