Hi,
I saw this line on some Sony laptop using a bcm4324 for wifi:
brcmfmac: brcmf_sdio_drivestrengthinit: No SDIO Drive strength init done
for chip 4324 rev 5 pmurev 17
This was with an older kernel version, but the code does not look like
it is fixed now. Wifi still worked even with this warning.
This was a device from the normal German retail market shipped with some
Windows version, but I do not have access to this device any more.
Hauke