I have also experience this error when i tried to build wl module with my custom kernel which has "Preemption Model" set to "Preemptible Kernel (Low-Latency Desktop)".
I have also tried to set the "Preemption Model" option to" Voluntary Kernel Preemption (Nothing)" and the wl module was built successfully . thanks Aurélien -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1156138 Title: bcmwl-kernel-source 6.20.155.1+bdcom-0ubuntu6: bcmwl kernel module failed to build [FATAL: modpost: GPL-incompatible module wl.ko uses GPL-only symbol '__rcu_read_unlock'] To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/bcmwl/+bug/1156138/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs