The system log of my TO with 3.8.1 firmware contains following kernel warnings
2017-09-23T09:21:48+02:00 warning kernel: [333786.420619] ------------[ cut here ]------------
2017-09-23T09:21:48+02:00 warning kernel: [333786.425420] WARNING: CPU: 0 PID: 0 at /home/beast/beast/workspace/omnia-stable/build_dir/target-arm_cortex-a9+vfpv3_musl-1.1.15_eabi/linux-mvebu/compat-wireless-2017-01-31/net/mac80211/tx.c:946 ieee80211_nullfunc_get+0xa28/0xf74 mac80211
2017-09-23T09:21:49+02:00 warning kernel: [333786.446956] Modules linked in: qcserial option iptable_nat ip6table_nat ath9k usb_wwan rndis_host qmi_wwan pppoe nf_nat_pptp nf_nat_ipv6 nf_nat_ipv4 nf_nat_amanda nf_conntrack_pptp nf_conntrack_ipv6 nf_conntrack_ipv4 nf_conntrack_amanda ipt_REJECT ipt_MASQUERADE ebtable_nat ebtable_filter ebtable_broute cdc_ether ath9k_common armada_thermal xt_time xt_tcpudp xt_tcpmss xt_statistic xt_state xt_socket xt_recent xt_nfacct xt_nat xt_multiport xt_mark xt_mac xt_limit xt_length xt_id xt_hl xt_helper xt_ecn xt_dscp xt_conntrack xt_connmark xt_connlimit xt_connbytes xt_comment xt_TPROXY xt_TCPMSS xt_REDIRECT xt_NFQUEUE xt_LOG xt_HL xt_DSCP xt_CT xt_CLASSIFY usbserial usbnet ts_kmp ts_fsm ts_bm thermal_sys pppox ppp_mppe ppp_async nfnetlink_queue nfnetlink_acct nf_reject_ipv4 nf_nat_tftp nf_nat_snmp_basic nf_nat_sip nf_nat_redirect nf_nat_proto_gre nf_nat_masquerade_ipv4 nf_nat_irc nf_nat_h323 nf_nat_ftp nf_log_ipv4 nf_defrag_ipv6 nf_defrag_ipv4 nf_conntrack_tftp nf_conntrack_snmp nf_conntrack_sip nf_conntrack_rtcache nf_conntrack_proto_gre nf_conntrack_netlink nf_conntrack_irc nf_conntrack_h323 nf_conntrack_ftp nf_conntrack_broadcast mvsdio iptable_raw iptable_mangle iptable_filter ipt_ECN ip_tables hwmon ebtables ebt_vlan ebt_stp ebt_redirect ebt_pkttype ebt_mark_m ebt_mark ebt_limit ebt_among ebt_802_3 crc_ccitt cdc_wdm ath9k_hw sch_teql sch_tbf sch_sfq sch_red sch_prio sch_pie sch_netem sch_htb sch_gred sch_fq sch_dsmark sch_codel em_text em_nbyte em_meta em_cmp cls_basic act_vlan act_police act_pedit act_nat act_ipt act_gact act_csum act_bpf act_skbedit act_mirred em_u32 cls_u32 cls_tcindex cls_flow cls_route cls_fw sch_hfsc sch_ingress ath10k_pci ath10k_core ath mac80211 cfg80211 compat ledtrig_usbdev ledtrig_oneshot xt_LED ledtrig_morse ledtrig_heartbeat ledtrig_gpio xt_set ip_set_list_set ip_set_hash_netiface ip_set_hash_netport ip_set_hash_netnet ip_set_hash_net ip_set_hash_netportnet ip_set_hash_mac ip_set_hash_ipportnet ip_set_hash_ipportip ip_set_hash_ipport ip_set_hash_ipmark ip_set_hash_ip ip_set_bitmap_port ip_set_bitmap_ipmac ip_set_bitmap_ip ip_set ip6t_NPT ip6t_MASQUERADE nf_nat_masquerade_ipv6 nf_nat nf_conntrack ip6t_REJECT nf_reject_ipv6 nf_log_ipv6 nf_log_common ip6table_raw