I tried to put my wifi adapter into monitor mode. It is a ALFA AWUS036NHA with AR9271 chipset.

The Kali version is: Kali Linux RaspberryPi 2 (v1.2), 3 and 4 64-Bit, 2020.1a

All the possible interfering programs were killed before.

Result: "airmon-ng" hangs forever. Also the "ip addr" command does not work anymore (hangs as well).

Running "dmesg --follow" while that happens shows the following dump:

Code:
[  204.765359] ath: phy1: Failed to wakeup in 500us
[  204.765545] WARNING: CPU: 2 PID: 840 at drivers/net/wireless/ath/ath9k/hw.c:2276 ath9k_hw_setpower+0x5e4/0x618 [ath9k_hw]
[  204.765562] Modules linked in: hci_uart btbcm serdev bluetooth ecdh_generic arc4 ath9k_htc ath9k_common ath9k_hw ath mac80211 bcm2835_codec(C) bcm2835_v4l2(C) v4l2_mem2mem bcm2835_mmal_vchiq(C) videobuf2_dma_contig videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_common v4l2_common videodev vc_sm_cma(C) brcmfmac media brcmutil cfg80211 rfkill snd_bcm2835(C) snd_pcm snd_timer snd sdhci_iproc vchiq(C) uio_pdrv_genirq uio ip_tables x_tables ipv6
[  204.765697] CPU: 2 PID: 840 Comm: ip Tainted: G         C        4.19.93-Re4son-v8+ #1
[  204.765711] Hardware name: Raspberry Pi 3 Model B Rev 1.2 (DT)
[  204.765729] pstate: 40000005 (nZcv daif -PAN -UAO)
[  204.765799] pc : ath9k_hw_setpower+0x5e4/0x618 [ath9k_hw]
[  204.765869] lr : ath9k_hw_setpower+0x5c8/0x618 [ath9k_hw]
[  204.765883] sp : ffffff800a933090
[  204.765896] x29: ffffff800a933090 x28: 0000000000000000 
[  204.765916] x27: ffffffe7f7679080 x26: 0000000000000000 
[  204.765935] x25: ffffffe7e6d59f10 x24: ffffffe7e6df8050 
[  204.765955] x23: ffffffe7f7432048 x22: 000000000002004c 
[  204.765974] x21: ffffffe7e6df8050 x20: 0000000000000000 
[  204.765993] x19: ffffffe7e6df8000 x18: 0000000000000010 
[  204.766012] x17: 0000000000000000 x16: 0000000000000000 
[  204.766031] x15: ffffffffffffffff x14: ffffff94d954c688 
[  204.766051] x13: ffffff955963198f x12: ffffff94d9631997 
[  204.766070] x11: ffffff94d9560000 x10: ffffff800a932d10 
[  204.766089] x9 : 00000000ffffffd0 x8 : 6b6177206f742064 
[  204.766109] x7 : 656c696146203a31 x6 : ffffffe7faba59e0 
[  204.766128] x5 : ffffffe7faba59e0 x4 : 000000532184d000 
[  204.766146] x3 : 0000000000000002 x2 : ff6e9c67385d2200 
[  204.766166] x1 : ff6e9c67385d2200 x0 : 0000000000000001 
[  204.766184] Call trace:
[  204.766253]  ath9k_hw_setpower+0x5e4/0x618 [ath9k_hw]
[  204.766290]  ath9k_htc_setpower+0x38/0x58 [ath9k_htc]
[  204.766321]  ath9k_htc_start+0x6c/0x260 [ath9k_htc]
[  204.766528]  drv_start+0x44/0x1b8 [mac80211]
[  204.766697]  ieee80211_do_open+0x244/0x7e0 [mac80211]
[  204.766860]  ieee80211_open+0x4c/0x68 [mac80211]
[  204.766883]  __dev_open+0xf4/0x190
[  204.766900]  __dev_change_flags+0x15c/0x1c0
[  204.766916]  dev_change_flags+0x34/0x70
[  204.766934]  do_setlink+0x2a8/0xc38
[  204.766951]  rtnl_newlink+0x3e8/0x728
[  204.766967]  rtnetlink_rcv_msg+0x12c/0x338
[  204.766986]  netlink_rcv_skb+0x60/0x120
[  204.767002]  rtnetlink_rcv+0x28/0x38root@kali:~# uname -a
Linux kali 4.19.93-Re4son-v8+ #1 SMP PREEMPT Tue Jan 7 13:59:37 UTC 2020 aarch64 GNU/Linux

[  204.767019]  netlink_unicast+0x194/0x210
[  204.767036]  netlink_sendmsg+0x16c/0x340
[  204.767055]  sock_sendmsg+0x34/0x50
[  204.767073]  ___sys_sendmsg+0x26c/0x2a0
[  204.767090]  __sys_sendmsg+0x7c/0xd0
[  204.767108]  __arm64_sys_sendmsg+0x2c/0x38
[  204.767129]  el0_svc_common+0xa4/0x1a0
[  204.767146]  el0_svc_handler+0x38/0x78
[  204.767163]  el0_svc+0x8/0xc
[  204.767177] ---[ end trace 63e5b9b96ce51978 ]---
This is the output of "uname":

Code:
root@kali:~# uname -a
Linux kali 4.19.93-Re4son-v8+ #1 SMP PREEMPT Tue Jan 7 13:59:37 UTC 2020 aarch64 GNU/Linux
How can I diagnose this further? Thanks in advance!