sample.c

最新之atheros芯片driver source code, 基于linux操作系统,內含atheros芯片HAL全部代码

	if (sn->num_rates <= 0) {
		printk(KERN_WARNING "%s: no rates for " MAC_FMT "?\n",
		       dev_info,
		       MAC_ADDR(an->an_node.ni_macaddr));
		return;
	}

	mrr = sc->sc_mrretry && !(ic->ic_flags & IEEE80211_F_USEPROT) && ENABLE_MRR;
	size_bin = size_to_bin(frameLen);
	best_ndx = best_rate_ndx(sn, size_bin, !mrr);

	if (best_ndx >= 0)
		average_tx_time = sn->stats[size_bin][best_ndx].average_tx_time;
	else
		average_tx_time = 0;

	if (sn->static_rate_ndx != -1) {
		ndx = sn->static_rate_ndx;
		*try0 = ATH_TXMAXTRY;
	} else {
		*try0 = mrr ? 2 : ATH_TXMAXTRY;

		if (sn->sample_tt[size_bin] < average_tx_time * (sn->packets_since_sample[size_bin] * ssc->ath_sample_rate / 100)) {
			/*
			 * we want to limit the time measuring the performance
			 * of other bit-rates to ath_sample_rate% of the
			 * total transmission time.
			 */
			ndx = pick_sample_ndx(sn, size_bin);
			if (ndx != sn->current_rate[size_bin])
				sn->current_sample_ndx[size_bin] = ndx;
			else
				sn->current_sample_ndx[size_bin] = -1;
			sn->packets_since_sample[size_bin] = 0;

		} else {
			change_rates = 0;
			if (!sn->packets_sent[size_bin] || best_ndx == -1) {
				/* no packet has been sent successfully yet, so
				 * pick an rssi-appropriate bit-rate. We know if
				 * the rssi is very low that the really high
				 * bit rates will not work.
				 */
				int initial_rate = 72;
				if (an->an_avgrssi > 50) {
					initial_rate = 108; /* 54 mbps */
				} else if (an->an_avgrssi > 30) {
					initial_rate = 72; /* 36 mbps */
				} else {
					initial_rate = 22; /* 11 mbps */
				}

				for (ndx = sn->num_rates-1; ndx > 0; ndx--) {
					/* 
					 * pick the highest rate <= initial_rate/2 Mbps
					 * that hasn't failed.
					 */
					if (sn->rates[ndx].rate <= initial_rate &&
					    sn->stats[size_bin][ndx].successive_failures == 0)
						break;
				}
				change_rates = 1;
				best_ndx = ndx;
			} else if (sn->packets_sent[size_bin] < 20) {
				/* let the bit-rate switch quickly during the first few packets */
				change_rates = 1;
			} else if (time_after(jiffies,
					sn->jiffies_since_switch[size_bin] +
					((HZ * MIN_SWITCH_MS) / 1000))) {
				/* 2 seconds have gone by */
				change_rates = 1;
			} else if (average_tx_time * 2 < sn->stats[size_bin][sn->current_rate[size_bin]].average_tx_time) {
				/* the current bit-rate is twice as slow as the best one */
				change_rates = 1;
			}

			sn->packets_since_sample[size_bin]++;

			if (change_rates) {
				if (best_ndx != sn->current_rate[size_bin]) {
					DPRINTF(sc, ATH_DEBUG_RATE, "%s: " MAC_FMT " size %u switch rate %u (%u/%u) -> %u (%u/%u) after %u packets mrr %u\n",
						dev_info,
						MAC_ADDR(an->an_node.ni_macaddr),
						packet_size_bins[size_bin],
						sn->rates[sn->current_rate[size_bin]].rate,
						sn->stats[size_bin][sn->current_rate[size_bin]].average_tx_time,
						sn->stats[size_bin][sn->current_rate[size_bin]].perfect_tx_time,
						sn->rates[best_ndx].rate,
						sn->stats[size_bin][best_ndx].average_tx_time,
						sn->stats[size_bin][best_ndx].perfect_tx_time,
						sn->packets_since_switch[size_bin],
						mrr);
				}
				sn->packets_since_switch[size_bin] = 0;
				sn->current_rate[size_bin] = best_ndx;
				sn->jiffies_since_switch[size_bin] = jiffies;
			}
			ndx = sn->current_rate[size_bin];
			sn->packets_since_switch[size_bin]++;
			if (size_bin == 0) {
				/* 
				 * set the visible txrate for this node
			         * to the rate of small packets
			         */
				an->an_node.ni_txrate = ndx;
			}
		}
	}

