43  * AMRR rate control. See:
45  * "IEEE 802.11 Rate Adaptation: A Practical Approach" by
83 static	int ath_rateinterval = 1000;		/* rate ctl interval (ms)  */
88 			int rate);
125  * the returned rate with the relevant preamble rate flag.
218  * The code below assumes that we are dealing with hardware multi rate retry
224 ath_rate_update(struct ath_softc *sc, struct ieee80211_node *ni, int rate)  in ath_rate_update()  argument
232 	KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode));  in ath_rate_update()
235 	    "%s: set xmit rate to %dM", __func__,   in ath_rate_update()
237 		(ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL) / 2 : 0);  in ath_rate_update()
239 	amn->amn_rix = rate;  in ath_rate_update()
241 	 * Before associating a node has no rate set setup  in ath_rate_update()
245 	 * lowest hardware rate.  in ath_rate_update()
248 		ni->ni_txrate = ni->ni_rates.rs_rates[rate] & IEEE80211_RATE_VAL;  in ath_rate_update()
258 			if (--rate >= 0) {  in ath_rate_update()
260 						    ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL];  in ath_rate_update()
267 			if (--rate >= 0) {  in ath_rate_update()
269 						    ni->ni_rates.rs_rates[rate]&IEEE80211_RATE_VAL];  in ath_rate_update()
276 			if (rate > 0) {  in ath_rate_update()
306  * Set the starting transmit rate for a node.
311 #define	RATE(_ix)	(ni->ni_rates.rs_rates[(_ix)] & IEEE80211_RATE_VAL)  in ath_rate_ctl_start()  macro
318 		 * No fixed rate is requested. For 11b start with  in ath_rate_ctl_start()
319 		 * the highest negotiated rate; otherwise, for 11g  in ath_rate_ctl_start()
325 			 * Scan the negotiated rate set to find the  in ath_rate_ctl_start()
326 			 * closest rate.  in ath_rate_ctl_start()
328 			/* NB: the rate set is assumed sorted */  in ath_rate_ctl_start()
329 			for (; srate >= 0 && RATE(srate) > 72; srate--)  in ath_rate_ctl_start()
334 		 * A fixed rate is to be used; ic_fixed_rate is the  in ath_rate_ctl_start()
335 		 * IEEE code for this rate (sans basic bit).  Convert this  in ath_rate_ctl_start()
336 		 * to the index into the negotiated rate set for  in ath_rate_ctl_start()
337 		 * the node.  We know the rate is there because the  in ath_rate_ctl_start()
338 		 * rate set is checked when the station associates.  in ath_rate_ctl_start()
340 		/* NB: the rate set is assumed sorted */  in ath_rate_ctl_start()
342 		for (; srate >= 0 && RATE(srate) != tp->ucastrate; srate--)  in ath_rate_ctl_start()
346 	 * The selected rate may not be available due to races  in ath_rate_ctl_start()
348 	 * adhoc mode may not have any rate set so this lookup  in ath_rate_ctl_start()
352 #undef RATE  in ath_rate_ctl_start()
356  * Examine and potentially adjust the transmit rate.
386 			    "increase rate to %d", rix);  in ath_rate_ctl()
400 				    "decrease rate recovery thr: %d",  in ath_rate_ctl()
407 				    "decrease rate normal thr: %d",  in ath_rate_ctl()
445 		"rate control: operation interval (ms)");  in ath_rate_sysctlattach()