ath9k_htc: Fix fair beacon distribution
[linux-2.6.git] / drivers / net / wireless / ath / ath9k / htc_drv_beacon.c
1 /*
2  * Copyright (c) 2010 Atheros Communications Inc.
3  *
4  * Permission to use, copy, modify, and/or distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16
17 #include "htc.h"
18
19 #define FUDGE 2
20
21 static void ath9k_htc_beacon_config_sta(struct ath9k_htc_priv *priv,
22                                         struct htc_beacon_config *bss_conf)
23 {
24         struct ath_common *common = ath9k_hw_common(priv->ah);
25         struct ath9k_beacon_state bs;
26         enum ath9k_int imask = 0;
27         int dtimperiod, dtimcount, sleepduration;
28         int cfpperiod, cfpcount, bmiss_timeout;
29         u32 nexttbtt = 0, intval, tsftu;
30         __be32 htc_imask = 0;
31         u64 tsf;
32         int num_beacons, offset, dtim_dec_count, cfp_dec_count;
33         int ret;
34         u8 cmd_rsp;
35
36         memset(&bs, 0, sizeof(bs));
37
38         intval = bss_conf->beacon_interval & ATH9K_BEACON_PERIOD;
39         bmiss_timeout = (ATH_DEFAULT_BMISS_LIMIT * bss_conf->beacon_interval);
40
41         /*
42          * Setup dtim and cfp parameters according to
43          * last beacon we received (which may be none).
44          */
45         dtimperiod = bss_conf->dtim_period;
46         if (dtimperiod <= 0)            /* NB: 0 if not known */
47                 dtimperiod = 1;
48         dtimcount = 1;
49         if (dtimcount >= dtimperiod)    /* NB: sanity check */
50                 dtimcount = 0;
51         cfpperiod = 1;                  /* NB: no PCF support yet */
52         cfpcount = 0;
53
54         sleepduration = intval;
55         if (sleepduration <= 0)
56                 sleepduration = intval;
57
58         /*
59          * Pull nexttbtt forward to reflect the current
60          * TSF and calculate dtim+cfp state for the result.
61          */
62         tsf = ath9k_hw_gettsf64(priv->ah);
63         tsftu = TSF_TO_TU(tsf>>32, tsf) + FUDGE;
64
65         num_beacons = tsftu / intval + 1;
66         offset = tsftu % intval;
67         nexttbtt = tsftu - offset;
68         if (offset)
69                 nexttbtt += intval;
70
71         /* DTIM Beacon every dtimperiod Beacon */
72         dtim_dec_count = num_beacons % dtimperiod;
73         /* CFP every cfpperiod DTIM Beacon */
74         cfp_dec_count = (num_beacons / dtimperiod) % cfpperiod;
75         if (dtim_dec_count)
76                 cfp_dec_count++;
77
78         dtimcount -= dtim_dec_count;
79         if (dtimcount < 0)
80                 dtimcount += dtimperiod;
81
82         cfpcount -= cfp_dec_count;
83         if (cfpcount < 0)
84                 cfpcount += cfpperiod;
85
86         bs.bs_intval = intval;
87         bs.bs_nexttbtt = nexttbtt;
88         bs.bs_dtimperiod = dtimperiod*intval;
89         bs.bs_nextdtim = bs.bs_nexttbtt + dtimcount*intval;
90         bs.bs_cfpperiod = cfpperiod*bs.bs_dtimperiod;
91         bs.bs_cfpnext = bs.bs_nextdtim + cfpcount*bs.bs_dtimperiod;
92         bs.bs_cfpmaxduration = 0;
93
94         /*
95          * Calculate the number of consecutive beacons to miss* before taking
96          * a BMISS interrupt. The configuration is specified in TU so we only
97          * need calculate based on the beacon interval.  Note that we clamp the
98          * result to at most 15 beacons.