	KASSERT(ndx >= 0 && ndx < sn->num_rates,
		("%s: bad ndx (%u/%u) for " MAC_FMT "?",
		 dev_info, ndx, sn->num_rates,
		 MAC_ADDR(an->an_node.ni_macaddr)));


	*rix = sn->rates[ndx].rix;
	if (shortPreamble)
		*txrate = sn->rates[ndx].shortPreambleRateCode;
	else
		*txrate = sn->rates[ndx].rateCode;
	sn->packets_sent[size_bin]++;
}

static void
ath_rate_get_mrr(struct ath_softc *sc, struct ath_node *an, int shortPreamble,
		 size_t frame_size, u_int8_t rix, struct ieee80211_mrr *mrr)
{
	struct sample_node *sn = ATH_NODE_SAMPLE(an);
	unsigned int size_bin;
	int ndx;

	size_bin = size_to_bin(frame_size);
	ndx = sn->current_rate[size_bin]; /* retry at the current bit-rate */

	if (!sn->stats[size_bin][ndx].packets_acked)
		ndx = 0;  /* use the lowest bit-rate */

	if (shortPreamble)
		mrr->rate1 = sn->rates[ndx].shortPreambleRateCode;
	else
		mrr->rate1 = sn->rates[ndx].rateCode;

	mrr->retries1 = 3;
	mrr->rate2 = sn->rates[0].rateCode;
	mrr->retries2 = 3;
	mrr->rate3 = 0;
	mrr->retries3 = 0;
}

static void
update_stats(struct ath_softc *sc, struct ath_node *an,
	int frame_size,
	int ndx0, int tries0,
	int ndx1, int tries1,
	int ndx2, int tries2,
	int ndx3, int tries3,
	int short_tries, int tries, int status)
{
	const HAL_RATE_TABLE *rt = sc->sc_currates;
	struct sample_node *sn = ATH_NODE_SAMPLE(an);
	struct sample_softc *ssc = ATH_SOFTC_SAMPLE(sc);
	unsigned int tt = 0;
	unsigned int tries_so_far = 0;
	unsigned int size_bin;
	unsigned int size;
	unsigned int rate;

	size_bin = size_to_bin(frame_size);
	size = bin_to_size(size_bin);

	if (!(0 <= ndx0 && ndx0 < sn->num_rates)) {
		printk("%s: bogus ndx0 %d, max %u, mode %u\n",
				__func__, ndx0, sn->num_rates, sc->sc_curmode);
		return;
	}
	rate = sn->rates[ndx0].rate;

	if (!rt->info[ndx0].rateKbps) {
		/* 
		 * sometimes we get feedback back for packets we didn't send. 
		 * just ignore these packets.
		 */
		return;
	}
	tt += calc_usecs_unicast_packet(sc, size, sn->rates[ndx0].rix,
		short_tries,
		MIN(tries0, tries) - 1);
	tries_so_far += tries0;
	if (tries1 && (tries0 < tries)) {
		if (!(0 <= ndx1 && ndx1 < sn->num_rates)) {
			printk("%s: bogus ndx1 %d, max %u, mode %u\n",
					__func__, ndx1, sn->num_rates, sc->sc_curmode);
			return;
		}
		tt += calc_usecs_unicast_packet(sc, size, sn->rates[ndx1].rix,
			short_tries,
			MIN(tries1 + tries_so_far, tries) - tries_so_far - 1);
	}
	tries_so_far += tries1;

	if (tries2 && ((tries0 + tries1) < tries)) {
		if (!(0 <= ndx2 && ndx2 < sn->num_rates)) {
			printk("%s: bogus ndx2 %d, max %u, mode %u\n",
					__func__, ndx2, sn->num_rates, sc->sc_curmode);
			return;
		}
		tt += calc_usecs_unicast_packet(sc, size, sn->rates[ndx2].rix,
			short_tries,
			MIN(tries2 + tries_so_far, tries) - tries_so_far - 1);
	}

