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-trace.h"
19 #include "driver-ops.h"
22 * Tell our hardware to disable PS.
23 * Optionally inform AP that we will go to sleep so that it will buffer
24 * the frames while we are doing off-channel work. This is optional
25 * because we *may* be doing work on-operating channel, and want our
26 * hardware unconditionally awake, but still let the AP send us normal frames.
28 static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata)
30 struct ieee80211_local *local = sdata->local;
31 struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
33 local->offchannel_ps_enabled = false;
35 /* FIXME: what to do when local->pspolling is true? */
37 del_timer_sync(&local->dynamic_ps_timer);
38 del_timer_sync(&ifmgd->bcn_mon_timer);
39 del_timer_sync(&ifmgd->conn_mon_timer);
41 cancel_work_sync(&local->dynamic_ps_enable_work);
43 if (local->hw.conf.flags & IEEE80211_CONF_PS) {
44 local->offchannel_ps_enabled = true;
45 local->hw.conf.flags &= ~IEEE80211_CONF_PS;
46 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
49 if (!local->offchannel_ps_enabled ||
50 !(local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK))
52 * If power save was enabled, no need to send a nullfunc
53 * frame because AP knows that we are sleeping. But if the
54 * hardware is creating the nullfunc frame for power save
55 * status (ie. IEEE80211_HW_PS_NULLFUNC_STACK is not
56 * enabled) and power save was enabled, the firmware just
57 * sent a null frame with power save disabled. So we need
58 * to send a new nullfunc frame to inform the AP that we
61 ieee80211_send_nullfunc(local, sdata, 1);
64 /* inform AP that we are awake again, unless power save is enabled */
65 static void ieee80211_offchannel_ps_disable(struct ieee80211_sub_if_data *sdata)
67 struct ieee80211_local *local = sdata->local;
70 ieee80211_send_nullfunc(local, sdata, 0);
71 else if (local->offchannel_ps_enabled) {
73 * In !IEEE80211_HW_PS_NULLFUNC_STACK case the hardware
74 * will send a nullfunc frame with the powersave bit set
75 * even though the AP already knows that we are sleeping.
76 * This could be avoided by sending a null frame with power
77 * save bit disabled before enabling the power save, but
78 * this doesn't gain anything.
80 * When IEEE80211_HW_PS_NULLFUNC_STACK is enabled, no need
81 * to send a nullfunc frame because AP already knows that
82 * we are sleeping, let's just enable power save mode in
85 /* TODO: Only set hardware if CONF_PS changed?
86 * TODO: Should we set offchannel_ps_enabled to false?
88 local->hw.conf.flags |= IEEE80211_CONF_PS;
89 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
90 } else if (local->hw.conf.dynamic_ps_timeout > 0) {
92 * If IEEE80211_CONF_PS was not set and the dynamic_ps_timer
93 * had been running before leaving the operating channel,
94 * restart the timer now and send a nullfunc frame to inform
95 * the AP that we are awake.
97 ieee80211_send_nullfunc(local, sdata, 0);
98 mod_timer(&local->dynamic_ps_timer, jiffies +
99 msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
102 ieee80211_sta_reset_beacon_monitor(sdata);
103 ieee80211_sta_reset_conn_monitor(sdata);
106 void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local,
107 bool offchannel_ps_enable)
109 struct ieee80211_sub_if_data *sdata;
112 * notify the AP about us leaving the channel and stop all
115 mutex_lock(&local->iflist_mtx);
116 list_for_each_entry(sdata, &local->interfaces, list) {
117 if (!ieee80211_sdata_running(sdata))
120 if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
121 set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
123 /* Check to see if we should disable beaconing. */
124 if (sdata->vif.type == NL80211_IFTYPE_AP ||
125 sdata->vif.type == NL80211_IFTYPE_ADHOC ||
126 sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
127 ieee80211_bss_info_change_notify(
128 sdata, BSS_CHANGED_BEACON_ENABLED);
130 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) {
131 netif_tx_stop_all_queues(sdata->dev);
132 if (offchannel_ps_enable &&
133 (sdata->vif.type == NL80211_IFTYPE_STATION) &&
134 sdata->u.mgd.associated)
135 ieee80211_offchannel_ps_enable(sdata);
138 mutex_unlock(&local->iflist_mtx);
141 void ieee80211_offchannel_return(struct ieee80211_local *local,
142 bool offchannel_ps_disable)
144 struct ieee80211_sub_if_data *sdata;
146 mutex_lock(&local->iflist_mtx);
147 list_for_each_entry(sdata, &local->interfaces, list) {
148 if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
149 clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
151 if (!ieee80211_sdata_running(sdata))
154 /* Tell AP we're back */
155 if (offchannel_ps_disable &&
156 sdata->vif.type == NL80211_IFTYPE_STATION) {
157 if (sdata->u.mgd.associated)
158 ieee80211_offchannel_ps_disable(sdata);
161 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) {
163 * This may wake up queues even though the driver
164 * currently has them stopped. This is not very
165 * likely, since the driver won't have gotten any
166 * (or hardly any) new packets while we weren't
167 * on the right channel, and even if it happens
168 * it will at most lead to queueing up one more
169 * packet per queue in mac80211 rather than on
170 * the interface qdisc.
