2013-02-11 13:36:09

by Felix Fietkau

[permalink] [raw]
Subject: [PATCH v2 1/3] mac80211/minstrel_ht: show the number of retries for each rate in debugfs

Signed-off-by: Felix Fietkau <[email protected]>
---
net/mac80211/rc80211_minstrel_ht_debugfs.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/net/mac80211/rc80211_minstrel_ht_debugfs.c b/net/mac80211/rc80211_minstrel_ht_debugfs.c
index e788f76..f2b7d26 100644
--- a/net/mac80211/rc80211_minstrel_ht_debugfs.c
+++ b/net/mac80211/rc80211_minstrel_ht_debugfs.c
@@ -38,8 +38,8 @@ minstrel_ht_stats_open(struct inode *inode, struct file *file)

file->private_data = ms;
p = ms->buf;
- p += sprintf(p, "type rate throughput ewma prob this prob "
- "this succ/attempt success attempts\n");
+ 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';
@@ -64,18 +64,19 @@ minstrel_ht_stats_open(struct inode *inode, struct file *file)
*(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) *
+ 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) %8llu %8llu\n",
+ 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,
--
1.8.0.2



2013-02-11 13:57:31

by Christian Lamparter

[permalink] [raw]
Subject: Re: [PATCH v2 3/3] mac80211/minstrel_ht: add support for using CCK rates

On Monday, February 11, 2013 02:36:05 PM Felix Fietkau wrote:
> 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 <[email protected]>
> ---
> static void
> +minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
> + struct ieee80211_supported_band *sband,
> + struct ieee80211_sta *sta)
> +{
> + int i;
> +
> + if (sband->band != IEEE80211_BAND_2GHZ)
> + return;
> +
> + mi->cck_supported = 0;
> + mi->cck_supported_short = 0;
> + for (i = 0; i < 4; i++) {
> + if (!rate_supported(sta, sband->band, mp->cck_rates[i]))
> + continue;

Don't we need to check if the receiver (and the minstrel_ht sender)
supports IEEE80211_HT_CAP_DSSSCCK40 when the phy is in HT40+/- mode?

Regards,
Christian

2013-02-11 13:36:09

by Felix Fietkau

[permalink] [raw]
Subject: [PATCH v2 2/3] mac80211/minstrel_ht: remove the sampling bypass check for the lowest rate

It's more of an unnecessary micro-optimization and it prevents switching
from long-GI to short-GI in HT20/single-stream for the lowest rate

Signed-off-by: Felix Fietkau <[email protected]>
---
net/mac80211/rc80211_minstrel_ht.c | 4 ----
1 file changed, 4 deletions(-)

diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c
index 9f9c453..5bb316a 100644
--- a/net/mac80211/rc80211_minstrel_ht.c
+++ b/net/mac80211/rc80211_minstrel_ht.c
@@ -231,10 +231,6 @@ minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
if (!mr->cur_tp)
continue;

- /* ignore the lowest rate of each single-stream group */
- if (!i && minstrel_mcs_groups[group].streams == 1)
- continue;
-
if ((mr->cur_tp > cur_prob_tp && mr->probability >
MINSTREL_FRAC(3, 4)) || mr->probability > cur_prob) {
mg->max_prob_rate = index;
--
1.8.0.2


2013-02-11 14:10:20

by Felix Fietkau

[permalink] [raw]
Subject: Re: [PATCH v2 3/3] mac80211/minstrel_ht: add support for using CCK rates

On 2013-02-11 2:57 PM, Christian Lamparter wrote:
> On Monday, February 11, 2013 02:36:05 PM Felix Fietkau wrote:
>> 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 <[email protected]>
>> ---
>> static void
>> +minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
>> + struct ieee80211_supported_band *sband,
>> + struct ieee80211_sta *sta)
>> +{
>> + int i;
>> +
>> + if (sband->band != IEEE80211_BAND_2GHZ)
>> + return;
>> +
>> + mi->cck_supported = 0;
>> + mi->cck_supported_short = 0;
>> + for (i = 0; i < 4; i++) {
>> + if (!rate_supported(sta, sband->band, mp->cck_rates[i]))
>> + continue;
>
> Don't we need to check if the receiver (and the minstrel_ht sender)
> supports IEEE80211_HT_CAP_DSSSCCK40 when the phy is in HT40+/- mode?
I don't think this should be handled in the rate control modules, when
mac80211 can easily handle that through the supported rates set (which
seems to be the intention behind this flag in the standard as well).

- Felix


2013-02-11 13:36:10

by Felix Fietkau

[permalink] [raw]
Subject: [PATCH v2 3/3] 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 <[email protected]>
---
net/mac80211/rc80211_minstrel.c | 29 ++++++
net/mac80211/rc80211_minstrel.h | 2 +
net/mac80211/rc80211_minstrel_ht.c | 152 +++++++++++++++++++++++++----
net/mac80211/rc80211_minstrel_ht.h | 5 +-
net/mac80211/rc80211_minstrel_ht_debugfs.c | 109 +++++++++++++--------
5 files changed, 237 insertions(+), 60 deletions(-)

diff --git a/net/mac80211/rc80211_minstrel.c b/net/mac80211/rc80211_minstrel.c
index 8c5acdc..eea45a2 100644
--- a/net/mac80211/rc80211_minstrel.c
+++ b/net/mac80211/rc80211_minstrel.c
@@ -494,6 +494,33 @@ minstrel_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta)
kfree(mi);
}

+static void
+minstrel_init_cck_rates(struct minstrel_priv *mp)
+{
+ static const int bitrates[4] = { 10, 20, 55, 110 };
+ struct ieee80211_supported_band *sband;
+ int i, j;
+
+ sband = mp->hw->wiphy->bands[IEEE80211_BAND_2GHZ];
+ if (!sband)
+ return;
+
+ for (i = 0, j = 0; i < sband->n_bitrates; i++) {
+ struct ieee80211_rate *rate = &sband->bitrates[i];
+
+ if (rate->flags & IEEE80211_RATE_ERP_G)
+ continue;
+
+ for (j = 0; j < ARRAY_SIZE(bitrates); j++) {
+ if (rate->bitrate != bitrates[j])
+ continue;
+
+ mp->cck_rates[j] = i;
+ break;
+ }
+ }
+}
+
static void *
minstrel_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
{
@@ -539,6 +566,8 @@ minstrel_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
S_IRUGO | S_IWUGO, debugfsdir, &mp->fixed_rate_idx);
#endif

+ minstrel_init_cck_rates(mp);
+
return mp;
}

diff --git a/net/mac80211/rc80211_minstrel.h b/net/mac80211/rc80211_minstrel.h
index 5d278ec..5ecf757 100644
--- a/net/mac80211/rc80211_minstrel.h
+++ b/net/mac80211/rc80211_minstrel.h
@@ -79,6 +79,8 @@ struct minstrel_priv {
unsigned int lookaround_rate;
unsigned int lookaround_rate_mrr;

+ u8 cck_rates[4];
+
#ifdef CONFIG_MAC80211_DEBUGFS
/*
* enable fixed rate processing per RC
diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c
index 5bb316a..ff65539 100644
--- a/net/mac80211/rc80211_minstrel_ht.c
+++ b/net/mac80211/rc80211_minstrel_ht.c
@@ -1,5 +1,5 @@
/*
- * Copyright (C) 2010 Felix Fietkau <[email protected]>
+ * Copyright (C) 2010-2013 Felix Fietkau <[email protected]>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
@@ -63,6 +63,30 @@
} \
}

+#define CCK_DURATION(_bitrate, _short, _len) \
+ (10 /* SIFS */ + \
+ (_short ? 72 + 24 : 144 + 48 ) + \
+ (8 * (_len + 4) * 10) / (_bitrate))
+
+#define CCK_ACK_DURATION(_bitrate, _short) \
+ (CCK_DURATION((_bitrate > 10 ? 20 : 10), false, 60) + \
+ CCK_DURATION(_bitrate, _short, AVG_PKT_SIZE))
+
+#define CCK_DURATION_LIST(_short) \
+ CCK_ACK_DURATION(10, _short), \
+ CCK_ACK_DURATION(20, _short), \
+ CCK_ACK_DURATION(55, _short), \
+ CCK_ACK_DURATION(110, _short)
+
+#define CCK_GROUP \
+ { \
+ .streams = 0, \
+ .duration = { \
+ CCK_DURATION_LIST(false), \
+ CCK_DURATION_LIST(true) \
+ } \
+ }
+
/*
* To enable sufficiently targeted rate sampling, MCS rates are divided into
* groups, based on the number of streams and flags (HT40, SGI) that they
@@ -95,8 +119,13 @@ const struct mcs_group minstrel_mcs_groups[] = {
#if MINSTREL_MAX_STREAMS >= 3
MCS_GROUP(3, 1, 1),
#endif
+
+ /* must be last */
+ CCK_GROUP
};