	tries_so_far += tries2;

	if (tries3 && ((tries0 + tries1 + tries2) < tries)) {
		if (!(0 <= ndx3 && ndx3 < sn->num_rates)) {
			printk("%s: bogus ndx3 %d, max %u, mode %u\n",
					__func__, ndx3, sn->num_rates, sc->sc_curmode);
			return;
		}
		tt += calc_usecs_unicast_packet(sc, size, sn->rates[ndx3].rix,
			short_tries,
			MIN(tries3 + tries_so_far, tries) - tries_so_far - 1);
	}

	if (sn->stats[size_bin][ndx0].total_packets < (100 / (100 - ssc->ath_smoothing_rate))) {
		/* just average the first few packets */
		unsigned int avg_tx = sn->stats[size_bin][ndx0].average_tx_time;
		unsigned int packets = sn->stats[size_bin][ndx0].total_packets;
		sn->stats[size_bin][ndx0].average_tx_time =
			(tt + (avg_tx * packets)) / (packets + 1);
	} else {
		/* use a ewma */
		sn->stats[size_bin][ndx0].average_tx_time =
			((sn->stats[size_bin][ndx0].average_tx_time * ssc->ath_smoothing_rate) +
			 (tt * (100 - ssc->ath_smoothing_rate))) / 100;
	}

	if (status) {
		unsigned int y;
		sn->stats[size_bin][ndx0].successive_failures++;
		for (y = size_bin + 1; y < NUM_PACKET_SIZE_BINS; y++) {
			/* also say larger packets failed since we
			 * assume if a small packet fails at a lower
			 * bit-rate then a larger one will also.
			 */
			sn->stats[y][ndx0].successive_failures++;
			sn->stats[y][ndx0].last_tx = jiffies;
			sn->stats[y][ndx0].tries += tries;
			sn->stats[y][ndx0].total_packets++;
		}
	} else {
		sn->stats[size_bin][ndx0].packets_acked++;
		sn->stats[size_bin][ndx0].successive_failures = 0;
	}
	sn->stats[size_bin][ndx0].tries += tries;
	sn->stats[size_bin][ndx0].last_tx = jiffies;
	sn->stats[size_bin][ndx0].total_packets++;

	if (ndx0 == sn->current_sample_ndx[size_bin]) {
		DPRINTF(sc, ATH_DEBUG_RATE, "%s: " MAC_FMT " size %u sample rate %u tries (%u/%u) tt %u avg_tt (%u/%u) status %u\n",
			dev_info, MAC_ADDR(an->an_node.ni_macaddr),
			size, rate, short_tries, tries, tt,
			sn->stats[size_bin][ndx0].average_tx_time,
			sn->stats[size_bin][ndx0].perfect_tx_time,
			status);
		sn->sample_tt[size_bin] = tt;
		sn->current_sample_ndx[size_bin] = -1;
	}
}

static void
ath_rate_tx_complete(struct ath_softc *sc,
	struct ath_node *an, const struct ath_buf *bf)
{
	struct sample_node *sn = ATH_NODE_SAMPLE(an);
	struct ieee80211com *ic = &sc->sc_ic;
	const struct ath_tx_status *ts = &bf->bf_dsstatus.ds_txstat;
	const struct ath_desc *ds = &bf->bf_desc[0];
	unsigned int final_rate;
	unsigned int short_tries;
	unsigned int long_tries;
	unsigned int frame_size;
	unsigned int mrr;

	final_rate = sc->sc_hwmap[ts->ts_rate &~ HAL_TXSTAT_ALTRATE].ieeerate;
	short_tries = ts->ts_shortretry + 1;
	long_tries = ts->ts_longretry + 1;
	frame_size = ds->ds_ctl0 & 0x0fff; /* low-order 12 bits of ds_ctl0 */

	if (frame_size == 0)
		frame_size = 1500;

	if (sn->num_rates <= 0) {
		DPRINTF(sc, ATH_DEBUG_RATE, "%s: " MAC_FMT " %s no rates yet\n", dev_info,
			MAC_ADDR(an->an_node.ni_macaddr), __func__);
		return;
	}

