On 21/10/2025 17:10, Adrian Chadd wrote:
hi,

Ok, let's file a PR with what you have and then dig into it a bit more!

Okay, I can / should do that.
But just now I've got a little bit lucky and got some trace.
It contains only state transitions and only for wlan0, so a lot of the picture is missing, but maybe there is something in it.

wlan0: start running, 0 vaps running
wlan0: ieee80211_start_locked: up parent ath0
wlan0: start running, 1 vaps running
       ^^^^^ these look like competing calls to ieee80211_start_locked

wlan0: ieee80211_new_state_locked:2751: starting state update INIT -> INIT 
(SCAN)
wlan0: ieee80211_new_state_locked: INIT -> SCAN (arg 0) (nrunning 0 nscanning 0)
wlan0: ieee80211_newstate_cb:2567: running state update INIT -> SCAN (1)
wlan0: ieee80211_newstate_cb: INIT -> INIT arg 0 -> SCAN arg 0
wlan0: hostap_newstate: INIT -> INIT (0)
wlan0: ieee80211_swscan_cancel_scan: called; F_SCAN=0, vap=nomatch, signal=0
wlan0: ieee80211_new_state_locked:2751: starting state update INIT -> INIT 
(SCAN)
wlan0: ieee80211_new_state_locked: INIT -> SCAN (arg 0) (nrunning 0 nscanning 0)
wlan0: ieee80211_newstate_cb:2567: running state update INIT -> SCAN (1)
wlan0: ieee80211_newstate_cb: INIT -> SCAN arg 0
wlan0: hostap_newstate: INIT -> SCAN (0)
wlan0: ieee80211_swscan_cancel_scan: called; F_SCAN=0, vap=nomatch, signal=0
wlan0: ieee80211_create_ibss: creating HOSTAP on channel 11n flags 0x00010480
wlan0: ieee80211_new_state_locked:2751: starting state update SCAN -> SCAN (RUN)
wlan0: ieee80211_new_state_locked: SCAN -> RUN (arg -1) (nrunning 0 nscanning 0)
wlan0: ieee80211_init
wlan0: start running, 1 vaps running
       ^^^^^ ieee80211_start_locked is called yet again

wlan0: ieee80211_new_state_locked:2751: starting state update SCAN -> SCAN 
(SCAN)
wlan0: ieee80211_new_state_locked: RUN -> SCAN (arg 0) (nrunning 0 nscanning 0)
wlan0: stop running, 1 vaps running
       ^^^^ ieee80211_stop_locked is called, it would clear IFF_DRV_RUNNING

wlan0: ieee80211_new_state_locked:2751: starting state update SCAN -> SCAN 
(INIT)
wlan0: ieee80211_new_state_locked: SCAN -> INIT (arg -1) (nrunning 0 nscanning 
0)
wlan0: ieee80211_swscan_cancel_scan: called; F_SCAN=0, vap=nomatch, signal=0
wlan0: down parent ath0
       ^^^^ there was only one running VAP so the driver is stopped
       vvvv state transitions continue, though
wlan0: ieee80211_newstate_cb:2567: running state update SCAN -> RUN (1)
wlan0: ieee80211_newstate_cb: SCAN -> INIT arg 0 -> RUN arg -1
wlan0: hostap_newstate: SCAN -> INIT (0)
wlan0: ieee80211_swscan_cancel_scan: called; F_SCAN=0, vap=nomatch, signal=0
wlan0: ieee80211_new_state_locked:2751: starting state update INIT -> INIT (RUN)
wlan0: ieee80211_new_state_locked: INIT -> RUN (arg -1) (nrunning 0 nscanning 0)
wlan0: ieee80211_newstate_cb:2567: running state update INIT -> SCAN (1)
wlan0: ieee80211_newstate_cb: INIT -> SCAN arg 0
wlan0: hostap_newstate: INIT -> SCAN (0)
wlan0: ieee80211_swscan_cancel_scan: called; F_SCAN=0, vap=nomatch, signal=0
wlan0: ieee80211_create_ibss: creating HOSTAP on channel 11n flags 0x00010480
wlan0: ieee80211_new_state_locked:2751: starting state update SCAN -> SCAN (RUN)
wlan0: ieee80211_new_state_locked: RUN -> RUN (arg -1) (nrunning 0 nscanning 0)
wlan0: ieee80211_newstate_cb:2567: running state update SCAN -> INIT (1)
wlan0: ieee80211_newstate_cb: SCAN -> INIT arg -1
wlan0: hostap_newstate: SCAN -> INIT (-1)
wlan0: ieee80211_swscan_cancel_scan: called; F_SCAN=0, vap=nomatch, signal=0
wlan0: ieee80211_newstate_cb:2567: running state update INIT -> RUN (1)
wlan0: ieee80211_newstate_cb: INIT -> RUN arg -1
wlan0: hostap_newstate: INIT -> RUN (-1)
wlan0: ieee80211_swscan_cancel_scan: called; F_SCAN=0, vap=nomatch, signal=0
wlan0: ieee80211_create_ibss: creating HOSTAP on channel 11n flags 0x00010480
wlan0: ieee80211_new_state_locked:2751: starting state update RUN -> RUN (RUN)
wlan0: ieee80211_new_state_locked: RUN -> RUN (arg -1) (nrunning 0 nscanning 0)
wlan0: ieee80211_newstate_cb:2567: running state update RUN -> RUN (1)
wlan0: ieee80211_newstate_cb: RUN -> RUN arg -1
wlan0: hostap_newstate: RUN -> RUN (-1)
wlan0: ieee80211_swscan_cancel_scan: called; F_SCAN=0, vap=nomatch, signal=0
wlan0: ieee80211_newstate_cb:2567: running state update RUN -> RUN (1)
wlan0: ieee80211_newstate_cb: RUN -> RUN arg -1
wlan0: hostap_newstate: RUN -> RUN (-1)
wlan0: ieee80211_swscan_cancel_scan: called; F_SCAN=0, vap=nomatch, signal=0

The VAP ends up in RUN state, but there hasn't been another ieee80211_start_locked call since the ieee80211_stop_locked call, so the interface is not RUNNING.

Now, the only thing is to figure out what hostapd and network.subr were doing with wlan0... :-)
On Tue, 21 Oct 2025 at 06:30, Andriy Gapon <[email protected] <mailto:[email protected]>> wrote:

    On 21/10/2025 16:05, Andriy Gapon wrote:
     > It seems that the problem happens because the VAP is already in
    IEEE80211_S_RUN
     > state somehow and ieee80211_start_locked is not called, obviously, in
     > SIOCSIFFLAGS handling code.

    I have this DTrace output to confirm that:

    ieee80211_ioctl:entry wlan0 cmd 0x80206910 flags 0x8902 drv flags 0 state 5
    ieee80211_ioctl:entry wlan0 cmd 0x80206910 flags 0x8903 drv flags 0 state 5

    So, the VAP state is indeed IEEE80211_S_RUN.
    But IFF_RUNNING / IFF_DRV_RUNNING is not set in either if_flags or 
if_drv_flags.

    Looks like something set the VAP state bypassing the interface state 
machinery.

    I tried to catch the state transitions with wlandebug_wlan0 in rc.conf but
    apparently that changes timing enough to mask the issue.

-- Andriy Gapon



--
Andriy Gapon

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