ip6table_mangle ip6table_filter ip6_tables pppoatm ppp_generic slhc ip_gre gre ifb sit ip6_tunnel tunnel6 tunnel4 ip_tunnel veth tun snd_compress snd_pcm_oss snd_mixer_oss snd_pcm snd_timer snd_rawmidi snd_seq_device snd_hwdep snd input_core soundcore br2684 atm xt_NFLOG x_tables nfnetlink_log nfnetlink sha1_generic ecb xhci_plat_hcd xhci_pci xhci_hcd orion_wdt uhci_hcd ledtrig_transient usbcore nls_base usb_common mii aead crypto_null
2017-09-23T09:21:49+02:00 warning kernel: [333786.682227] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 4.4.87-cb5e816fa6b1a6b5342df69755869d71-2 #1
2017-09-23T09:21:49+02:00 warning kernel: [333786.692511] Hardware name: Marvell Armada 380/385 (Device Tree)
2017-09-23T09:21:49+02:00 warning kernel: [333786.698529] Backtrace:
2017-09-23T09:21:49+02:00 warning kernel: [333786.701082] [] (dump_backtrace) from [] (show_stack+0x18/0x1c)
2017-09-23T09:21:49+02:00 warning kernel: [333786.708754] r6:00000000 r5:60000113 r4:c06c2368 r3:00000000
2017-09-23T09:21:49+02:00 warning kernel: [333786.714555] [] (show_stack) from [] (dump_stack+0x98/0xac)
2017-09-23T09:21:49+02:00 warning kernel: [333786.721883] [] (dump_stack) from [] (warn_slowpath_common+0x8c/0xbc)
2017-09-23T09:21:49+02:00 warning kernel: [333786.730076] r6:000003b2 r5:bf3c4b74 r4:00000000 r3:00000000
2017-09-23T09:21:49+02:00 warning kernel: [333786.735878] [] (warn_slowpath_common) from [] (warn_slowpath_null+0x24/0x2c)
2017-09-23T09:21:49+02:00 warning kernel: [333786.744768] r8:c06b1608 r7:e64aa0e8 r6:00000200 r5:ec081a00 r4:0000001a
2017-09-23T09:21:49+02:00 warning kernel: [333786.751669] [] (warn_slowpath_null) from [] (ieee80211_nullfunc_get+0xa28/0xf74 [mac80211])
2017-09-23T09:21:49+02:00 warning kernel: [333786.761917] [] (ieee80211_nullfunc_get [mac80211]) from [] (ieee80211_tx_dequeue+0x2c0/0x71c [mac80211])
2017-09-23T09:21:49+02:00 warning kernel: [333786.773245] r10:ed9ccba0 r9:ec081a00 r8:e64aa0f0 r7:e64aa0e8 r6:e64aa180 r5:e64aa0e8
2017-09-23T09:21:49+02:00 warning kernel: [333786.781229] r4:e4a81a2e
2017-09-23T09:21:49+02:00 warning kernel: [333786.783892] [] (ieee80211_tx_dequeue [mac80211]) from [] (ath_assign_seq+0x364/0x5c4 [ath9k])
2017-09-23T09:21:49+02:00 warning kernel: [333786.794262] r10:e64aa194 r9:00000003 r8:ed9ccba0 r7:ed9cd5e0 r6:00000000 r5:e64aa18c
2017-09-23T09:21:49+02:00 warning kernel: [333786.802248] r4:00000001
2017-09-23T09:21:49+02:00 warning kernel: [333786.804888] [] (ath_assign_seq [ath9k]) from [] (ath_assign_seq+0x400/0x5c4 [ath9k])
2017-09-23T09:21:49+02:00 warning kernel: [333786.814475] r8:00000000 r7:00000000 r6:e64aa18c r5:ed9ce09c r4:ed9cea34
2017-09-23T09:21:49+02:00 warning kernel: [333786.821332] [] (ath_assign_seq [ath9k]) from [] (ath_txq_schedule+0x124/0x7b0 [ath9k])
