It is known that the currently shipped upstream release can break WiFi on RPi-0, RPi-3B, and RPi-4B. If you use WiFi on these, it is a good idea to avoid this new package until upstream fixes the problem. Add the package to IgnorePkg in
/etc/pacman.conf.
Please do not open new threads. If you feel like discussing, use this one.
Upstream bug reports:
https://bugzilla.kernel.org/show_bug.cgi?id=211731
https://github.com/raspberrypi/linux/issues/4145
Recovery procedure:
For RPi4B make sure your system is up-to-date/raspberrypi-firmware-20210217 should fix things.
For other models a temp fix is to downgrade and wait for upstream to fix:
1. Downgrade
1a. From your cache if you have it: $this->bbcode_second_pass_code('', '# pacman -U /var/cache/pacman/pkg/linux-firmware-20201218.646f159-1-any.pkg.tar.xz')
1b. Or from here if you do not have it cached: $this->bbcode_second_pass_code('', '# pacman -U http://tardis.tiny-vps.com/aarm/packages/l/linux-firmware/linux-firmware-20201218.646f159-1-any.pkg.tar.xz')
2. Reboot
I know the Pi0 is WiFi only and the upstream release breaks your network. If headless, you need another armv6h box and a call to pacman to install to the physically removed the uSD card to recover.
$this->bbcode_second_pass_code('', '
# mount /dev/sdXY /mnt
# pacman -U /path/to/linux-firmware-20201218.646f159-1-any.pkg.tar.xz --sysroot /mnt')