mac80211: quiesce vif before suspending
[linux-2.6.git] / net / mac80211 / offchannel.c
1 /*
2  * Off-channel operation helpers
3  *
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>
10  *
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.
14  */
15 #include <net/mac80211.h>
16 #include "ieee80211_i.h"
17 #include "driver-trace.h"
18
19 /*
20  * Tell our hardware to disable PS.
21  * Optionally inform AP that we will go to sleep so that it will buffer
22  * the frames while we are doing off-channel work.  This is optional
23  * because we *may* be doing work on-operating channel, and want our
24  * hardware unconditionally awake, but still let the AP send us normal frames.
25  */
26 static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata,
27                                            bool tell_ap)
28 {
29         struct ieee80211_local *local = sdata->local;
30         struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
31
32         local->offchannel_ps_enabled = false;
33
34         /* FIXME: what to do when local->pspolling is true? */
35
36         del_timer_sync(&local->dynamic_ps_timer);
37         del_timer_sync(&ifmgd->bcn_mon_timer);
38         del_timer_sync(&ifmgd->conn_mon_timer);
39
40         cancel_work_sync(&local->dynamic_ps_enable_work);
41
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);
46         }
47
48         if (tell_ap && (!local->offchannel_ps_enabled ||
49                         !(local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK)))
50                 /*
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
58                  * are again sleeping.
59                  */
60                 ieee80211_send_nullfunc(local, sdata, 1);
61 }
62
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)
65 {
66         struct ieee80211_local *local = sdata->local;
67
68         if (!local->ps_sdata)
69                 ieee80211_send_nullfunc(local, sdata, 0);
70         else if (local->offchannel_ps_enabled) {
71                 /*
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.
78                  *
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
82                  * hardware.
83                  */
84                 /* TODO:  Only set hardware if CONF_PS changed?
85                  * TODO:  Should we set offchannel_ps_enabled to false?
86                  */
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) {
90                 /*
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.
95                  */
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));
99         }
100
101         ieee80211_sta_reset_beacon_monitor(sdata);
102         ieee80211_sta_reset_conn_monitor(sdata);
103 }
104
105 void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local,
106                                     bool offchannel_ps_enable)
107 {
108         struct ieee80211_sub_if_data *sdata;
109
110         /*
111          * notify the AP about us leaving the channel and stop all
112          * STA interfaces.
113          */
114         mutex_lock(&local->iflist_mtx);
115         list_for_each_entry(sdata, &local->interfaces, list) {
116                 if (!ieee80211_sdata_running(sdata))
117                         continue;
118
119                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
120                         set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
121
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);
128
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, true);
135                 }
136         }
137         mutex_unlock(&local->iflist_mtx);
138 }
139
140 void ieee80211_offchannel_enable_all_ps(struct ieee80211_local *local,
141                                         bool tell_ap)
142 {
143         struct ieee80211_sub_if_data *sdata;
144
145         mutex_lock(&local->iflist_mtx);
146         list_for_each_entry(sdata, &local->interfaces, list) {
147                 if (!ieee80211_sdata_running(sdata))
148                         continue;
149
150                 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
151                     sdata->u.mgd.associated)
152                         ieee80211_offchannel_ps_enable(sdata, tell_ap);
153         }
154         mutex_unlock(&local->iflist_mtx);
155 }
156
157 void ieee80211_offchannel_return(struct ieee80211_local *local,
158                                  bool enable_beaconing,
159                                  bool offchannel_ps_disable)
160 {
161         struct ieee80211_sub_if_data *sdata;
162
163         mutex_lock(&local->iflist_mtx);
164         list_for_each_entry(sdata, &local->interfaces, list) {
165                 if (!ieee80211_sdata_running(sdata))
166                         continue;
167
168                 /* Tell AP we're back */
169                 if (offchannel_ps_disable &&
170                     sdata->vif.type == NL80211_IFTYPE_STATION) {
171                         if (sdata->u.mgd.associated)
172                                 ieee80211_offchannel_ps_disable(sdata);
173                 }
174
175                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) {
176                         clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
177                         /*
178                          * This may wake up queues even though the driver
179                          * currently has them stopped. This is not very
180                          * likely, since the driver won't have gotten any
181                          * (or hardly any) new packets while we weren't
182                          * on the right channel, and even if it happens
183                          * it will at most lead to queueing up one more
184                          * packet per queue in mac80211 rather than on
185                          * the interface qdisc.
