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)
107 struct ieee80211_sub_if_data *sdata;
109 if (WARN_ON(local->use_chanctx))
113 * notify the AP about us leaving the channel and stop all
116 mutex_lock(&local->iflist_mtx);
117 list_for_each_entry(sdata, &local->interfaces, list) {
118 if (!ieee80211_sdata_running(sdata))
121 if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE)
124 if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
125 set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
127 /* Check to see if we should disable beaconing. */
128 if (sdata->vif.type == NL80211_IFTYPE_AP ||
129 sdata->vif.type == NL80211_IFTYPE_ADHOC ||
130 sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
131 ieee80211_bss_info_change_notify(
132 sdata, BSS_CHANGED_BEACON_ENABLED);
134 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) {
135 netif_tx_stop_all_queues(sdata->dev);
136 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
137 sdata->u.mgd.associated)
138 ieee80211_offchannel_ps_enable(sdata);
141 mutex_unlock(&local->iflist_mtx);
144 void ieee80211_offchannel_return(struct ieee80211_local *local)
146 struct ieee80211_sub_if_data *sdata;
148 if (WARN_ON(local->use_chanctx))
151 mutex_lock(&local->iflist_mtx);
152 list_for_each_entry(sdata, &local->interfaces, list) {
153 if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE)
156 if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
157 clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
159 if (!ieee80211_sdata_running(sdata))
162 /* Tell AP we're back */
163 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
164 sdata->u.mgd.associated)
165 ieee80211_offchannel_ps_disable(sdata);
167 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) {
169 * This may wake up queues even though the driver
170 * currently has them stopped. This is not very
171 * likely, since the driver won't have gotten any
172 * (or hardly any) new packets while we weren't
173 * on the right channel, and even if it happens
174 * it will at most lead to queueing up one more
175 * packet per queue in mac80211 rather than on
176 * the interface qdisc.
178 netif_tx_wake_all_queues(sdata->dev);
181 if (sdata->vif.type == NL80211_IFTYPE_AP ||
182 sdata->vif.type == NL80211_IFTYPE_ADHOC ||
183 sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
184 ieee80211_bss_info_change_notify(
185 sdata, BSS_CHANGED_BEACON_ENABLED);
187 mutex_unlock(&local->iflist_mtx);
190 void ieee80211_handle_roc_started(struct ieee80211_roc_work *roc)
195 if (roc->mgmt_tx_cookie) {
196 if (!WARN_ON(!roc->frame)) {
197 ieee80211_tx_skb_tid_band(roc->sdata, roc->frame, 7,
202 cfg80211_ready_on_channel(&roc->sdata->wdev, roc->cookie,
203 roc->chan, roc->req_duration,
207 roc->notified = true;
210 static void ieee80211_hw_roc_start(struct work_struct *work)
212 struct ieee80211_local *local =
213 container_of(work, struct ieee80211_local, hw_roc_start);
214 struct ieee80211_roc_work *roc, *dep, *tmp;
216 mutex_lock(&local->mtx);
218 if (list_empty(&local->roc_list))
221 roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
227 roc->hw_begun = true;
228 roc->hw_start_time = local->hw_roc_start_time;
230 ieee80211_handle_roc_started(roc);
231 list_for_each_entry_safe(dep, tmp, &roc->dependents, list) {
232 ieee80211_handle_roc_started(dep);
234 if (dep->duration > roc->duration) {
235 u32 dur = dep->duration;
236 dep->duration = dur - roc->duration;
238 list_move(&dep->list, &roc->list);
242 mutex_unlock(&local->mtx);
245 void ieee80211_ready_on_channel(struct ieee80211_hw *hw)
247 struct ieee80211_local *local = hw_to_local(hw);
249 local->hw_roc_start_time = jiffies;
251 trace_api_ready_on_channel(local);
253 ieee80211_queue_work(hw, &local->hw_roc_start);
255 EXPORT_SYMBOL_GPL(ieee80211_ready_on_channel);
257 void ieee80211_start_next_roc(struct ieee80211_local *local)
259 struct ieee80211_roc_work *roc;
261 lockdep_assert_held(&local->mtx);
263 if (list_empty(&local->roc_list)) {
264 ieee80211_run_deferred_scan(local);
268 roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
271 if (WARN_ON_ONCE(roc->started))