2017-09-23T09:21:49+02:00 warning kernel: [333786.831093] r10:e64aa18c r9:ed9ce088 r8:c06b1760 r7:00000001 r6:ed9cea34 r5:ed9ce09c
2017-09-23T09:21:49+02:00 warning kernel: [333786.839076] r4:ed9cea34
2017-09-23T09:21:49+02:00 warning kernel: [333786.841715] [] (ath_txq_schedule [ath9k]) from [] (ath9k_wake_tx_queue+0x44/0x50 [ath9k])
2017-09-23T09:21:49+02:00 warning kernel: [333786.851737] r10:e64aa0e8 r9:ed9ccc3c r8:ed9ccc30 r7:ed9cd5e0 r6:ed9ce088 r5:ed9ce09c
2017-09-23T09:21:49+02:00 warning kernel: [333786.859720] r4:e64aa180
2017-09-23T09:21:49+02:00 warning kernel: [333786.862381] [] (ath9k_wake_tx_queue [ath9k]) from [] (ieee80211_tx_dequeue+0x690/0x71c [mac80211])
2017-09-23T09:21:49+02:00 warning kernel: [333786.873187] r7:e64aa180 r6:edb69c98 r5:ec081a00 r4:ed9ccba0
2017-09-23T09:21:49+02:00 warning kernel: [333786.879028] [] (ieee80211_tx_dequeue [mac80211]) from [] (ieee80211_tx_prepare_skb+0x1dc/0x240 [mac80211])
2017-09-23T09:21:49+02:00 warning kernel: [333786.890529] r10:ec8fa480 r9:00000000 r8:ed9ccba0 r7:000005fe r6:00000000 r5:ec8fa480
2017-09-23T09:21:49+02:00 warning kernel: [333786.898512] r4:ec081a00
2017-09-23T09:21:49+02:00 warning kernel: [333786.901191] [] (ieee80211_tx_prepare_skb [mac80211]) from [] (ieee80211_xmit+0x94/0xe8 [mac80211])
2017-09-23T09:21:49+02:00 warning kernel: [333786.911997] r9:00000000 r8:00000000 r7:edaf3000 r6:ed9ccba0 r5:ec8fa480 r4:ec081a00
2017-09-23T09:21:49+02:00 warning kernel: [333786.919940] [] (ieee80211_xmit [mac80211]) from [] (__ieee80211_subif_start_xmit+0x468/0x874 [mac80211])
2017-09-23T09:21:49+02:00 warning kernel: [333786.931268] r7:00000000 r6:ec8fa000 r5:00000000 r4:000280ca
2017-09-23T09:21:49+02:00 warning kernel: [333786.937110] [] (__ieee80211_subif_start_xmit [mac80211]) from [] (ieee80211_subif_start_xmit+0x38/0x2e0 [mac80211])
2017-09-23T09:21:49+02:00 warning kernel: [333786.949395] r10:ed317054 r9:ed317480 r8:00000000 r7:ec89ebc0 r6:e4a81a42 r5:ec8fa000
2017-09-23T09:21:49+02:00 warning kernel: [333786.957381] r4:ec081a00
2017-09-23T09:21:49+02:00 warning kernel: [333786.960040] [] (ieee80211_subif_start_xmit [mac80211]) from [] (dev_hard_start_xmit+0x238/0x338)
2017-09-23T09:21:49+02:00 warning kernel: [333786.970671] r10:ed317054 r9:ed317480 r8:00000000 r7:ec89ebc0 r6:ec8fa000 r5:ec8fa000
2017-09-23T09:21:49+02:00 warning kernel: [333786.978657] r4:ec081a00
2017-09-23T09:21:49+02:00 warning kernel: [333786.981293] [] (dev_hard_start_xmit) from [] (__dev_queue_xmit+0x434/0x540)
2017-09-23T09:21:49+02:00 warning kernel: [333786.990096] r10:ed317054 r9:ed317480 r8:00000000 r7:ec89ebc0 r6:ec8fa000 r5:c06ad4a4
2017-09-23T09:21:49+02:00 warning kernel: [333786.998082] r4:ec081a00
