BCM43142/Linux problem

There's a problem using notebook Wi-Fi card BCM43142 by Broadcom in Linux.
It sometimes rejects to connect to a network. Kernel log shows the problem:

Dec  7 19:39:56 it kernel: [10269.636717] WARNING: CPU: 0 PID: 450 at net/wireless/sme.c:790 cfg80211_roamed+0x92/0xa0 [cfg80211]()
Dec  7 19:39:56 it kernel: [10269.636718] Modules linked in: ...
Dec  7 19:39:56 it kernel: [10269.636762] CPU: 0 PID: 450 Comm: wl_event_handle Tainted: P         C O 3.14.22-std-def-alt1 #1
Dec  7 19:39:56 it kernel: [10269.636764] Hardware name: ASUSTeK COMPUTER INC. X555LN/X555LN, BIOS X555LN.308 08/06/2014

That's so unpleasant...
I was confused that unloading/reloading the module (wl) doesn't help!
Then I found that should also kill wpa_supplicant!

# modprobe -r wl ; killall wpa_supplicant  ; modprobe wl

Then it helps!
I also reported to Broadcom but still no answer...