ath lor

[Kim Culhan]

Observed some instances of this lor:

Jul 21 16:09:49 foo kernel: lock order reversal:
Jul 21 16:09:49 foo kernel: 1st 0xffffff8001ad3948 ath0_scan_lock
(ath0_scan_lock) @ /usr/src/sys/net80211/ieee8
0211_node.c:2166
Jul 21 16:09:49 foo kernel: 2nd 0xffffff8001ad2018 ath0_com_lock
(ath0_com_lock) @ /usr/src/sys/net80211/ieee802
11_node.c:2518
Jul 21 16:09:49 foo kernel: KDB: stack backtrace:
Jul 21 16:09:49 foo kernel: db_trace_self_wrapper() at
db_trace_self_wrapper+0x37
Jul 21 16:09:49 foo kernel: kdb_backtrace() at kdb_backtrace+0x39
Jul 21 16:09:49 foo kernel: witness_checkorder() at witness_checkorder+0xca1
Jul 21 16:09:49 foo kernel: _mtx_lock_flags() at _mtx_lock_flags+0x79
Jul 21 16:09:49 foo kernel: ieee80211_node_leave() at
ieee80211_node_leave+0x97
Jul 21 16:09:49 foo kernel: ieee80211_iterate_nodes() at
ieee80211_iterate_nodes+0x89
Jul 21 16:09:49 foo kernel: setmlme_common() at setmlme_common+0x408
Jul 21 16:09:49 foo kernel: ieee80211_ioctl_setmlme() at
ieee80211_ioctl_setmlme+0x87
Jul 21 16:09:49 foo kernel: ieee80211_ioctl_set80211() at
ieee80211_ioctl_set80211+0x5b0
Jul 21 16:09:49 foo kernel: in_control() at in_control+0x234
Jul 21 16:09:49 foo kernel: ifioctl() at ifioctl+0x148c
Jul 21 16:09:49 foo kernel: kern_ioctl() at kern_ioctl+0x1dc
Jul 21 16:09:49 foo kernel: sys_ioctl() at sys_ioctl+0x12e
Jul 21 16:09:50 foo kernel: amd64_syscall() at amd64_syscall+0x25a
Jul 21 16:09:50 foo kernel: Xfast_syscall() at Xfast_syscall+0xfb
Jul 21 16:09:50 foo kernel: --- syscall (54, FreeBSD ELF64,
sys_ioctl), rip = 0x801210dfc, rsp = 0x7fffffffda78,
 rbp = 0x2a ---
Jul 21 16:09:50 foo kernel: ath0: stuck beacon; resetting (bmiss count 4)

thanks
-kim