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[Brian Burch <1415880@xxxxxxxxxxxxxxxxxx>]

I need advice on whether I should be opening a new bug, or is it OK to
stay with this one?

On further investigation, I have noticed three things:

1. The current trusty repository bcmwl-kernel-source 6.30.223.141+bdcom-
0ubuntu2 is used on my wife's laptop. This system is not experiencing
null pointer crashes OR Scan_results errors. This evidence strongly
suggests both problems were introduced with 6.30.223.248+bdcom-0ubuntu1.

2. On checking syslog carefully, the Scan_results errors are often
associated with the system running slowly and "[TTM] Out of kernel
memory" messages being logged. The "victim" is the ATI radeon drm
driver, but I suspect the bcmwl scan errors are causing the driver to
not release kernel memory it has used for its wlan scan. Usually, I have
to reboot the system to restore normal performance. I have attached an
appropriate syslog extract. (note: when searching for these display-
related messages I hit very old bugs that were never explicitly
resolved).

3. I turned wifi off 12 hours ago and have been running the system via
its ethernet adapter (incidentally, also from Broadcom). Syslog doesn't
contain ANY "out of kernel memory" errors and system performance is back
to normal and stable.


** Attachment added: "syslog extract showing kernel memory depletion"
   https://bugs.launchpad.net/ubuntu/+source/bcmwl/+bug/1415880/+attachment/4311752/+files/bcmwl-radeon-ttm-outOfKernelMemory

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https://bugs.launchpad.net/bugs/1415880

Title:
  14e4:4365 bcmwl-kernel source: fix for null pointer crash

Status in bcmwl package in Ubuntu:
  Incomplete

Bug description:
  The bcmwl package as of now misses one patch for a bug that occurs
  with BCM43142 and possibly other broadcom chipsets that will look like
  random disconnects, poor wifi signal and kernel warnings, See also
  #1379524.

  Adding the patch is a fairly simple process:

  * put the patch file in /usr/src/bcmwl-6.30.223.248+bdcom/patches
  * add the following line to  /usr/src/bcmwl-6.30.223.248+bdcom/dkms.conf
  PATCH[7]="0014-null-pointer-crash.patch"
  * run: /usr/lib/dkms/common.postinst bcmwl 6.30.223.248+bdcom /usr/share/bcmwl x86_64 $(uname -r)

  This has fixed the issue for me. Edit: I just wanted to add that I did
  not write the patch; I merely downloaded it from a paste that was
  linked from the respective AUR package.

  ProblemType: Bug
  DistroRelease: Ubuntu 14.10
  Package: bcmwl-kernel-source 6.30.223.248+bdcom-0ubuntu1 [modified: usr/src/bcmwl-6.30.223.248+bdcom/dkms.conf]
  ProcVersionSignature: Ubuntu 3.16.0-29.39-generic 3.16.7-ckt2
  Uname: Linux 3.16.0-29-generic x86_64
  NonfreeKernelModules: wl
  ApportVersion: 2.14.7-0ubuntu8.1
  Architecture: amd64
  CurrentDesktop: LXDE
  Date: Thu Jan 29 13:15:17 2015
  InstallationDate: Installed on 2015-01-26 (3 days ago)
  InstallationMedia: Lubuntu 14.10 "Utopic Unicorn" - Release amd64 (20141022.1)
  SourcePackage: bcmwl
  UpgradeStatus: No upgrade log present (probably fresh install)

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