Wifi driver BCM43142 won’t work in Fedora 30. Here is how to solve that.

  1. Add the RPM Fusion repositories to your machine with sudo dnf install https://download1.rpmfusion.org/free/fedora/rpmfusion-free-release-$(rpm -E %fedora).noarch.rpm https://download1.rpmfusion.org/nonfree/fedora/rpmfusion-nonfree-release-$(rpm -E %fedora).noarch.rpm

  2. Update sudo dnf update.

  3. Reboot sudo dnf reboot.

  4. Install the tainted driver with sudo dnf -y install kmod-wl.

  5. Reboot again. You will see your wifi network but you will be unable to connect to it.

  6. Go here to find and download the appropriate wpa_supplicant package for your computer (for me it was wpa_supplicant-2.7-1.fc29.x86_64.rpm)

Update: rpmfind will only find packages for the latest three Fedora versions, among other rpm-based distros. I think the needed wpa_supplicant is here

How the hell do I know that this will work?

Short answer: experience.

Long answer:

Multiple users of wireless network adapters supported by the proprietary broadcom-wl driver have reported that it does not work reliably in Fedora 30. PLEASE NOTE that Fedora does not provide or support this proprietary driver; we are providing this note only as a courtesy as we are aware that many people acquire the driver from a third party and use it on Fedora.

The problem seems to be that a new feature in wpa_supplicant that was enabled in Fedora 30 confuses the broadcom-wl driver. As the driver is not open source we cannot provide a fixed version of it, and we will not disable a useful wpa-supplicant feature just to make a proprietary driver work correctly.

To help out folks with affected devices, Davide Caratti is providing unofficial rebuilds of wpa_supplicant with the feature in question disabled. You can enable his COPR repository by running sudo dnf copr enable dcaratti/wpa_supplicant, and then updating your system should install his rebuild, if it is currently up-to-date compared to the version in the official repositories. With this rebuild installed, the wireless adapter should work reliably.

(From here.)

The problem is that if we try to enable this COPR repo, it won’t work…

Update: …at least around the date this post was written… I think in Fedora 34 there were no more problems with this driver but that laptop is dead for now so I can’t say for sure.