2 * Off-channel operation helpers
4 * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
5 * Copyright 2004, Instant802 Networks, Inc.
6 * Copyright 2005, Devicescape Software, Inc.
7 * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
8 * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
9 * Copyright 2009 Johannes Berg <johannes@sipsolutions.net>
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
15 #include <linux/export.h>
16 #include <net/mac80211.h>
17 #include "ieee80211_i.h"
18 #include "driver-ops.h"
21 * Tell our hardware to disable PS.
22 * Optionally inform AP that we will go to sleep so that it will buffer
23 * the frames while we are doing off-channel work. This is optional
24 * because we *may* be doing work on-operating channel, and want our
25 * hardware unconditionally awake, but still let the AP send us normal frames.
27 static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata)
29 struct ieee80211_local *local = sdata->local;
30 struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
32 local->offchannel_ps_enabled = false;
34 /* FIXME: what to do when local->pspolling is true? */
36 del_timer_sync(&local->dynamic_ps_timer);
37 del_timer_sync(&ifmgd->bcn_mon_timer);
38 del_timer_sync(&ifmgd->conn_mon_timer);
40 cancel_work_sync(&local->dynamic_ps_enable_work);
42 if (local->hw.conf.flags & IEEE80211_CONF_PS) {
43 local->offchannel_ps_enabled = true;
44 local->hw.conf.flags &= ~IEEE80211_CONF_PS;
45 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
48 if (!local->offchannel_ps_enabled ||
49 !(local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK))
51 * If power save was enabled, no need to send a nullfunc
52 * frame because AP knows that we are sleeping. But if the
53 * hardware is creating the nullfunc frame for power save
54 * status (ie. IEEE80211_HW_PS_NULLFUNC_STACK is not
55 * enabled) and power save was enabled, the firmware just
56 * sent a null frame with power save disabled. So we need
57 * to send a new nullfunc frame to inform the AP that we
60 ieee80211_send_nullfunc(local, sdata, 1);
63 /* inform AP that we are awake again, unless power save is enabled */
64 static void ieee80211_offchannel_ps_disable(struct ieee80211_sub_if_data *sdata)
66 struct ieee80211_local *local = sdata->local;
69 ieee80211_send_nullfunc(local, sdata, 0);
70 else if (local->offchannel_ps_enabled) {
72 * In !IEEE80211_HW_PS_NULLFUNC_STACK case the hardware
73 * will send a nullfunc frame with the powersave bit set
74 * even though the AP already knows that we are sleeping.
75 * This could be avoided by sending a null frame with power
76 * save bit disabled before enabling the power save, but
77 * this doesn't gain anything.
79 * When IEEE80211_HW_PS_NULLFUNC_STACK is enabled, no need
80 * to send a nullfunc frame because AP already knows that
81 * we are sleeping, let's just enable power save mode in
84 /* TODO: Only set hardware if CONF_PS changed?
85 * TODO: Should we set offchannel_ps_enabled to false?
87 local->hw.conf.flags |= IEEE80211_CONF_PS;
88 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
89 } else if (local->hw.conf.dynamic_ps_timeout > 0) {
91 * If IEEE80211_CONF_PS was not set and the dynamic_ps_timer
92 * had been running before leaving the operating channel,
93 * restart the timer now and send a nullfunc frame to inform
94 * the AP that we are awake.