99          */
100         if (sleepduration > intval) {
101                 bs.bs_bmissthreshold = ATH_DEFAULT_BMISS_LIMIT / 2;
102         } else {
103                 bs.bs_bmissthreshold = DIV_ROUND_UP(bmiss_timeout, intval);
104                 if (bs.bs_bmissthreshold > 15)
105                         bs.bs_bmissthreshold = 15;
106                 else if (bs.bs_bmissthreshold <= 0)
107                         bs.bs_bmissthreshold = 1;
108         }
109
110         /*
111          * Calculate sleep duration. The configuration is given in ms.
112          * We ensure a multiple of the beacon period is used. Also, if the sleep
113          * duration is greater than the DTIM period then it makes senses
114          * to make it a multiple of that.
115          *
116          * XXX fixed at 100ms
117          */
118
119         bs.bs_sleepduration = roundup(IEEE80211_MS_TO_TU(100), sleepduration);
120         if (bs.bs_sleepduration > bs.bs_dtimperiod)
121                 bs.bs_sleepduration = bs.bs_dtimperiod;
122
123         /* TSF out of range threshold fixed at 1 second */
124         bs.bs_tsfoor_threshold = ATH9K_TSFOOR_THRESHOLD;
125
126         ath_print(common, ATH_DBG_BEACON, "tsf: %llu tsftu: %u\n", tsf, tsftu);
127         ath_print(common, ATH_DBG_BEACON,
128                   "bmiss: %u sleep: %u cfp-period: %u maxdur: %u next: %u\n",
129                   bs.bs_bmissthreshold, bs.bs_sleepduration,
130                   bs.bs_cfpperiod, bs.bs_cfpmaxduration, bs.bs_cfpnext);
131
132         /* Set the computed STA beacon timers */
133
134         WMI_CMD(WMI_DISABLE_INTR_CMDID);
135         ath9k_hw_set_sta_beacon_timers(priv->ah, &bs);
136         imask |= ATH9K_INT_BMISS;
137         htc_imask = cpu_to_be32(imask);
138         WMI_CMD_BUF(WMI_ENABLE_INTR_CMDID, &htc_imask);
139 }
140
141 static void ath9k_htc_beacon_config_adhoc(struct ath9k_htc_priv *priv,
142                                           struct htc_beacon_config *bss_conf)
143 {
144         struct ath_common *common = ath9k_hw_common(priv->ah);
145         enum ath9k_int imask = 0;
146         u32 nexttbtt, intval;
147         __be32 htc_imask = 0;
148         int ret;
149         u8 cmd_rsp;
150
151         intval = bss_conf->beacon_interval & ATH9K_BEACON_PERIOD;
152         nexttbtt = intval;
153         intval |= ATH9K_BEACON_ENA;
154         if (priv->op_flags & OP_ENABLE_BEACON)
155                 imask |= ATH9K_INT_SWBA;
156
157         ath_print(common, ATH_DBG_BEACON,
158                   "IBSS Beacon config, intval: %d, imask: 0x%x\n",
159                   bss_conf->beacon_interval, imask);
160
161         WMI_CMD(WMI_DISABLE_INTR_CMDID);
162         ath9k_hw_beaconinit(priv->ah, nexttbtt, intval);
163         priv->bmiss_cnt = 0;
164         htc_imask = cpu_to_be32(imask);
165         WMI_CMD_BUF(WMI_ENABLE_INTR_CMDID, &htc_imask);
166 }
167
168 void ath9k_htc_beaconep(void *drv_priv, struct sk_buff *skb,
169                         enum htc_endpoint_id ep_id, bool txok)
170 {
171         dev_kfree_skb_any(skb);
172 }
173
174 void ath9k_htc_swba(struct ath9k_htc_priv *priv, u8 beacon_pending)
175 {
176         struct ath9k_htc_vif *avp = (void *)priv->vif->drv_priv;
177         struct tx_beacon_header beacon_hdr;
178         struct ath9k_htc_tx_ctl tx_ctl;
179         struct ieee80211_tx_info *info;
180         struct sk_buff *beacon;
181         u8 *tx_fhdr;
182
183         memset(&beacon_hdr, 0, sizeof(struct tx_beacon_header));
184         memset(&tx_ctl, 0, sizeof(struct ath9k_htc_tx_ctl));
185
186         /* FIXME: Handle BMISS */
187         if (beacon_pending != 0) {
188                 priv->bmiss_cnt++;
189                 return;
190         }
191
192         spin_lock_bh(&priv->beacon_lock);
193
194         if (unlikely(priv->op_flags & OP_SCANNING)) {
195                 spin_unlock_bh(&priv->beacon_lock);
196                 return;
197         }
198
199         /* Get a new beacon */
200         beacon = ieee80211_beacon_get(priv->hw, priv->vif);
201         if (!beacon) {
202                 spin_unlock_bh(&priv->beacon_lock);
203                 return;
204         }
205
206         info = IEEE80211_SKB_CB(beacon);
207         if (info->flags & IEEE80211_TX_CTL_ASSIGN_SEQ) {
208                 struct ieee80211_hdr *hdr =
209                         (struct ieee80211_hdr *) beacon->data;
210                 priv->seq_no += 0x10;
211                 hdr->seq_ctrl &= cpu_to_le16(IEEE80211_SCTL_FRAG);
212                 hdr->seq_ctrl |= cpu_to_le16(priv->seq_no);
213         }
214
215         tx_ctl.type = ATH9K_HTC_NORMAL;
216         beacon_hdr.vif_index = avp->index;
217         tx_fhdr = skb_push(beacon, sizeof(beacon_hdr));
218         memcpy(tx_fhdr, (u8 *) &beacon_hdr, sizeof(beacon_hdr));
219
220         htc_send(priv->htc, beacon, priv->beacon_ep, &tx_ctl);
221
222         spin_unlock_bh(&priv->beacon_lock);
223 }
224
225 /* Currently, only for IBSS */
226 void ath9k_htc_beaconq_config(struct ath9k_htc_priv *priv)
227 {
228         struct ath_hw *ah = priv->ah;
229         struct ath9k_tx_queue_info qi, qi_be;
230         int qnum = priv->hwq_map[ATH9K_WME_AC_BE];
231
232         memset(&qi, 0, sizeof(struct ath9k_tx_queue_info));
233         memset(&qi_be, 0, sizeof(struct ath9k_tx_queue_info));
234
235         ath9k_hw_get_txq_props(ah, qnum, &qi_be);
236
237         qi.tqi_aifs = qi_be.tqi_aifs;
238         qi.tqi_cwmin = 4*qi_be.tqi_cwmin;
239         qi.tqi_cwmax = qi_be.tqi_cwmax;
240
241         if (!ath9k_hw_set_txq_props(ah, priv->beaconq, &qi)) {
242                 ath_print(ath9k_hw_common(ah), ATH_DBG_FATAL,
243                           "Unable to update beacon queue %u!\n", qnum);
244         } else {
245                 ath9k_hw_resettxqueue(ah, priv->beaconq);
246         }
247 }
248
249 void ath9k_htc_beacon_config(struct ath9k_htc_priv *priv,
250                              struct ieee80211_vif *vif)
251 {
252         struct ath_common *common = ath9k_hw_common(priv->ah);
253         struct htc_beacon_config *cur_conf = &priv->cur_beacon_conf;
254         struct ieee80211_bss_conf *bss_conf = &vif->bss_conf;
255
256         cur_conf->beacon_interval = bss_conf->beacon_int;
257         if (cur_conf->beacon_interval == 0)
258                 cur_conf->beacon_interval = 100;
259
260         cur_conf->dtim_period = bss_conf->dtim_period;
261         cur_conf->listen_interval = 1;
262         cur_conf->dtim_count = 1;
263         cur_conf->bmiss_timeout =
264                 ATH_DEFAULT_BMISS_LIMIT * cur_conf->beacon_interval;
265
266         switch (vif->type) {
267         case NL80211_IFTYPE_STATION:
268                 ath9k_htc_beacon_config_sta(priv, cur_conf);
269                 break;
270         case NL80211_IFTYPE_ADHOC:
271                 ath9k_htc_beacon_config_adhoc(priv, cur_conf);
272                 break;
273         default:
274                 ath_print(common, ATH_DBG_CONFIG,
275                           "Unsupported beaconing mode\n");
276                 return;
277         }
278 }