274 if (local->ops->remain_on_channel) {
275 int ret, duration = roc->duration;
277 /* XXX: duplicated, see ieee80211_start_roc_work() */
281 ret = drv_remain_on_channel(local, roc->sdata, roc->chan,
287 wiphy_warn(local->hw.wiphy,
288 "failed to start next HW ROC (%d)\n", ret);
290 * queue the work struct again to avoid recursion
291 * when multiple failures occur
293 ieee80211_remain_on_channel_expired(&local->hw);
297 ieee80211_queue_delayed_work(&local->hw, &roc->work,
298 round_jiffies_relative(HZ/2));
302 void ieee80211_roc_notify_destroy(struct ieee80211_roc_work *roc)
304 struct ieee80211_roc_work *dep, *tmp;
306 /* was never transmitted */
308 cfg80211_mgmt_tx_status(&roc->sdata->wdev,
309 (unsigned long)roc->frame,
310 roc->frame->data, roc->frame->len,
312 kfree_skb(roc->frame);
315 if (!roc->mgmt_tx_cookie)
316 cfg80211_remain_on_channel_expired(&roc->sdata->wdev,
317 roc->cookie, roc->chan,
320 list_for_each_entry_safe(dep, tmp, &roc->dependents, list)
321 ieee80211_roc_notify_destroy(dep);
326 void ieee80211_sw_roc_work(struct work_struct *work)
328 struct ieee80211_roc_work *roc =
329 container_of(work, struct ieee80211_roc_work, work.work);
330 struct ieee80211_sub_if_data *sdata = roc->sdata;
331 struct ieee80211_local *local = sdata->local;
334 mutex_lock(&local->mtx);
339 if (WARN_ON(list_empty(&local->roc_list)))
342 if (WARN_ON(roc != list_first_entry(&local->roc_list,
343 struct ieee80211_roc_work,
348 struct ieee80211_roc_work *dep;
352 /* switch channel etc */
353 ieee80211_recalc_idle(local);
355 local->tmp_channel = roc->chan;
356 ieee80211_hw_config(local, 0);
358 /* tell userspace or send frame */
359 ieee80211_handle_roc_started(roc);
360 list_for_each_entry(dep, &roc->dependents, list)
361 ieee80211_handle_roc_started(dep);
363 /* if it was pure TX, just finish right away */
368 ieee80211_queue_delayed_work(&local->hw, &roc->work,
369 msecs_to_jiffies(roc->duration));
371 /* finish this ROC */
373 list_del(&roc->list);
374 started = roc->started;
375 ieee80211_roc_notify_destroy(roc);
378 drv_flush(local, false);
380 local->tmp_channel = NULL;
381 ieee80211_hw_config(local, 0);
383 ieee80211_offchannel_return(local);
386 ieee80211_recalc_idle(local);
389 ieee80211_start_next_roc(local);
393 mutex_unlock(&local->mtx);
396 static void ieee80211_hw_roc_done(struct work_struct *work)
398 struct ieee80211_local *local =
399 container_of(work, struct ieee80211_local, hw_roc_done);
400 struct ieee80211_roc_work *roc;
402 mutex_lock(&local->mtx);
404 if (list_empty(&local->roc_list))
407 roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
413 list_del(&roc->list);
415 ieee80211_roc_notify_destroy(roc);
417 /* if there's another roc, start it now */
418 ieee80211_start_next_roc(local);
421 mutex_unlock(&local->mtx);
424 void ieee80211_remain_on_channel_expired(struct ieee80211_hw *hw)
426 struct ieee80211_local *local = hw_to_local(hw);
428 trace_api_remain_on_channel_expired(local);
430 ieee80211_queue_work(hw, &local->hw_roc_done);
432 EXPORT_SYMBOL_GPL(ieee80211_remain_on_channel_expired);
434 void ieee80211_roc_setup(struct ieee80211_local *local)
436 INIT_WORK(&local->hw_roc_start, ieee80211_hw_roc_start);
437 INIT_WORK(&local->hw_roc_done, ieee80211_hw_roc_done);
438 INIT_LIST_HEAD(&local->roc_list);
441 void ieee80211_roc_purge(struct ieee80211_sub_if_data *sdata)
443 struct ieee80211_local *local = sdata->local;
444 struct ieee80211_roc_work *roc, *tmp;
447 mutex_lock(&local->mtx);
448 list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
449 if (roc->sdata != sdata)
452 if (roc->started && local->ops->remain_on_channel) {
453 /* can race, so ignore return value */
454 drv_cancel_remain_on_channel(local);
457 list_move_tail(&roc->list, &tmp_list);
460 mutex_unlock(&local->mtx);
462 list_for_each_entry_safe(roc, tmp, &tmp_list, list) {
463 if (local->ops->remain_on_channel) {
464 list_del(&roc->list);
465 ieee80211_roc_notify_destroy(roc);
467 ieee80211_queue_delayed_work(&local->hw, &roc->work, 0);
469 /* work will clean up etc */
470 flush_delayed_work(&roc->work);
474 WARN_ON_ONCE(!list_empty(&tmp_list));