Bernardo - I apologise for confusing you with the author of the patch - please disregard my comment!
I spent some time learning about the bcmwl patch referred to in #18 above. I tried a lot os things that frustratingly made no difference, but here is what counts as partial success:- 1. Backup the unpacked distro version of /usr/src/bcmwl-6.20.155.1+bdcom/patches/0006-add-support-for-linux-3.8.0.patch. 2. Move the new patch file to replace the original. A diff shows the patches have a lot in common, but also a lot of new conditional compile blocks that apply to the 3.8.0 kernels and alter the use of the gpl symbol. 3. sudo dkms status confirms bcmwl was already installed against my three kernels: generic, low-latency ans custom low-latency. 4. sudo dkms build bcmwl/6.20.155.1+bdcom -k 3.8.0-27-lowlatency and my custom kernel ran successfully (i.e. no failure due to invalid use of gpl symbol). 5. sudo dkms install bcmwl/6.20.155.1+bdcom -k 3.8.0-27-lowlatency passes the sanity check, installs wl.ko and rens depmod successfully. 6. /var/lib/dkms/bcmwl/kernel-3.8.0-27-lowlatency-i686/log/make.log shows the five compiles are ok, but the last stage issues the message "WARNING: "rcu_read_unlock_special" [/var/lib/dkms/bcmwl/6.20.155.1+bdcom/build/wl.ko] undefined!" before creating the wl.ko module. I don't know whether this warning is important or not - perhaps the patch is not complete? Unfortunately, when I reboot the bcmwl driver does not load. I guess there is another step I need to make (update-initramfs perhaps?) -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to bcmwl in Ubuntu. https://bugs.launchpad.net/bugs/1156138 Title: bcmwl-kernel-source fails to build on lowlatency kernel [FATAL: modpost: GPL-incompatible module wl.ko uses GPL-only symbol '__rcu_read_unlock'] Status in “bcmwl” package in Ubuntu: Confirmed Bug description: Ubuntu 13.04 ProblemType: Package DistroRelease: Ubuntu 13.04 Package: bcmwl-kernel-source 6.20.155.1+bdcom-0ubuntu6 ProcVersionSignature: Ubuntu 3.8.0-13.22-generic 3.8.3 Uname: Linux 3.8.0-13-generic i686 NonfreeKernelModules: wl ApportVersion: 2.9.1-0ubuntu1 Architecture: i386 DKMSKernelVersion: 3.8.0-12-lowlatency Date: Sat Mar 16 23:37:03 2013 InstallationDate: Installed on 2013-01-03 (72 days ago) InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Release i386 (20121017.2) MarkForUpload: True PackageVersion: 6.20.155.1+bdcom-0ubuntu6 SourcePackage: bcmwl Title: bcmwl-kernel-source 6.20.155.1+bdcom-0ubuntu6: bcmwl kernel module failed to build UpgradeStatus: Upgraded to raring on 2013-03-12 (4 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/bcmwl/+bug/1156138/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp