I have a small handheld (GPD Win) which contains a BCM4356 WiFi device.
Scanning for networks works, but actually connecting doesn't. Looking at dmesg I spotted
[ 1559.185320] brcmfmac 0000:01:00.0: Direct firmware load for brcm/brcmfmac4356-pcie.txt failed with error -2
After dropping brcmfmac4356-pcie.txt from https://chromium.googlesource.com/chromiumos/third_party/linux-firmware/+/f151f016b4fe656399f199e28cabf8d658bcb52b/brcm/brcmfmac4356-pcie.txt into /lib/firmware/brcm, everything works as expected.
is there anything i can do to help fix this? would it be considered a valid fix to just copy the chromeOS file over? after all, it contains a mac address, which probably shouldn't be used for all users of that hardware out there (and i'm not sure what other hardware specifics). is there a better way? should the driver attempt to copy the file from EFIvarfs itself?
Is it functional with kernel >=4.19? BCM4356 doesn't work with recent kernels for me. Works with 4.19 and older.
I just did a fresh Arch Linux install on my GPD Win and I didn't have to do anything special to get wifi working. I don't know what fixed it, but I think we can close this bug now.