I'm experiencing troubles with my Dell Studio 1747 laptop and wifi card BCM43224 [14e4:4353] (rev 01). I'm using Xubuntu 18.04, but also had the same on Ubuntu 17.10. I'm using broadcom-sta driver but with bcmwl-kernel-source and even with open source drivers it's the same.
In general wifi works, but from time to time (once every 3-4 boots in average) there is no wifi interface - as it is not recognized by system or drivers are not loading. I tried to find any link between this situation and the behavior of the system (installing packages, updates, etc.), but I can't see any. It seems to be completely random.
Below you can find listing of the results of several commands.
08:00.0 Network controller : Broadcom Inc. and subsidiaries BCM43224 802.11a/b/g/n [14e4:4353] (rev 01)
*-network UNCLAIMED description: Network controller product: BCM43224 802.11a/b/g/n vendor: Broadcom Inc. and subsidiaries physical id: 0 bus info: pci@0000:08:00.0 version: 01 width: 64 bits clock: 33MHz capabilities: pm msi pciexpress bus_master cap_list configuration: latency=0 resources: memory:f8000000-f8003fff
[ 21.184919] wl: loading out-of-tree module taints kernel. [ 21.184925] wl: module license 'MIXED/Proprietary' taints kernel. [ 21.187747] wl: module verification failed: signature and/or required key missing - tainting kernel [ 21.191007] wl 0000:08:00.0: enabling device (0000 -> 0002) [ 21.191196] wl driver 18.104.22.1681 (r587334) failed with code 1 [ 21.191198] ERROR @wl_cfg80211_detach : [ 21.191199] NULL ndev->ieee80211ptr, unable to deref wl /etc/modprobe.d/broadcom-sta-dkms.conf blacklist b43 blacklist b43legacy blacklist b44 blacklist bcma blacklist brcm80211 blacklist brcmsmac blacklist ssb
If I try to load wl driver manually (with modprobe), nothing happens.
rfkill list all also gives no output.
Here is the link to successful and failed boot, as Michael suggested: