mac80211/minstrel_ht: add support for using CCK rates

When MCS rates start to get bad in 2.4 GHz because of long range or
strong interference, CCK rates can be a lot more robust.

This patch adds a pseudo MCS group containing CCK rates (long preamble
in the lower 4 slots, short preamble in the upper slots).

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
[make minstrel_ht_get_stats static]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 67 insertions, 42 deletions

diff --git a/net/mac80211/rc80211_minstrel_ht_debugfs.c b/net/mac80211/rc80211_minstrel_ht_debugfs.c
index f2b7d26370f..df44a5ad827 100644
--- a/net/mac80211/rc80211_minstrel_ht_debugfs.c
+++ b/net/mac80211/rc80211_minstrel_ht_debugfs.c
@@ -15,13 +15,76 @@
 #include "rc80211_minstrel.h"
 #include "rc80211_minstrel_ht.h"
 
+static char *
+minstrel_ht_stats_dump(struct minstrel_ht_sta *mi, int i, char *p)
+{
+	unsigned int max_mcs = MINSTREL_MAX_STREAMS * MINSTREL_STREAM_GROUPS;
+	const struct mcs_group *mg;
+	unsigned int j, tp, prob, eprob;
+	char htmode = '2';
+	char gimode = 'L';
+
+	if (!mi->groups[i].supported)
+		return p;
+
+	mg = &minstrel_mcs_groups[i];
+	if (mg->flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
+		htmode = '4';
+	if (mg->flags & IEEE80211_TX_RC_SHORT_GI)
+		gimode = 'S';
+
+	for (j = 0; j < MCS_GROUP_RATES; j++) {
+		struct minstrel_rate_stats *mr = &mi->groups[i].rates[j];
+		static const int bitrates[4] = { 10, 20, 55, 110 };
+		int idx = i * MCS_GROUP_RATES + j;
+
+		if (!(mi->groups[i].supported & BIT(j)))
+			continue;
+
+		if (i == max_mcs)
+			p += sprintf(p, "CCK/%cP   ", j < 4 ? 'L' : 'S');
+		else
+			p += sprintf(p, "HT%c0/%cGI ", htmode, gimode);
+
+		*(p++) = (idx == mi->max_tp_rate) ? 'T' : ' ';
+		*(p++) = (idx == mi->max_tp_rate2) ? 't' : ' ';
+		*(p++) = (idx == mi->max_prob_rate) ? 'P' : ' ';
+
+		if (i == max_mcs) {
+			int r = bitrates[j % 4];
+			p += sprintf(p, " %2u.%1uM", r / 10, r % 10);
+		} else {
+			p += sprintf(p, " MCS%-2u", (mg->streams - 1) *
+					 MCS_GROUP_RATES + j);
+		}
+
+		tp = mr->cur_tp / 10;
+		prob = MINSTREL_TRUNC(mr->cur_prob * 1000);
+		eprob = MINSTREL_TRUNC(mr->probability * 1000);
+
+		p += sprintf(p, "      %6u.%1u   %6u.%1u    %6u.%1u    "
+				"%3u            %3u(%3u)  %8llu    %8llu\n",
+				tp / 10, tp % 10,
+				eprob / 10, eprob % 10,
+				prob / 10, prob % 10,
+				mr->retry_count,
+				mr->last_success,
+				mr->last_attempts,
+				(unsigned long long)mr->succ_hist,
+				(unsigned long long)mr->att_hist);
+	}
+
+	return p;
+}
+
 static int
 minstrel_ht_stats_open(struct inode *inode, struct file *file)
 {
 	struct minstrel_ht_sta_priv *msp = inode->i_private;
 	struct minstrel_ht_sta *mi = &msp->ht;
 	struct minstrel_debugfs_info *ms;
-	unsigned int i, j, tp, prob, eprob;
+	unsigned int i;
+	unsigned int max_mcs = MINSTREL_MAX_STREAMS * MINSTREL_STREAM_GROUPS;
 	char *p;
 	int ret;
 
@@ -40,49 +103,11 @@ minstrel_ht_stats_open(struct inode *inode, struct file *file)
 	p = ms->buf;
 	p += sprintf(p, "type         rate     throughput  ewma prob   this prob  "
 			"retry   this succ/attempt   success    attempts\n");
-	for (i = 0; i < MINSTREL_MAX_STREAMS * MINSTREL_STREAM_GROUPS; i++) {
-		char htmode = '2';
-		char gimode = 'L';
-
-		if (!mi->groups[i].supported)
-			continue;
-
-		if (minstrel_mcs_groups[i].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
-			htmode = '4';
-		if (minstrel_mcs_groups[i].flags & IEEE80211_TX_RC_SHORT_GI)
-			gimode = 'S';
 
-		for (j = 0; j < MCS_GROUP_RATES; j++) {
-			struct minstrel_rate_stats *mr = &mi->groups[i].rates[j];
-			int idx = i * MCS_GROUP_RATES + j;
+	p = minstrel_ht_stats_dump(mi, max_mcs, p);
+	for (i = 0; i < max_mcs; i++)
+		p = minstrel_ht_stats_dump(mi, i, p);
 
-			if (!(mi->groups[i].supported & BIT(j)))
-				continue;
-
-			p += sprintf(p, "HT%c0/%cGI ", htmode, gimode);
-
-			*(p++) = (idx == mi->max_tp_rate) ? 'T' : ' ';
-			*(p++) = (idx == mi->max_tp_rate2) ? 't' : ' ';
-			*(p++) = (idx == mi->max_prob_rate) ? 'P' : ' ';
-			p += sprintf(p, " MCS%-2u", (minstrel_mcs_groups[i].streams - 1) *
-					MCS_GROUP_RATES + j);
-
-			tp = mr->cur_tp / 10;
-			prob = MINSTREL_TRUNC(mr->cur_prob * 1000);
-			eprob = MINSTREL_TRUNC(mr->probability * 1000);
-
-			p += sprintf(p, "      %6u.%1u   %6u.%1u    %6u.%1u    "
-					"%3u            %3u(%3u)  %8llu    %8llu\n",
-					tp / 10, tp % 10,
-					eprob / 10, eprob % 10,
-					prob / 10, prob % 10,
-					mr->retry_count,
-					mr->last_success,
-					mr->last_attempts,
-					(unsigned long long)mr->succ_hist,
-					(unsigned long long)mr->att_hist);
-		}
-	}
 	p += sprintf(p, "\nTotal packet count::    ideal %d      "
 			"lookaround %d\n",
 			max(0, (int) mi->total_packets - (int) mi->sample_packets),