Left the board running with WiFi connection and later found this at the console:
[ 9644.399139] ieee80211 phy0: cw1200_update_filtering: Update filtering failed: -110.
and an endless stream of these in dmesg log:
[10142.523864] ------------[ cut here ]------------
[10142.523925] WARNING: at /build/buildd/linux-ux500-3.3.0/drivers/staging/cw1200/bh.c:113 cw1200_bh_wakeup+0x68/0x70 [cw1200_core]()
[10142.523956] Modules linked in: cw1200_wlan(C) cw1200_core(C) mac80211 g_multi
[10142.524017] [<c0016cd4>] (unwind_backtrace+0x0/0x144) from [<c06101b4>] (dump_stack+0x20/0x24)
[10142.524017] [<c06101b4>] (dump_stack+0x20/0x24) from [<c002c994>] (warn_slowpath_common+0x5c/0x74)
[10142.524047] [<c002c994>] (warn_slowpath_common+0x5c/0x74) from [<c002c9d8>] (warn_slowpath_null+0x2c/0x34)
[10142.524078] [<c002c9d8>] (warn_slowpath_null+0x2c/0x34) from [<bf0a518c>] (cw1200_bh_wakeup+0x68/0x70 [cw1200_core])
[10142.524139] [<bf0a518c>] (cw1200_bh_wakeup+0x68/0x70 [cw1200_core]) from [<bf0a68b0>] (wsm_cmd_send+0x8c/0x2b4 [cw1200_core])
[10142.524200] [<bf0a68b0>] (wsm_cmd_send+0x8c/0x2b4 [cw1200_core]) from [<bf0a7358>] (wsm_write_mib+0xd4/0x14c [cw1200_core])
[10142.524230] [<bf0a7358>] (wsm_write_mib+0xd4/0x14c [cw1200_core]) from [<bf0aea94>] (cw1200_hw_scan+0xf4/0x2e0 [cw1200_core])
[10142.524383] [<bf0aea94>] (cw1200_hw_scan+0xf4/0x2e0 [cw1200_core]) from [<bf0265e8>] (__ieee80211_start_scan+0x144/0x2b4 [mac80211])
[10142.524536] [<bf0265e8>] (__ieee80211_start_scan+0x144/0x2b4 [mac80211]) from [<bf027164>] (ieee80211_request_scan+0x34/0x4c [mac80211])
[10142.524688] [<bf027164>] (ieee80211_request_scan+0x34/0x4c [mac80211]) from [<bf03aaec>] (ieee80211_scan+0x8c/0xa4 [mac80211])
[10142.524780] [<bf03aaec>] (ieee80211_scan+0x8c/0xa4 [mac80211]) from [<c05d7dac>] (nl80211_trigger_scan+0x444/0x534)
[10142.524810] [<c05d7dac>] (nl80211_trigger_scan+0x444/0x534) from [<c04d4630>] (genl_rcv_msg+0x1cc/0x200)
[10142.524841] [<c04d4630>] (genl_rcv_msg+0x1cc/0x200) from [<c04d3a30>] (netlink_rcv_skb+0xcc/0xe8)
[10142.524841] [<c04d3a30>] (netlink_rcv_skb+0xcc/0xe8) from [<c04d445c>] (genl_rcv+0x2c/0x34)
[10142.524871] [<c04d445c>] (genl_rcv+0x2c/0x34) from [<c04d1774>] (netlink_unicast_kernel+0x94/0xd8)
[10142.524871] [<c04d1774>] (netlink_unicast_kernel+0x94/0xd8) from [<c04d3444>] (netlink_unicast+0x14c/0x19c)
[10142.524902] [<c04d3444>] (netlink_unicast+0x14c/0x19c) from [<c04d37b8>] (netlink_sendmsg+0x274/0x2d8)
[10142.524932] [<c04d37b8>] (netlink_sendmsg+0x274/0x2d8) from [<c049da3c>] (sock_sendmsg+0xdc/0xfc)
[10142.524932] [<c049da3c>] (sock_sendmsg+0xdc/0xfc) from [<c049de2c>] (__sys_sendmsg+0x308/0x328)
[10142.524963] [<c049de2c>] (__sys_sendmsg+0x308/0x328) from [<c049fda0>] (sys_sendmsg+0x4c/0x78)
[10142.524993] [<c049fda0>] (sys_sendmsg+0x4c/0x78) from [<c000f6c0>] (ret_fast_syscall+0x0/0x30)
[10142.524993] ---[ end trace f547a81a5369a822 ]---