172 netif_tx_wake_all_queues(sdata->dev);
175 if (sdata->vif.type == NL80211_IFTYPE_AP ||
176 sdata->vif.type == NL80211_IFTYPE_ADHOC ||
177 sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
178 ieee80211_bss_info_change_notify(
179 sdata, BSS_CHANGED_BEACON_ENABLED);
181 mutex_unlock(&local->iflist_mtx);
184 void ieee80211_handle_roc_started(struct ieee80211_roc_work *roc)
189 if (roc->mgmt_tx_cookie) {
190 if (!WARN_ON(!roc->frame)) {
191 ieee80211_tx_skb(roc->sdata, roc->frame);
195 cfg80211_ready_on_channel(roc->sdata->dev, (unsigned long)roc,
196 roc->chan, roc->chan_type,
197 roc->req_duration, GFP_KERNEL);
200 roc->notified = true;
203 static void ieee80211_hw_roc_start(struct work_struct *work)
205 struct ieee80211_local *local =
206 container_of(work, struct ieee80211_local, hw_roc_start);
207 struct ieee80211_roc_work *roc, *dep, *tmp;
209 mutex_lock(&local->mtx);
211 if (list_empty(&local->roc_list))
214 roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
220 roc->hw_begun = true;
221 roc->hw_start_time = local->hw_roc_start_time;
223 ieee80211_handle_roc_started(roc);
224 list_for_each_entry_safe(dep, tmp, &roc->dependents, list) {
225 ieee80211_handle_roc_started(dep);
227 if (dep->duration > roc->duration) {
228 u32 dur = dep->duration;
229 dep->duration = dur - roc->duration;
231 list_del(&dep->list);
232 list_add(&dep->list, &roc->list);
236 mutex_unlock(&local->mtx);
239 void ieee80211_ready_on_channel(struct ieee80211_hw *hw)
241 struct ieee80211_local *local = hw_to_local(hw);
243 local->hw_roc_start_time = jiffies;
245 trace_api_ready_on_channel(local);
247 ieee80211_queue_work(hw, &local->hw_roc_start);
249 EXPORT_SYMBOL_GPL(ieee80211_ready_on_channel);
251 void ieee80211_start_next_roc(struct ieee80211_local *local)
253 struct ieee80211_roc_work *roc;
255 lockdep_assert_held(&local->mtx);
257 if (list_empty(&local->roc_list)) {
258 ieee80211_run_deferred_scan(local);
262 roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
265 if (local->ops->remain_on_channel) {
266 int ret, duration = roc->duration;
268 /* XXX: duplicated, see ieee80211_start_roc_work() */
272 ret = drv_remain_on_channel(local, roc->chan,
279 wiphy_warn(local->hw.wiphy,
280 "failed to start next HW ROC (%d)\n", ret);
282 * queue the work struct again to avoid recursion
283 * when multiple failures occur
285 ieee80211_remain_on_channel_expired(&local->hw);
289 ieee80211_queue_delayed_work(&local->hw, &roc->work,
290 round_jiffies_relative(HZ/2));
294 void ieee80211_roc_notify_destroy(struct ieee80211_roc_work *roc)
296 struct ieee80211_roc_work *dep, *tmp;
298 /* was never transmitted */
300 cfg80211_mgmt_tx_status(roc->sdata->dev,
301 (unsigned long)roc->frame,
302 roc->frame->data, roc->frame->len,
304 kfree_skb(roc->frame);
307 if (!roc->mgmt_tx_cookie)
308 cfg80211_remain_on_channel_expired(roc->sdata->dev,
310 roc->chan, roc->chan_type,
313 list_for_each_entry_safe(dep, tmp, &roc->dependents, list)
314 ieee80211_roc_notify_destroy(dep);
319 void ieee80211_sw_roc_work(struct work_struct *work)
321 struct ieee80211_roc_work *roc =