+#define MINSTREL_CCK_GROUP (ARRAY_SIZE(minstrel_mcs_groups) - 1)
+
static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES];

/*
@@ -119,6 +148,29 @@ minstrel_ht_get_group_idx(struct ieee80211_tx_rate *rate)
!!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH));
}

+struct minstrel_rate_stats *
+minstrel_ht_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
+ struct ieee80211_tx_rate *rate)
+{
+ int group, idx;
+
+ if (rate->flags & IEEE80211_TX_RC_MCS) {
+ group = minstrel_ht_get_group_idx(rate);
+ idx = rate->idx % MCS_GROUP_RATES;
+ } else {
+ group = MINSTREL_CCK_GROUP;
+
+ for (idx = 0; idx <= ARRAY_SIZE(mp->cck_rates); idx++)
+ if (rate->idx == mp->cck_rates[idx])
+ break;
+
+ /* short preamble */
+ if (!(mi->groups[group].supported & BIT(idx)))
+ idx += 4;
+ }
+ return &mi->groups[group].rates[idx];
+}
+
static inline struct minstrel_rate_stats *
minstrel_get_ratestats(struct minstrel_ht_sta *mi, int index)
{
@@ -159,7 +211,7 @@ static void
minstrel_ht_calc_tp(struct minstrel_ht_sta *mi, int group, int rate)
{
struct minstrel_rate_stats *mr;
- unsigned int usecs;
+ unsigned int usecs = 0;

mr = &mi->groups[group].rates[rate];

@@ -168,7 +220,9 @@ minstrel_ht_calc_tp(struct minstrel_ht_sta *mi, int group, int rate)
return;
}

- usecs = mi->overhead / MINSTREL_TRUNC(mi->avg_ampdu_len);
+ if (group != MINSTREL_CCK_GROUP)
+ usecs = mi->overhead / MINSTREL_TRUNC(mi->avg_ampdu_len);
+
usecs += minstrel_mcs_groups[group].duration[rate];
mr->cur_tp = MINSTREL_TRUNC((1000000 / usecs) * mr->probability);
}
@@ -293,7 +347,7 @@ minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
}

static bool
-minstrel_ht_txstat_valid(struct ieee80211_tx_rate *rate)
+minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct ieee80211_tx_rate *rate)
{
if (rate->idx < 0)
return false;
@@ -301,7 +355,13 @@ minstrel_ht_txstat_valid(struct ieee80211_tx_rate *rate)
if (!rate->count)
return false;

- return !!(rate->flags & IEEE80211_TX_RC_MCS);
+ if (rate->flags & IEEE80211_TX_RC_MCS);
+ return true;
+
+ return rate->idx == mp->cck_rates[0] ||
+ rate->idx == mp->cck_rates[1] ||
+ rate->idx == mp->cck_rates[2] ||
+ rate->idx == mp->cck_rates[3];
}

static void
@@ -386,7 +446,6 @@ minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
struct minstrel_rate_stats *rate, *rate2;
struct minstrel_priv *mp = priv;
bool last;
- int group;
int i;

if (!msp->is_ht)
@@ -415,13 +474,12 @@ minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
mi->sample_packets += info->status.ampdu_len;

- last = !minstrel_ht_txstat_valid(&ar[0]);
+ last = !minstrel_ht_txstat_valid(mp, &ar[0]);
for (i = 0; !last; i++) {
last = (i == IEEE80211_TX_MAX_RATES - 1) ||
- !minstrel_ht_txstat_valid(&ar[i + 1]);
+ !minstrel_ht_txstat_valid(mp, &ar[i + 1]);

- group = minstrel_ht_get_group_idx(&ar[i]);
- rate = &mi->groups[group].rates[ar[i].idx % 8];
+ rate = minstrel_ht_get_stats(mp, mi, &ar[i]);

if (last)
rate->success += info->status.ampdu_ack_len;
@@ -447,7 +505,8 @@ minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,

if (time_after(jiffies, mi->stats_update + (mp->update_interval / 2 * HZ) / 1000)) {
minstrel_ht_update_stats(mp, mi);
- if (!(info->flags & IEEE80211_TX_CTL_AMPDU))
+ if (!(info->flags & IEEE80211_TX_CTL_AMPDU) &&
+ mi->max_prob_rate / MCS_GROUP_RATES != MINSTREL_CCK_GROUP)
minstrel_aggr_check(sta, skb);
}
}
@@ -463,6 +522,7 @@ minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
unsigned int ctime = 0;
unsigned int t_slot = 9; /* FIXME */
unsigned int ampdu_len = MINSTREL_TRUNC(mi->avg_ampdu_len);
+ unsigned int overhead = 0, overhead_rtscts = 0;

mr = minstrel_get_ratestats(mi, index);
if (mr->probability < MINSTREL_FRAC(1, 10)) {
@@ -484,9 +544,14 @@ minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
ctime += (t_slot * cw) >> 1;
cw = min((cw << 1) | 1, mp->cw_max);

