The WiFi provided with my T560 Thinkpad Lenovo laptop regularly crashes,
especially after resume, with such traces:

[110296.376837] ------------[ cut here ]------------
[110296.376855] WARNING: CPU: 1 PID: 15294 at
../drivers/net/wireless/brcm80211/brcmfmac/core.c:1144
brcmf_netdev_wait_pend8021x+0xec/0x100 [brcmfmac]()
[110296.376857] Modules linked in: tun ipheth xt_nat xt_tcpudp veth cmac ecb
rfcomm ipt_MASQUERADE nf_nat_masquerade_ipv4 ebtable_filter iptable_nat
ebtables nf_nat_ipv4 xt_addrtype nf_nat br_netfilter bridge stp llc vmnet(O)
ppdev parport_pc parport nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack
dm_thin_pool nf_conntrack dm_persistent_data fuse dm_bio_prison dm_bufio
vmw_vsock_vmci_transport vsock nf_log_ipv4 nf_log_common xt_LOG loop xt_limit
ip6table_filter ip6_tables vmw_vmci iptable_filter ip_tables x_tables vmmon(O)
af_packet vboxpci(O) vboxnetadp(O) vboxnetflt(O) snd_hda_codec_hdmi vboxdrv(O)
bnep xfs libcrc32c snd_hda_codec_realtek snd_hda_codec_generic brcmfmac
nls_iso8859_1 brcmutil nls_cp437 vfat fat snd_hda_intel snd_hda_controller
snd_hda_codec snd_hda_core snd_hwdep uvcvideo btusb intel_rapl
[110296.376881]  videobuf2_vmalloc snd_pcm videobuf2_memops
x86_pkg_temp_thermal btbcm videobuf2_core thinkpad_acpi btintel v4l2_common
e1000e snd_timer coretemp kvm_intel videodev bluetooth kvm cfg80211 snd ptp
tpm_crb joydev ac tpm_tis soundcore pps_core mmc_core pcspkr thermal tpm rfkill
serio_raw i2c_i801 wmi battery shpchp processor efivarfs dm_crypt
hid_logitech_hidpp btrfs hid_logitech_dj usbhid xor crct10dif_pclmul
crc32_pclmul crc32c_intel aesni_intel raid6_pq aes_x86_64 glue_helper lrw
gf128mul ablk_helper cryptd xhci_pci xhci_hcd usbcore usb_common i915
i2c_algo_bit drm_kms_helper drm video button dm_mod sg
[110296.376909] CPU: 1 PID: 15294 Comm: kworker/u16:64 Tainted: G        W  O  
 4.1.26-21-default #1
[110296.376910] Hardware name: LENOVO 20FHCTO1WW/20FHCTO1WW, BIOS N1KET21W
(1.08 ) 04/20/2016
[110296.376924] Workqueue: cfg80211 cfg80211_event_work [cfg80211]
[110296.376925]  0000000000000286 0000000000000000 ffffffff8165f200
0000000000000000
[110296.376927]  0000000000000000 ffffffffa08eb6d8 ffffffff81068951
0000000000000001
[110296.376929]  ffff8800467c8840 ffff8800467c8970 0000000000000000
ffff880172996008
[110296.376931] Call Trace:
[110296.376939]  [<ffffffff810055cc>] dump_trace+0x8c/0x340
[110296.376942]  [<ffffffff8100597c>] show_stack_log_lvl+0xfc/0x1a0
[110296.376944]  [<ffffffff81006ec1>] show_stack+0x21/0x50
[110296.376947]  [<ffffffff8165f200>] dump_stack+0x5d/0x79
[110296.376950]  [<ffffffff81068951>] warn_slowpath_common+0x81/0xb0
[110296.376958]  [<ffffffffa08d55ac>] brcmf_netdev_wait_pend8021x+0xec/0x100
[brcmfmac]
[110296.376972]  [<ffffffffa08c28dc>] send_key_to_dongle+0xac/0x120 [brcmfmac]
[110296.376977]  [<ffffffffa08c2be4>] brcmf_cfg80211_del_key+0x84/0xc0
[brcmfmac]
[110296.376989]  [<ffffffffa05661ac>] __cfg80211_disconnected+0xfc/0x3e0
[cfg80211]
[110296.376999]  [<ffffffffa053ca03>] cfg80211_process_wdev_events+0x183/0x1c0
[cfg80211]
[110296.377009]  [<ffffffffa053ca78>] cfg80211_process_rdev_events+0x38/0x70
[cfg80211]
[110296.377016]  [<ffffffffa053701a>] cfg80211_event_work+0x1a/0x20 [cfg80211]
[110296.377019]  [<ffffffff81080fc5>] process_one_work+0x145/0x450
[110296.377022]  [<ffffffff810813e4>] worker_thread+0x114/0x470
[110296.377025]  [<ffffffff81086971>] kthread+0xc1/0xe0
[110296.377028]  [<ffffffff81665de2>] ret_from_fork+0x42/0x70
[110296.377030] ---[ end trace 266d56fecf357780 ]---


Extra info  :

% lspci
04:00.0 Network controller: Broadcom Corporation BCM4356 802.11ac Wireless
Network Adapter (rev 02)

% uname -a
Linux localhost 4.1.26-21-default #1 SMP PREEMPT Mon Jun 13 13:32:30 UTC 2016
(294632f) x86_64 x86_64 x86_64 GNU/Linux

Usually, restarting NetworkManager get it back, but sometimes a reboot is
necessary.