Date: Wed, 31 Oct 2012 06:35:50 +0000 (UTC) From: Adrian Chadd <adrian@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r242392 - head/sys/dev/ath/ath_rate/sample Message-ID: <201210310635.q9V6Zo2Y068832@svn.freebsd.org>
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Author: adrian Date: Wed Oct 31 06:35:50 2012 New Revision: 242392 URL: http://svn.freebsd.org/changeset/base/242392 Log: I've had some feedback that CCK rates are more reliable than MCS 0 in some very degenerate conditions. However, until ath_rate_form_aggr() is taught to not form aggregates if ANY selected rate is non-MCS, this can't yet be enabled. So, just add a comment. Modified: head/sys/dev/ath/ath_rate/sample/sample.c Modified: head/sys/dev/ath/ath_rate/sample/sample.c ============================================================================== --- head/sys/dev/ath/ath_rate/sample/sample.c Wed Oct 31 06:27:58 2012 (r242391) +++ head/sys/dev/ath/ath_rate/sample/sample.c Wed Oct 31 06:35:50 2012 (r242392) @@ -272,12 +272,29 @@ pick_sample_rate(struct sample_softc *ss continue; } + /* + * The following code stops trying to sample + * non-MCS rates when speaking to an MCS node. + * However, at least for CCK rates in 2.4GHz mode, + * the non-MCS rates MAY actually provide better + * PER at the very far edge of reception. + * + * However! Until ath_rate_form_aggr() grows + * some logic to not form aggregates if the + * selected rate is non-MCS, this won't work. + * + * So don't disable this code until you've taught + * ath_rate_form_aggr() to drop out if any of + * the selected rates are non-MCS. + */ +#if 1 /* if the node is HT and the rate isn't HT, don't bother sample */ if ((an->an_node.ni_flags & IEEE80211_NODE_HT) && (rt->info[rix].phy != IEEE80211_T_HT)) { mask &= ~((uint64_t) 1<<rix); goto nextrate; } +#endif /* this bit-rate is always worse than the current one */ if (sn->stats[size_bin][rix].perfect_tx_time > current_tt) {
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