	mrr = sc->sc_mrretry && !(ic->ic_flags & IEEE80211_F_USEPROT) && ENABLE_MRR;


	if (sc->sc_mrretry && ts->ts_status) {
		/* this packet failed */
		DPRINTF(sc, ATH_DEBUG_RATE, "%s: " MAC_FMT " size %u rate/try %u/%u %u/%u %u/%u %u/%u status %s retries (%u/%u)\n",
			dev_info,
			MAC_ADDR(an->an_node.ni_macaddr),
			bin_to_size(size_to_bin(frame_size)),
			sc->sc_hwmap[MS(ds->ds_ctl3, AR_XmitRate0)].ieeerate,
				MS(ds->ds_ctl2, AR_XmitDataTries0),
			sc->sc_hwmap[MS(ds->ds_ctl3, AR_XmitRate1)].ieeerate,
				MS(ds->ds_ctl2, AR_XmitDataTries1),
			sc->sc_hwmap[MS(ds->ds_ctl3, AR_XmitRate2)].ieeerate,
				MS(ds->ds_ctl2, AR_XmitDataTries2),
			sc->sc_hwmap[MS(ds->ds_ctl3, AR_XmitRate3)].ieeerate,
				MS(ds->ds_ctl2, AR_XmitDataTries3),
			ts->ts_status ? "FAIL" : "OK",
			short_tries, long_tries);
	}

	mrr = sc->sc_mrretry && !(ic->ic_flags & IEEE80211_F_USEPROT) && ENABLE_MRR;


	if (!mrr || !(ts->ts_rate & HAL_TXSTAT_ALTRATE)) {
		/* only one rate was used */
		int ndx = rate_to_ndx(sn, final_rate);
		if ((ndx >= 0) && (ndx < sn->num_rates)) {
			update_stats(sc, an, frame_size,
				ndx, long_tries,
				0, 0,
				0, 0,
				0, 0,
				short_tries, long_tries, ts->ts_status);
		}
	} else {
		unsigned int rate[4], tries[4];
		int ndx[4];
		int finalTSIdx = ts->ts_finaltsi;

		/*
		 * Process intermediate rates that failed.
		 */

		rate[0] = sc->sc_hwmap[MS(ds->ds_ctl3, AR_XmitRate0)].ieeerate;
		tries[0] = MS(ds->ds_ctl2, AR_XmitDataTries0);
		ndx[0] = rate_to_ndx(sn, rate[0]);

		rate[1] = sc->sc_hwmap[MS(ds->ds_ctl3, AR_XmitRate1)].ieeerate;
		tries[1] = MS(ds->ds_ctl2, AR_XmitDataTries1);
		ndx[1] = rate_to_ndx(sn, rate[1]);

		rate[2] = sc->sc_hwmap[MS(ds->ds_ctl3, AR_XmitRate2)].ieeerate;
		tries[2] = MS(ds->ds_ctl2, AR_XmitDataTries2);
		ndx[2] = rate_to_ndx(sn, rate[2]);

		rate[3] = sc->sc_hwmap[MS(ds->ds_ctl3, AR_XmitRate3)].ieeerate;
		tries[3] = MS(ds->ds_ctl2, AR_XmitDataTries3);
		ndx[3] = rate_to_ndx(sn, rate[3]);

#if 0
		DPRINTF(sc, "%s: " MAC_FMT " size %u finaltsidx %u tries %u status %u rate/try %u/%u %u/%u %u/%u %u/%u\n",
			dev_info, MAC_ADDR(an->an_node.ni_macaddr),
			bin_to_size(size_to_bin(frame_size)),
			finalTSIdx,
			long_tries,
			ds->ds_txstat.ts_status,
			rate[0], tries[0],
			rate[1], tries[1],
			rate[2], tries[2],
			rate[3], tries[3]);
#endif

		/* NB: series > 0 are not penalized for failure
		 * based on the try counts under the assumption
		 * that losses are often bursty and since we 
		 * sample higher rates 1 try at a time doing so
		 * may unfairly penalize them.
		 */
		if (tries[0] && ndx[0] >= 0) {
			update_stats(sc, an, frame_size,
				ndx[0], tries[0],
				ndx[1], tries[1],
				ndx[2], tries[2],
				ndx[3], tries[3],
				short_tries, long_tries,