[patch] iwi(4) suspend/resume broken

[Mitsuru IWASAKI]

Hi, thanks for comments.

> Hmm, I'm not sure I like this direct, unconditional fiddling with a
> VAP's state in the stop function, have you made sure that there are no
> side effects? eg. in case no VAP exists? I remember running into issue
> while doing that on iwn(4) and it helped to not have any knowledge
> about ic or vap in either init() or stop(). Well, I've settled for

I don't warry about sc_ifp->if_l2com, because it is allocated at
attach(), but there is not guarantee that sc_ifp->if_l2com->ic_vaps is
allocated, as you pointed out.

Updated patches at:
http://people.freebsd.org/~iwasaki/wlan/ipw-20120316.diff
http://people.freebsd.org/~iwasaki/wlan/iww-20120316.diff
http://people.freebsd.org/~iwasaki/wlan/wpi-20120316.diff

> about ic or vap in either init() or stop(). Well, I've settled for
> ieee80211_stop() and ieee80211_start() in suspend/resume, which seems
> to work.

I was thinking so too, but ieee80211_stop()/ieee80211_init() are never
called from suspend/resume.  
Also wpa_supplicant(8) seems to set roaming mode to manual, so
ieee80211 state doesn't change in this case.
That's why iwi(4) suspend/resume is broken, I think.

ieee80211_proto.c:ieee80211_start_locked()
----
         /*
          * If the parent is up and running, then kick the
          * 802.11 state machine as appropriate.
          */
         if ((parent->if_drv_flags & IFF_DRV_RUNNING) &&
             vap->iv_roaming != IEEE80211_ROAMING_MANUAL) {
                  if (vap->iv_opmode == IEEE80211_M_STA) {
#if 0
                           /* XXX bypasses scan too easily; disable for now */
                           /*
                            * Try to be intelligent about clocking the state
                            * machine.  If we're currently in RUN state then
                            * we should be able to apply any new state/parameters
                            * simply by re-associating.  Otherwise we need to
                            * re-scan to select an appropriate ap.
                            */
                           if (vap->iv_state >= IEEE80211_S_RUN)
                                    ieee80211_new_state_locked(vap,
                                        IEEE80211_S_ASSOC, 1);
                           else
#endif
                                    ieee80211_new_state_locked(vap,
                                        IEEE80211_S_SCAN, 0);
                  } else {
                           /*
                            * For monitor+wds mode there's nothing to do but
                            * start running.  Otherwise if this is the first
                            * vap to be brought up, start a scan which may be
                            * preempted if the station is locked to a particular
                            * channel.
                            */
                           vap->iv_flags_ext |= IEEE80211_FEXT_REINIT;
                           if (vap->iv_opmode == IEEE80211_M_MONITOR ||
                               vap->iv_opmode == IEEE80211_M_WDS)
                                    ieee80211_new_state_locked(vap,
                                        IEEE80211_S_RUN, -1);
                           else
                                    ieee80211_new_state_locked(vap,
                                        IEEE80211_S_SCAN, 0);
                  }
         }
}
----

Should we call ieee80211_stop()/ieee80211_init() from suspend/resume
and fix above code?
I prefer calling ieee80211_new_state(IEEE80211_S_INIT) in
iwi_stop_locked() because it's equivalent to RELENG_7's
behavior and fix iwi_restart() too.

Thanks!