96 ieee80211_send_nullfunc(local, sdata, 0);
97 mod_timer(&local->dynamic_ps_timer, jiffies +
98 msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
101 ieee80211_sta_reset_beacon_monitor(sdata);
102 ieee80211_sta_reset_conn_monitor(sdata);
105 void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local,
106 bool offchannel_ps_enable)
108 struct ieee80211_sub_if_data *sdata;
111 * notify the AP about us leaving the channel and stop all
114 mutex_lock(&local->iflist_mtx);
115 list_for_each_entry(sdata, &local->interfaces, list) {
116 if (!ieee80211_sdata_running(sdata))
119 if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
120 set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
122 /* Check to see if we should disable beaconing. */
123 if (sdata->vif.type == NL80211_IFTYPE_AP ||
124 sdata->vif.type == NL80211_IFTYPE_ADHOC ||
125 sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
126 ieee80211_bss_info_change_notify(
127 sdata, BSS_CHANGED_BEACON_ENABLED);
129 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) {
130 netif_tx_stop_all_queues(sdata->dev);
131 if (offchannel_ps_enable &&
132 (sdata->vif.type == NL80211_IFTYPE_STATION) &&
133 sdata->u.mgd.associated)
134 ieee80211_offchannel_ps_enable(sdata);
137 mutex_unlock(&local->iflist_mtx);
140 void ieee80211_offchannel_return(struct ieee80211_local *local,
141 bool offchannel_ps_disable)
143 struct ieee80211_sub_if_data *sdata;
145 mutex_lock(&local->iflist_mtx);
146 list_for_each_entry(sdata, &local->interfaces, list) {
147 if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
148 clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
150 if (!ieee80211_sdata_running(sdata))
153 /* Tell AP we're back */
154 if (offchannel_ps_disable &&
155 sdata->vif.type == NL80211_IFTYPE_STATION) {
156 if (sdata->u.mgd.associated)
157 ieee80211_offchannel_ps_disable(sdata);
160 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) {
162 * This may wake up queues even though the driver
163 * currently has them stopped. This is not very
164 * likely, since the driver won't have gotten any
165 * (or hardly any) new packets while we weren't
166 * on the right channel, and even if it happens
167 * it will at most lead to queueing up one more
168 * packet per queue in mac80211 rather than on
169 * the interface qdisc.
171 netif_tx_wake_all_queues(sdata->dev);
174 if (sdata->vif.type == NL80211_IFTYPE_AP ||
175 sdata->vif.type == NL80211_IFTYPE_ADHOC ||
176 sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
177 ieee80211_bss_info_change_notify(
178 sdata, BSS_CHANGED_BEACON_ENABLED);
180 mutex_unlock(&local->iflist_mtx);
183 void ieee80211_handle_roc_started(struct ieee80211_roc_work *roc)
188 if (roc->mgmt_tx_cookie) {
189 if (!WARN_ON(!roc->frame)) {
190 ieee80211_tx_skb(roc->sdata, roc->frame);
194 cfg80211_ready_on_channel(&roc->sdata->wdev, (unsigned long)roc,
195 roc->chan, roc->chan_type,
196 roc->req_duration, GFP_KERNEL);
199 roc->notified = true;
202 static void ieee80211_hw_roc_start(struct work_struct *work)
204 struct ieee80211_local *local =
205 container_of(work, struct ieee80211_local, hw_roc_start);
206 struct ieee80211_roc_work *roc, *dep, *tmp;
208 mutex_lock(&local->mtx);
210 if (list_empty(&local->roc_list))
213 roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
219 roc->hw_begun = true;
220 roc->hw_start_time = local->hw_roc_start_time;
222 ieee80211_handle_roc_started(roc);
223 list_for_each_entry_safe(dep, tmp, &roc->dependents, list) {
224 ieee80211_handle_roc_started(dep);
226 if (dep->duration > roc->duration) {
227 u32 dur = dep->duration;
228 dep->duration = dur - roc->duration;
230 list_del(&dep->list);
231 list_add(&dep->list, &roc->list);
235 mutex_unlock(&local->mtx);
238 void ieee80211_ready_on_channel(struct ieee80211_hw *hw)
240 struct ieee80211_local *local = hw_to_local(hw);
242 local->hw_roc_start_time = jiffies;
244 trace_api_ready_on_channel(local);
246 ieee80211_queue_work(hw, &local->hw_roc_start);
248 EXPORT_SYMBOL_GPL(ieee80211_ready_on_channel);
250 void ieee80211_start_next_roc(struct ieee80211_local *local)
252 struct ieee80211_roc_work *roc;
254 lockdep_assert_held(&local->mtx);
256 if (list_empty(&local->roc_list)) {
257 ieee80211_run_deferred_scan(local);