+ if (index / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) {
+ overhead = mi->overhead;
+ overhead_rtscts = mi->overhead_rtscts;
+ }
+
/* Total TX time for data and Contention after first 2 tries */
- tx_time = ctime + 2 * (mi->overhead + tx_time_data);
- tx_time_rtscts = ctime + 2 * (mi->overhead_rtscts + tx_time_data);
+ tx_time = ctime + 2 * (overhead + tx_time_data);
+ tx_time_rtscts = ctime + 2 * (overhead_rtscts + tx_time_data);

/* See how many more tries we can fit inside segment size */
do {
@@ -495,8 +560,8 @@ minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
cw = min((cw << 1) | 1, mp->cw_max);

/* Total TX time after this try */
- tx_time += ctime + mi->overhead + tx_time_data;
- tx_time_rtscts += ctime + mi->overhead_rtscts + tx_time_data;
+ tx_time += ctime + overhead + tx_time_data;
+ tx_time_rtscts += ctime + overhead_rtscts + tx_time_data;

if (tx_time_rtscts < mp->segment_size)
mr->retry_count_rtscts++;
@@ -526,9 +591,16 @@ minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
else
rate->count = mr->retry_count;

- rate->flags = IEEE80211_TX_RC_MCS | group->flags;
+ rate->flags = 0;
if (rtscts)
rate->flags |= IEEE80211_TX_RC_USE_RTS_CTS;
+
+ if (index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) {
+ rate->idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)];
+ return;
+ }
+
+ rate->flags |= IEEE80211_TX_RC_MCS | group->flags;
rate->idx = index % MCS_GROUP_RATES + (group->streams - 1) * MCS_GROUP_RATES;
}

@@ -592,6 +664,22 @@ minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
}

static void
+minstrel_ht_check_cck_shortpreamble(struct minstrel_priv *mp,
+ struct minstrel_ht_sta *mi, bool val)
+{
+ u8 supported = mi->groups[MINSTREL_CCK_GROUP].supported;
+
+ if (!supported || !mi->cck_supported_short)
+ return;
+
+ if (supported & (mi->cck_supported_short << (val * 4)))
+ return;
+
+ supported ^= mi->cck_supported_short | (mi->cck_supported_short << 4);
+ mi->groups[MINSTREL_CCK_GROUP].supported = supported;
+}
+
+static void
minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
struct ieee80211_tx_rate_control *txrc)
{
@@ -610,6 +698,7 @@ minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
return mac80211_minstrel.get_rate(priv, sta, &msp->legacy, txrc);

info->flags |= mi->tx_flags;
+ minstrel_ht_check_cck_shortpreamble(mp, mi, txrc->short_preamble);

/* Don't use EAPOL frames for sampling on non-mrr hw */
if (mp->hw->max_rates == 1 &&
@@ -683,6 +772,30 @@ minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
}

static void
+minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
+ struct ieee80211_supported_band *sband,
+ struct ieee80211_sta *sta)
+{
+ int i;
+
+ if (sband->band != IEEE80211_BAND_2GHZ)
+ return;
+
+ mi->cck_supported = 0;
+ mi->cck_supported_short = 0;
+ for (i = 0; i < 4; i++) {
+ if (!rate_supported(sta, sband->band, mp->cck_rates[i]))
+ continue;
+
+ mi->cck_supported |= BIT(i);
+ if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE)
+ mi->cck_supported_short |= BIT(i);
+ }
+
+ mi->groups[MINSTREL_CCK_GROUP].supported = mi->cck_supported;
+}
+
+static void
minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
struct ieee80211_sta *sta, void *priv_sta)
{
@@ -702,7 +815,7 @@ minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
goto use_legacy;

BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) !=
- MINSTREL_MAX_STREAMS * MINSTREL_STREAM_GROUPS);
+ MINSTREL_MAX_STREAMS * MINSTREL_STREAM_GROUPS + 1);

msp->is_ht = true;
memset(mi, 0, sizeof(*mi));
@@ -738,6 +851,11 @@ minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
u16 req = 0;

mi->groups[i].supported = 0;
+ if (i == MINSTREL_CCK_GROUP) {
+ minstrel_ht_update_cck(mp, mi, sband, sta);
+ continue;
+ }
+
if (minstrel_mcs_groups[i].flags & IEEE80211_TX_RC_SHORT_GI) {
if (minstrel_mcs_groups[i].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
req |= IEEE80211_HT_CAP_SGI_40;
diff --git a/net/mac80211/rc80211_minstrel_ht.h b/net/mac80211/rc80211_minstrel_ht.h
index 462d2b2..302dbd5 100644
--- a/net/mac80211/rc80211_minstrel_ht.h
+++ b/net/mac80211/rc80211_minstrel_ht.h
@@ -107,8 +107,11 @@ struct minstrel_ht_sta {
/* current MCS group to be sampled */
u8 sample_group;

+ u8 cck_supported;
+ u8 cck_supported_short;
+
/* MCS rate group info and statistics */
- struct minstrel_mcs_group_data groups[MINSTREL_MAX_STREAMS * MINSTREL_STREAM_GROUPS];
+ struct minstrel_mcs_group_data groups[MINSTREL_MAX_STREAMS * MINSTREL_STREAM_GROUPS + 1];
};

struct minstrel_ht_sta_priv {
diff --git a/net/mac80211/rc80211_minstrel_ht_debugfs.c b/net/mac80211/rc80211_minstrel_ht_debugfs.c
index f2b7d26..df44a5a 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),
--
1.8.0.2


2013-02-11 21:51:45

by Johannes Berg

[permalink] [raw]
Subject: Re: [PATCH v2 3/3] mac80211/minstrel_ht: add support for using CCK rates

Applied patches 1 and 2 but this one had too many smatch complaints:


> #define CCK_GROUP \
> { \
> .streams = 0, \
> .duration = { \
> CCK_DURATION_LIST(false), \
> CCK_DURATION_LIST(true) \
> } \
> }

This seems to have caused smatch to complain, because after having

#define MCS_GROUP(_streams, _sgi, _ht40) \
[GROUP_IDX(_streams, _sgi, _ht40)] = { \

it couldn't prove that the CCK went into slot 12. Are you sure they go
there for sure, with the different initialization?

> +struct minstrel_rate_stats *
> +minstrel_ht_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
> + struct ieee80211_tx_rate *rate)
> +{
> + int group, idx;
> +
> + if (rate->flags & IEEE80211_TX_RC_MCS) {
> + group = minstrel_ht_get_group_idx(rate);
> + idx = rate->idx % MCS_GROUP_RATES;
> + } else {
> + group = MINSTREL_CCK_GROUP;
> +
> + for (idx = 0; idx <= ARRAY_SIZE(mp->cck_rates); idx++)

should be < rather than <=?

> + if (rate->flags & IEEE80211_TX_RC_MCS);
> + return true;

ho humm ...

johannes


2013-02-11 14:31:34

by Johannes Berg

[permalink] [raw]
Subject: Re: [PATCH v2 3/3] mac80211/minstrel_ht: add support for using CCK rates

On Mon, 2013-02-11 at 15:10 +0100, Felix Fietkau wrote:
> On 2013-02-11 2:57 PM, Christian Lamparter wrote:
> > On Monday, February 11, 2013 02:36:05 PM Felix Fietkau wrote:
> >> 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 <[email protected]>
> >> ---
> >> static void
> >> +minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
> >> + struct ieee80211_supported_band *sband,
> >> + struct ieee80211_sta *sta)
> >> +{
> >> + int i;
> >> +
> >> + if (sband->band != IEEE80211_BAND_2GHZ)
> >> + return;
> >> +
> >> + mi->cck_supported = 0;
> >> + mi->cck_supported_short = 0;
> >> + for (i = 0; i < 4; i++) {
> >> + if (!rate_supported(sta, sband->band, mp->cck_rates[i]))
> >> + continue;
> >
> > Don't we need to check if the receiver (and the minstrel_ht sender)
> > supports IEEE80211_HT_CAP_DSSSCCK40 when the phy is in HT40+/- mode?
> I don't think this should be handled in the rate control modules, when
> mac80211 can easily handle that through the supported rates set (which
> seems to be the intention behind this flag in the standard as well).

Patches welcome. This corner of the spec doesn't seem to be implemented
at all :)

johannes