From f12140c04ca49ea34c448b1bd8aa40fb9411690c Mon Sep 17 00:00:00 2001 From: Karl Beldan Date: Mon, 11 Nov 2013 13:10:49 +0100 Subject: [PATCH] mac80211: minstrel_ht: do not sample unsupported rates ATM minstrel_ht does not check whether a sampling rate is supported. Unsupported rates attempts can trigger when there are holes in bitfields of supported MCSes belonging to the same group (e.g many devices are MCS32 capable without MCS33->39 capable, also we systematically have a hole for CCK rates). Drop any attempts to sample unsupported rates, as suggested by Felix. This is not a problem in minstrel which fills a per STA sample table with only supported rates (though only at init). Signed-off-by: Karl Beldan Signed-off-by: Johannes Berg --- net/mac80211/rc80211_minstrel_ht.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c index e66e9f9..b91655a 100644 --- a/net/mac80211/rc80211_minstrel_ht.c +++ b/net/mac80211/rc80211_minstrel_ht.c @@ -700,12 +700,16 @@ minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) if (!mi->sample_tries) return -1; - mg = &mi->groups[mi->sample_group]; + sample_group = mi->sample_group; + mg = &mi->groups[sample_group]; sample_idx = sample_table[mg->column][mg->index]; + minstrel_next_sample_idx(mi); + + if (!(mg->supported & BIT(sample_idx))) + return -1; + mr = &mg->rates[sample_idx]; - sample_group = mi->sample_group; sample_idx += sample_group * MCS_GROUP_RATES; - minstrel_next_sample_idx(mi); /* * Sampling might add some overhead (RTS, no aggregation) -- 2.7.4