2017-09-23T09:21:49+02:00 warning kernel: [333787.000717] [] (__dev_queue_xmit) from [] (dev_queue_xmit+0x14/0x18)
2017-09-23T09:21:49+02:00 warning kernel: [333787.008910] r10:ed317054 r9:ed317480 r8:ed317000 r7:e4a81a42 r6:00000000 r5:ec081a00
2017-09-23T09:21:49+02:00 warning kernel: [333787.016896] r4:ec081a00
2017-09-23T09:21:49+02:00 warning kernel: [333787.019534] [] (dev_queue_xmit) from [] (br_dev_queue_push_xmit+0xf4/0x14c)
2017-09-23T09:21:49+02:00 warning kernel: [333787.028341] [] (br_dev_queue_push_xmit) from [] (br_forward_finish+0x9c/0xa4)
2017-09-23T09:21:49+02:00 warning kernel: [333787.037318] r7:e4a81a42 r6:00000000 r5:ec081a00 r4:c06d35c0
2017-09-23T09:21:49+02:00 warning kernel: [333787.043118] [] (br_forward_finish) from [] (__br_deliver+0xa0/0xa8)
2017-09-23T09:21:49+02:00 warning kernel: [333787.051224] r6:ec081a00 r5:ec081a00 r4:c06d35c0
2017-09-23T09:21:49+02:00 warning kernel: [333787.055970] [] (__br_deliver) from [] (br_deliver+0x58/0x5c)
2017-09-23T09:21:49+02:00 warning kernel: [333787.063467] r5:00000000 r4:001eb33d
2017-09-23T09:21:49+02:00 warning kernel: [333787.067156] [] (br_deliver) from [] (br_dev_xmit+0xfc/0x268)
2017-09-23T09:21:49+02:00 warning kernel: [333787.074656] [] (br_dev_xmit) from [] (dev_hard_start_xmit+0x238/0x338)
2017-09-23T09:21:49+02:00 warning kernel: [333787.083024] r9:ed317054 r8:ec2e7bc0 r7:e9a2a4c0 r6:ed317040 r5:ed317000 r4:ec081a00
2017-09-23T09:21:49+02:00 warning kernel: [333787.090925] [] (dev_hard_start_xmit) from [] (__dev_queue_xmit+0x434/0x540)
2017-09-23T09:21:49+02:00 warning kernel: [333787.099728] r10:ef3d8000 r9:00000050 r8:00000000 r7:ed9da200 r6:ed317000 r5:c06ad4a4
2017-09-23T09:21:49+02:00 warning kernel: [333787.107712] r4:ec081a00
2017-09-23T09:21:49+02:00 warning kernel: [333787.110346] [] (__dev_queue_xmit) from [] (dev_queue_xmit+0x14/0x18)
2017-09-23T09:21:49+02:00 warning kernel: [333787.118540] r10:ef3d8000 r9:00000050 r8:00000002 r7:ec081a00 r6:0000000e r5:ed0798a4
2017-09-23T09:21:49+02:00 warning kernel: [333787.126523] r4:ed079800
2017-09-23T09:21:49+02:00 warning kernel: [333787.129159] [] (dev_queue_xmit) from [] (ip_finish_output2+0x1ac/0x3a4)
2017-09-23T09:21:49+02:00 warning kernel: [333787.137616] [] (ip_finish_output2) from [] (ip_finish_output+0x134/0x21c)
2017-09-23T09:21:49+02:00 warning kernel: [333787.146246] r9:000005dc r8:00000000 r7:c06d35c0 r6:ec081a00 r5:00000000 r4:0049cb41
2017-09-23T09:21:49+02:00 warning kernel: [333787.154145] [] (ip_finish_output) from [] (ip_output+0x128/0x134)
2017-09-23T09:21:49+02:00 warning kernel: [333787.162078] r10:ef3d8000 r9:00000000 r8:ed317000 r7:c06d35c0 r6:ec081a00 r5:00000000
2017-09-23T09:21:49+02:00 warning kernel: [333787.170063] r4:0049cb41