322 container_of(work, struct ieee80211_roc_work, work.work);
323 struct ieee80211_sub_if_data *sdata = roc->sdata;
324 struct ieee80211_local *local = sdata->local;
326 mutex_lock(&local->mtx);
331 if (WARN_ON(list_empty(&local->roc_list)))
334 if (WARN_ON(roc != list_first_entry(&local->roc_list,
335 struct ieee80211_roc_work,
340 struct ieee80211_roc_work *dep;
344 /* switch channel etc */
345 ieee80211_recalc_idle(local);
347 local->tmp_channel = roc->chan;
348 local->tmp_channel_type = roc->chan_type;
349 ieee80211_hw_config(local, 0);
351 /* tell userspace or send frame */
352 ieee80211_handle_roc_started(roc);
353 list_for_each_entry(dep, &roc->dependents, list)
354 ieee80211_handle_roc_started(dep);
356 /* if it was pure TX, just finish right away */
361 ieee80211_queue_delayed_work(&local->hw, &roc->work,
362 msecs_to_jiffies(roc->duration));
364 /* finish this ROC */
366 list_del(&roc->list);
367 ieee80211_roc_notify_destroy(roc);
370 drv_flush(local, false);
372 local->tmp_channel = NULL;
373 ieee80211_hw_config(local, 0);
375 ieee80211_offchannel_return(local, true);
378 ieee80211_recalc_idle(local);
380 ieee80211_start_next_roc(local);
384 mutex_unlock(&local->mtx);
387 static void ieee80211_hw_roc_done(struct work_struct *work)
389 struct ieee80211_local *local =
390 container_of(work, struct ieee80211_local, hw_roc_done);
391 struct ieee80211_roc_work *roc;
393 mutex_lock(&local->mtx);
395 if (list_empty(&local->roc_list))
398 roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
404 list_del(&roc->list);
406 ieee80211_roc_notify_destroy(roc);
408 /* if there's another roc, start it now */
409 ieee80211_start_next_roc(local);
412 mutex_unlock(&local->mtx);
415 void ieee80211_remain_on_channel_expired(struct ieee80211_hw *hw)
417 struct ieee80211_local *local = hw_to_local(hw);
419 trace_api_remain_on_channel_expired(local);
421 ieee80211_queue_work(hw, &local->hw_roc_done);
423 EXPORT_SYMBOL_GPL(ieee80211_remain_on_channel_expired);
425 void ieee80211_roc_setup(struct ieee80211_local *local)
427 INIT_WORK(&local->hw_roc_start, ieee80211_hw_roc_start);
428 INIT_WORK(&local->hw_roc_done, ieee80211_hw_roc_done);
429 INIT_LIST_HEAD(&local->roc_list);
432 void ieee80211_roc_purge(struct ieee80211_sub_if_data *sdata)
434 struct ieee80211_local *local = sdata->local;
435 struct ieee80211_roc_work *roc, *tmp;
438 mutex_lock(&local->mtx);
439 list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
440 if (roc->sdata != sdata)
443 if (roc->started && local->ops->remain_on_channel) {
444 /* can race, so ignore return value */
445 drv_cancel_remain_on_channel(local);
448 list_move_tail(&roc->list, &tmp_list);
452 ieee80211_start_next_roc(local);
453 mutex_unlock(&local->mtx);
455 list_for_each_entry_safe(roc, tmp, &tmp_list, list) {
456 if (local->ops->remain_on_channel) {
457 list_del(&roc->list);
458 ieee80211_roc_notify_destroy(roc);
460 ieee80211_queue_delayed_work(&local->hw, &roc->work, 0);
462 /* work will clean up etc */
463 flush_delayed_work(&roc->work);
467 WARN_ON_ONCE(!list_empty(&tmp_list));