261 roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
264 if (WARN_ON_ONCE(roc->started))
267 if (local->ops->remain_on_channel) {
268 int ret, duration = roc->duration;
270 /* XXX: duplicated, see ieee80211_start_roc_work() */
274 ret = drv_remain_on_channel(local, roc->chan,
281 wiphy_warn(local->hw.wiphy,
282 "failed to start next HW ROC (%d)\n", ret);
284 * queue the work struct again to avoid recursion
285 * when multiple failures occur
287 ieee80211_remain_on_channel_expired(&local->hw);
291 ieee80211_queue_delayed_work(&local->hw, &roc->work,
292 round_jiffies_relative(HZ/2));
296 void ieee80211_roc_notify_destroy(struct ieee80211_roc_work *roc)
298 struct ieee80211_roc_work *dep, *tmp;
300 /* was never transmitted */
302 cfg80211_mgmt_tx_status(&roc->sdata->wdev,
303 (unsigned long)roc->frame,
304 roc->frame->data, roc->frame->len,
306 kfree_skb(roc->frame);
309 if (!roc->mgmt_tx_cookie)
310 cfg80211_remain_on_channel_expired(&roc->sdata->wdev,
312 roc->chan, roc->chan_type,
315 list_for_each_entry_safe(dep, tmp, &roc->dependents, list)
316 ieee80211_roc_notify_destroy(dep);
321 void ieee80211_sw_roc_work(struct work_struct *work)
323 struct ieee80211_roc_work *roc =
324 container_of(work, struct ieee80211_roc_work, work.work);
325 struct ieee80211_sub_if_data *sdata = roc->sdata;
326 struct ieee80211_local *local = sdata->local;
329 mutex_lock(&local->mtx);
334 if (WARN_ON(list_empty(&local->roc_list)))
337 if (WARN_ON(roc != list_first_entry(&local->roc_list,
338 struct ieee80211_roc_work,
343 struct ieee80211_roc_work *dep;
347 /* switch channel etc */
348 ieee80211_recalc_idle(local);
350 local->tmp_channel = roc->chan;
351 local->tmp_channel_type = roc->chan_type;
352 ieee80211_hw_config(local, 0);
354 /* tell userspace or send frame */
355 ieee80211_handle_roc_started(roc);
356 list_for_each_entry(dep, &roc->dependents, list)
357 ieee80211_handle_roc_started(dep);
359 /* if it was pure TX, just finish right away */
364 ieee80211_queue_delayed_work(&local->hw, &roc->work,
365 msecs_to_jiffies(roc->duration));
367 /* finish this ROC */
369 list_del(&roc->list);
370 started = roc->started;
371 ieee80211_roc_notify_destroy(roc);
374 drv_flush(local, false);
376 local->tmp_channel = NULL;
377 ieee80211_hw_config(local, 0);
379 ieee80211_offchannel_return(local, true);
382 ieee80211_recalc_idle(local);
385 ieee80211_start_next_roc(local);
389 mutex_unlock(&local->mtx);
392 static void ieee80211_hw_roc_done(struct work_struct *work)
394 struct ieee80211_local *local =
395 container_of(work, struct ieee80211_local, hw_roc_done);
396 struct ieee80211_roc_work *roc;
398 mutex_lock(&local->mtx);
400 if (list_empty(&local->roc_list))
403 roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
409 list_del(&roc->list);
411 ieee80211_roc_notify_destroy(roc);
413 /* if there's another roc, start it now */
414 ieee80211_start_next_roc(local);
417 mutex_unlock(&local->mtx);
420 void ieee80211_remain_on_channel_expired(struct ieee80211_hw *hw)
422 struct ieee80211_local *local = hw_to_local(hw);
424 trace_api_remain_on_channel_expired(local);
426 ieee80211_queue_work(hw, &local->hw_roc_done);
428 EXPORT_SYMBOL_GPL(ieee80211_remain_on_channel_expired);
430 void ieee80211_roc_setup(struct ieee80211_local *local)
432 INIT_WORK(&local->hw_roc_start, ieee80211_hw_roc_start);
433 INIT_WORK(&local->hw_roc_done, ieee80211_hw_roc_done);
434 INIT_LIST_HEAD(&local->roc_list);
437 void ieee80211_roc_purge(struct ieee80211_sub_if_data *sdata)
439 struct ieee80211_local *local = sdata->local;
440 struct ieee80211_roc_work *roc, *tmp;
443 mutex_lock(&local->mtx);
444 list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
445 if (roc->sdata != sdata)
448 if (roc->started && local->ops->remain_on_channel) {
449 /* can race, so ignore return value */
450 drv_cancel_remain_on_channel(local);
453 list_move_tail(&roc->list, &tmp_list);
457 ieee80211_start_next_roc(local);
458 mutex_unlock(&local->mtx);
460 list_for_each_entry_safe(roc, tmp, &tmp_list, list) {
461 if (local->ops->remain_on_channel) {
462 list_del(&roc->list);
463 ieee80211_roc_notify_destroy(roc);
465 ieee80211_queue_delayed_work(&local->hw, &roc->work, 0);
467 /* work will clean up etc */
468 flush_delayed_work(&roc->work);
472 WARN_ON_ONCE(!list_empty(&tmp_list));