svn commit: r218448 - head/sys/dev/ath/ath_rate/sample

Adrian Chadd adrian at FreeBSD.org
Tue Feb 8 18:31:28 UTC 2011


Author: adrian
Date: Tue Feb  8 18:31:28 2011
New Revision: 218448
URL: http://svn.freebsd.org/changeset/base/218448

Log:
  Commit some missing bits to the sample rate module to (more) correctly calculate 802.11n packet duration.
  
  This doesn't yet take into account HT40 packet durations as the node info
  (needed to know if it's a HT20 or HT40 node) isn't available everywhere
  it needs to be.

Modified:
  head/sys/dev/ath/ath_rate/sample/sample.h

Modified: head/sys/dev/ath/ath_rate/sample/sample.h
==============================================================================
--- head/sys/dev/ath/ath_rate/sample/sample.h	Tue Feb  8 17:04:52 2011	(r218447)
+++ head/sys/dev/ath/ath_rate/sample/sample.h	Tue Feb  8 18:31:28 2011	(r218448)
@@ -114,7 +114,7 @@ struct sample_node {
  * Calculate the transmit duration of a frame.
  */
 static unsigned calc_usecs_unicast_packet(struct ath_softc *sc,
-				int length, 
+				int length,
 				int rix, int short_retries, int long_retries) {
 	const HAL_RATE_TABLE *rt = sc->sc_currates;
 	struct ifnet *ifp = sc->sc_ifp;
@@ -153,6 +153,11 @@ static unsigned calc_usecs_unicast_packe
 		t_sifs = 8;
 		t_difs = 28;
 		break;
+	case IEEE80211_T_HT:
+		t_slot = 9;
+		t_sifs = 8;
+		t_difs = 28;
+		break;
 	case IEEE80211_T_DS:
 		/* fall through to default */
 	default:
@@ -172,7 +177,6 @@ static unsigned calc_usecs_unicast_packe
 			cts = 1;
 
 		cix = rt->info[sc->sc_protrix].controlRate;
-
 	}
 
 	if (0 /*length > ic->ic_rtsthreshold */) {
@@ -192,8 +196,9 @@ static unsigned calc_usecs_unicast_packe
 		if (rts)		/* SIFS + CTS */
 			ctsduration += rt->info[cix].spAckDuration;
 
-		ctsduration += ath_hal_computetxtime(sc->sc_ah,
-						     rt, length, rix, AH_TRUE);
+		/* XXX assumes short preamble */
+		/* XXX assumes HT/20; the node info isn't yet available here */
+		ctsduration += ath_hal_pkt_txtime(sc->sc_ah, rt, length, rix, 0, AH_TRUE);
 
 		if (cts)	/* SIFS + ACK */
 			ctsduration += rt->info[cix].spAckDuration;
@@ -201,9 +206,12 @@ static unsigned calc_usecs_unicast_packe
 		tt += (short_retries + 1) * ctsduration;
 	}
 	tt += t_difs;
+
+	/* XXX assumes short preamble */
+	/* XXX assumes HT/20; the node info isn't yet available here */
+	tt += (long_retries+1)*ath_hal_pkt_txtime(sc->sc_ah, rt, length, rix, 0, AH_TRUE);
 	tt += (long_retries+1)*(t_sifs + rt->info[rix].spAckDuration);
-	tt += (long_retries+1)*ath_hal_computetxtime(sc->sc_ah, rt, length, 
-						rix, AH_TRUE);
+
 	for (x = 0; x <= short_retries + long_retries; x++) {
 		cw = MIN(WIFI_CW_MAX, (cw + 1) * 2);
 		tt += (t_slot * cw/2);


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