RPI4B4G doesn't work on 64 bits rpi-5.4.y kernel.

[jfclere]

About 6 months ago the brcmfmac43455-sdio.txt and brcmfmac43455-sdio.bin where working for RPI4B4G
now there are the following error:
+++
[root@pc-81 ~]# dmesg | grep mac
[ 0.000000] Kernel command line: coherent_pool=1M 8250.nr_uarts=0 snd_bcm2835.enable_compat_alsa=0 snd_bcm2835.enable_hdmi=1 snd_bcm2835.enable_headphones=1 bcm2708_fb.fbwidth=1824 bcm2708_fb.fbheight=984 bcm2708_fb.fbswap=1 smsc95xx.macaddr=DC:A6:32:04:9C:31 vc_mem.mem_base=0x3ec00000 vc_mem.mem_size=0x40000000 wc_otg.lpm_enable=0 console=ttyS0,115200 console=tty1 root=/dev/mmcblk0p3 elevator=deadline rootfstype=ext4 fsck.repair=yes rootwait
[ 0.244138] bcm2835-dma fe007000.dma: DMA legacy API manager, dmachans=0x1
[ 1.210285] unimac-mdio unimac-mdio.-19: Broadcom UniMAC MDIO bus
[ 9.812769] brcmfmac: F1 signature read @0x18000000=0x15264345
[ 9.824223] brcmfmac: brcmf_fw_alloc_request: using brcm/brcmfmac43455-sdio for chip BCM4345/6
[ 9.848717] usbcore: registered new interface driver brcmfmac
[ 9.867124] brcmfmac mmc1:0001:1: Direct firmware load for brcm/brcmfmac43455-sdio.raspberrypi,4-model-b.txt failed with error -2
[ 10.132587] brcmfmac: brcmf_fw_alloc_request: using brcm/brcmfmac43455-sdio for chip BCM4345/6
[ 10.198406] brcmfmac: brcmf_sdio_firmware_callback: brcmf_attach failed
+++

[jfclere]

restoring old brcmfmac43455-sdio.txt and brcmfmac43455-sdio.bin fixed the problem...

[jfclere]

Note the actual firmware does NOT work with the old rpi-4.19.y kernels, old firmware does.