2017-09-23T09:21:49+02:00 warning kernel: [333787.172698] [] (ip_output) from [] (ip_forward_finish+0xbc/0xcc)
2017-09-23T09:21:49+02:00 warning kernel: [333787.180544] r9:c06d35c0 r8:00000000 r7:c06d35c0 r6:ec081a00 r5:00000001 r4:7a8860dd
2017-09-23T09:21:49+02:00 warning kernel: [333787.188442] [] (ip_forward_finish) from [] (ip_forward+0x418/0x4b4)
2017-09-23T09:21:49+02:00 warning kernel: [333787.196549] r8:ec081a00 r7:e4a81a50 r6:ec081a00 r5:c06d35c0 r4:e5b35080 r3:00000000
2017-09-23T09:21:49+02:00 warning kernel: [333787.204452] [] (ip_forward) from [] (ip_rcv_finish+0x1ac/0x408)
2017-09-23T09:21:49+02:00 warning kernel: [333787.212210] r8:ec081a00 r7:00000000 r6:ec081a00 r5:c06d35c0 r4:e4a81a50
2017-09-23T09:21:49+02:00 warning kernel: [333787.219064] [] (ip_rcv_finish) from [] (ip_rcv+0x340/0x4b4)
2017-09-23T09:21:49+02:00 warning kernel: [333787.226475] r7:00000000 r6:004c468b r5:e4a81a00 r4:00000050
2017-09-23T09:21:49+02:00 warning kernel: [333787.232277] [] (ip_rcv) from [] (__netif_receive_skb_core+0x554/0x998)
2017-09-23T09:21:49+02:00 warning kernel: [333787.240645] r10:ec081ab4 r9:ef3d805c r8:00000008 r7:ef3d8000 r6:c06b4a30 r5:ef3d8048
2017-09-23T09:21:49+02:00 warning kernel: [333787.248631] r4:ec081a00
2017-09-23T09:21:49+02:00 warning kernel: [333787.251266] [] (__netif_receive_skb_core) from [] (__netif_receive_skb+0x30/0x8c)
2017-09-23T09:21:49+02:00 warning kernel: [333787.260592] r10:ef6d3470 r9:ef6d3464 r8:00000040 r7:ef6d3408 r6:00000000 r5:00000000
2017-09-23T09:21:49+02:00 warning kernel: [333787.268578] r4:ef6d3478
2017-09-23T09:21:49+02:00 warning kernel: [333787.271213] [] (__netif_receive_skb) from [] (process_backlog+0x88/0x140)
2017-09-23T09:21:49+02:00 warning kernel: [333787.279843] r4:ef6d3478 r3:ef6d3408
2017-09-23T09:21:49+02:00 warning kernel: [333787.283532] [] (process_backlog) from [] (net_rx_action+0x13c/0x308)
2017-09-23T09:21:49+02:00 warning kernel: [333787.291725] r10:01fce47a r9:c06b2100 r8:c06b1e08 r7:0000012c r6:00000040 r5:00000001
2017-09-23T09:21:49+02:00 warning kernel: [333787.299710] r4:ef6d3478 r3:c042bda8
2017-09-23T09:21:49+02:00 warning kernel: [333787.303400] [] (net_rx_action) from [] (__do_softirq+0x114/0x260)
2017-09-23T09:21:49+02:00 warning kernel: [333787.311333] r10:00000000 r9:00000003 r8:00000100 r7:c06b0000 r6:40000003 r5:c06b2080
2017-09-23T09:21:49+02:00 warning kernel: [333787.319319] r4:c06b208c
2017-09-23T09:21:49+02:00 warning kernel: [333787.321954] [] (__do_softirq) from [] (irq_exit+0x80/0xb8)
2017-09-23T09:21:49+02:00 warning kernel: [333787.329278] r10:c06b1f80 r9:f0803100 r8:ef005000 r7:00000001 r6:00000000 r5:00000000
2017-09-23T09:21:49+02:00 warning kernel: [333787.337263] r4:c06ac03c
