Scince i updated from 4.9.79-1-#ARCH to 4.14.20-1-#ARCH i experience difficulties with the wlan-device on my Raspberry Pi Model 3B v1.2. The device didn't connect at boot and any attempt to establish a wireless connection was futile. After every full system upgrade i had to downgrade the kernel back to 4.9.79 to make it work again.

Now i decided to set up the latest version of Archlinux-arm all new but the device doesn't work and i have no idea where to start troubleshooting.

What i have so far:

- all devices (eth0, wlan0 and lo) are in /sys/class/net

- ip link shows the device as <NO-CARRIER,BROADCAST,MULTICAST, UP> state: DOWN

- setting wlan0 up with ip link seems to have no result

- Surprisingly i just successfully startet wpa_supplicant but until now when i tried to start wpa_supplicant i got an error message(wlan0 is not ready and brcmfmac: power management disabled)

- netctl is disabled, systemd-networkd is loaded and running but in /etc/systemd/network/ there only one profile for eth0 and nothing for wlan0. I wrote a minimal network profile manually but without effect.

- i can scan for networks with wifi-menu but the connection fais

- wpa_cli fails with (could not connect to wpa_supplicant)

it is possible to go back to the 4.9 LTS kernel (which is still supported afaics). not sure about arch arm, but mainly arch has it in AUR.

Thanks for the Answer, going back to 7.9 installation seems a weird solution. So there are no practical values with this issue? Could it be that it has something to do with power supply?

I am confused again. Yesterday i suddenly could easily get wifi to work using wpa_supplicant+wpa_passphrase. The first thing i did was a full system upgrade to 4-14-27-1. Now there seems to be a feature that informs about powersupply and i get repeatedly information:

However the wlan device seems not to be working. When i run

i get

Is there a way to power down any other components? I intend to access the device wia ssh as soon as network configuration is finished so i e.g. could turn off tvservice but right now i need:

1 USB slot for keyboard
HDMI-Output (just for command line)
eth0
wlan0

I am thinking about a way to power down other devices