Re: [PATCH V3] mac80211: wowlan: suspend: Fix power save state stuck in ACTIVE caused by race between suspend and Tx packet.

[Johannes Berg <johannes@sipsolutions.net>]

On Wed, 2015-06-17 at 15:52 +0530, Krishna Chaitanya wrote:

> > I still don't like it. I also don't believe that what you're writing is
> > actually true. The only problem I can see is that it leads to higher
> > power consumption *while the system is suspended* - at resume time we
> > send a packet and thus kick the timers...
> "If" we send a packet, but until them the system will still be
> active.

But we *always* send a packet:

ieee80211_reconfig:
...
        /*
         * The sta might be in psm against the ap (e.g. because
         * this was the state before a hw restart), so we
         * explicitly send a null packet in order to make sure
         * it'll sync against the ap (and get out of psm).
         */
        if (!(local->hw.conf.flags & IEEE80211_CONF_PS)) {
                list_for_each_entry(sdata, &local->interfaces, list) {
                        if (sdata->vif.type != NL80211_IFTYPE_STATION)
                                continue;
                        if (!sdata->u.mgd.associated)
                                continue;

                        ieee80211_send_nullfunc(local, sdata, 0);
                }
        }



Then again, you're talking about WoWLAN, but then ...

johannes