2017-09-23T09:21:49+02:00 warning kernel: [333787.339899] [] (irq_exit) from [] (__handle_domain_irq+0x68/0xb8)
2017-09-23T09:21:49+02:00 warning kernel: [333787.347831] r4:c06ac03c r3:f0802100
2017-09-23T09:21:49+02:00 warning kernel: [333787.351522] [] (__handle_domain_irq) from [] (gic_handle_irq+0x50/0x94)
2017-09-23T09:21:49+02:00 warning kernel: [333787.359977] r8:c06b1f10 r7:f080210c r6:c06b3034 r5:c06c27bc r4:f0802100 r3:c06b1f10
2017-09-23T09:21:49+02:00 warning kernel: [333787.367877] [] (gic_handle_irq) from [] (__irq_svc+0x54/0x70)
2017-09-23T09:21:49+02:00 warning kernel: [333787.375463] Exception stack(0xc06b1f10 to 0xc06b1f58)
2017-09-23T09:21:49+02:00 warning kernel: [333787.380613] 1f00: 00000001 00000000 c06b1f70 c000b540
2017-09-23T09:21:49+02:00 warning kernel: [333787.388896] 1f20: c06b0000 c06b2498 c05bc35c 00000000 00000000 c06ad150 c06b1f80 c06b1f6c
2017-09-23T09:21:49+02:00 warning kernel: [333787.397179] 1f40: c06b1f70 c06b1f60 c0019424 c0019428 60000013 ffffffff
2017-09-23T09:21:49+02:00 warning kernel: [333787.403893] r9:c06ad150 r8:00000000 r7:c06b1f44 r6:ffffffff r5:60000013 r4:c0019428
2017-09-23T09:21:49+02:00 warning kernel: [333787.411798] [] (arch_cpu_idle) from [] (default_idle_call+0x28/0x34)
2017-09-23T09:21:49+02:00 warning kernel: [333787.419994] [] (default_idle_call) from [] (cpu_startup_entry+0x14c/0x22c)
2017-09-23T09:21:49+02:00 warning kernel: [333787.428713] [] (cpu_startup_entry) from [] (rest_init+0x80/0x84)
2017-09-23T09:21:49+02:00 warning kernel: [333787.436558] r7:c06b23c0
2017-09-23T09:21:49+02:00 warning kernel: [333787.439195] [] (rest_init) from [] (start_kernel+0x460/0x46c)
2017-09-23T09:21:49+02:00 warning kernel: [333787.446781] [] (start_kernel) from [<0000807c>] (0x807c)
2017-09-23T09:21:49+02:00 warning kernel: [333787.453096] —[ end trace 4a357372dda6a887 ]—
2017-09-23T09:21:49+02:00 warning kernel: [333787.457989] ath10k_pci 0000:02:00.0: SWBA overrun on vdev 0, skipped old beacon
2017-09-23T09:21:49+02:00 warning kernel: [333787.465432] ath10k_pci 0000:02:00.0: SWBA overrun on vdev 0, skipped old beacon
2017-09-23T09:21:49+02:00 warning kernel: [333787.472851] ath10k_pci 0000:02:00.0: SWBA overrun on vdev 0, skipped old beacon
2017-09-23T09:21:49+02:00 warning kernel: [333787.480285] ath10k_pci 0000:02:00.0: SWBA overrun on vdev 0, skipped old beacon
2017-09-23T09:21:49+02:00 warning kernel: [333787.487715] ath10k_pci 0000:02:00.0: SWBA overrun on vdev 0, skipped old beacon
2017-09-23T09:21:49+02:00 warning kernel: [333787.495142] ath10k_pci 0000:02:00.0: SWBA overrun on vdev 0, skipped old beacon
2017-09-23T09:21:49+02:00 warning kernel: [333787.502560] ath10k_pci 0000:02:00.0: SWBA overrun on vdev 0, skipped old beacon