I too lost Wi-Fi after doing apt upgrade, which brought the kernel to 5.8.0.34-generic. Same "ioremap_cache" reported as above.
I found that the package for the broadcom in my Macbook Pro should be using firmware-b43-installer, not the bcmwl-kernel-source package, according to the "BROADCOM WIRELESS TABLE (Updated Oct 29, 2020)" table in this AskUbuntu answer: https://askubuntu.com/a/60395/157287 $ lspci -nn -d 14e4: |grep Network 03:00.0 Network controller [0280]: Broadcom Inc. and subsidiaries BCM4331 802.11a/b/g/n [14e4:4331] (rev 02) When I look up 14e4:4331 under the Ubuntu 20.04+ column, it says, for package name: firmware-b43-installer / linux-firmware So then I removed bcmwl-kernel-source: $ sudo apt-get purge bcmwl-kernel-source And then plugged in a USB Wi-Fi adapter and installed firmware-b43-installer (linux-firmware was already installed): $ sudo apt install firmware-b43-installer Rebooted, and was back in business! (albeit for 2.4 GHz only, not 5 GHz) Unfortunately, I wasn't so lucky with an old Lenovo E431 that had the same issue ("ioremap_cache"). $ lspci -nn -d 14e4: 04:00.0 Network controller [0280]: Broadcom Inc. and subsidiaries BCM43142 802.11b/g/n [14e4:4365] (rev 01) Which, in that table shows also to use firmware-b43-installer. But that's unrelated to this bcmwl bug, so I'll not pursue that here. -- 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/1907445 Title: bcmwl-kernel-source 6.30.223.271+bdcom-0ubuntu5: bcmwl kernel module failed to build Status in bcmwl package in Ubuntu: Confirmed Bug description: Wifi disappear on Macbook Pro 15" ProblemType: Package DistroRelease: Ubuntu 20.04 Package: bcmwl-kernel-source 6.30.223.271+bdcom-0ubuntu5 ProcVersionSignature: Ubuntu 5.8.0-32.34~20.04.1-generic 5.8.18 Uname: Linux 5.8.0-32-generic x86_64 ApportVersion: 2.20.11-0ubuntu27.14 Architecture: amd64 CasperMD5CheckResult: skip DKMSKernelVersion: 5.8.0-32-generic Date: Tue Dec 8 18:14:41 2020 DuplicateSignature: dkms:bcmwl-kernel-source:6.30.223.271+bdcom-0ubuntu5:/var/lib/dkms/bcmwl/6.30.223.271+bdcom/build/src/wl/sys/wl_linux.c:593:20: error: implicit declaration of function ‘ioremap_nocache’; did you mean ‘ioremap_cache’? [-Werror=implicit-function-declaration] InstallationDate: Installed on 2020-05-07 (215 days ago) InstallationMedia: Ubuntu 20.04 LTS "Focal Fossa" - Release amd64 (20200423) PackageVersion: 6.30.223.271+bdcom-0ubuntu5 Python3Details: /usr/bin/python3.8, Python 3.8.5, python3-minimal, 3.8.2-0ubuntu2 PythonDetails: N/A RelatedPackageVersions: dpkg 1.19.7ubuntu3 apt 2.0.3 SourcePackage: bcmwl Title: bcmwl-kernel-source 6.30.223.271+bdcom-0ubuntu5: bcmwl kernel module failed to build UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/bcmwl/+bug/1907445/+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