186                          */
187                         netif_tx_wake_all_queues(sdata->dev);
188                 }
189
190                 /* Check to see if we should re-enable beaconing */
191                 if (enable_beaconing &&
192                     (sdata->vif.type == NL80211_IFTYPE_AP ||
193                      sdata->vif.type == NL80211_IFTYPE_ADHOC ||
194                      sdata->vif.type == NL80211_IFTYPE_MESH_POINT))
195                         ieee80211_bss_info_change_notify(
196                                 sdata, BSS_CHANGED_BEACON_ENABLED);
197         }
198         mutex_unlock(&local->iflist_mtx);
199 }
200
201 static void ieee80211_hw_roc_start(struct work_struct *work)
202 {
203         struct ieee80211_local *local =
204                 container_of(work, struct ieee80211_local, hw_roc_start);
205         struct ieee80211_sub_if_data *sdata;
206
207         mutex_lock(&local->mtx);
208
209         if (!local->hw_roc_channel) {
210                 mutex_unlock(&local->mtx);
211                 return;
212         }
213
214         ieee80211_recalc_idle(local);
215
216         if (local->hw_roc_skb) {
217                 sdata = IEEE80211_DEV_TO_SUB_IF(local->hw_roc_dev);
218                 ieee80211_tx_skb(sdata, local->hw_roc_skb);
219                 local->hw_roc_skb = NULL;
220         } else {
221                 cfg80211_ready_on_channel(local->hw_roc_dev,
222                                           local->hw_roc_cookie,
223                                           local->hw_roc_channel,
224                                           local->hw_roc_channel_type,
225                                           local->hw_roc_duration,
226                                           GFP_KERNEL);
227         }
228
229         mutex_unlock(&local->mtx);
230 }
231
232 void ieee80211_ready_on_channel(struct ieee80211_hw *hw)
233 {
234         struct ieee80211_local *local = hw_to_local(hw);
235
236         trace_api_ready_on_channel(local);
237
238         ieee80211_queue_work(hw, &local->hw_roc_start);
239 }
240 EXPORT_SYMBOL_GPL(ieee80211_ready_on_channel);
241
242 static void ieee80211_hw_roc_done(struct work_struct *work)
243 {
244         struct ieee80211_local *local =
245                 container_of(work, struct ieee80211_local, hw_roc_done);
246
247         mutex_lock(&local->mtx);
248
249         if (!local->hw_roc_channel) {
250                 mutex_unlock(&local->mtx);
251                 return;
252         }
253
254         if (!local->hw_roc_for_tx)
255                 cfg80211_remain_on_channel_expired(local->hw_roc_dev,
256                                                    local->hw_roc_cookie,
257                                                    local->hw_roc_channel,
258                                                    local->hw_roc_channel_type,
259                                                    GFP_KERNEL);
260
261         local->hw_roc_channel = NULL;
262         local->hw_roc_cookie = 0;
263
264         ieee80211_recalc_idle(local);
265
266         mutex_unlock(&local->mtx);
267 }
268
269 void ieee80211_remain_on_channel_expired(struct ieee80211_hw *hw)
270 {
271         struct ieee80211_local *local = hw_to_local(hw);
272
273         trace_api_remain_on_channel_expired(local);
274
275         ieee80211_queue_work(hw, &local->hw_roc_done);
276 }
277 EXPORT_SYMBOL_GPL(ieee80211_remain_on_channel_expired);
278
279 void ieee80211_hw_roc_setup(struct ieee80211_local *local)
280 {
281         INIT_WORK(&local->hw_roc_start, ieee80211_hw_roc_start);
282         INIT_WORK(&local->hw_roc_done, ieee80211_hw_roc_done);
283 }