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iwlwifi: A-MPDU Tx activation by load measures
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This patch gives a heuristic for activation of the A-MPDU Tx.
As the rate scaling is rate aware, it now also measures estimated load, and
sends A-MPDU activation after a threshold has been met.

Signed-off-by: Ron Rindjunsky <ron.rindjunsky@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
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Ron Rindjunsky authored and John W. Linville committed Feb 29, 2008
1 parent 9955643 commit 0c11b4d
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Showing 5 changed files with 199 additions and 487 deletions.
204 changes: 186 additions & 18 deletions drivers/net/wireless/iwlwifi/iwl-4965-rs.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -83,7 +83,7 @@ struct iwl4965_rate_scale_data {
/**
* struct iwl4965_scale_tbl_info -- tx params and success history for all rates
*
* There are two of these in struct iwl_rate_scale_priv,
* There are two of these in struct iwl4965_lq_sta,
* one for "active", and one for "search".
*/
struct iwl4965_scale_tbl_info {
Expand All @@ -98,8 +98,23 @@ struct iwl4965_scale_tbl_info {
struct iwl4965_rate_scale_data win[IWL_RATE_COUNT]; /* rate histories */
};

#ifdef CONFIG_IWL4965_HT

struct iwl4965_traffic_load {
unsigned long time_stamp; /* age of the oldest statistics */
u32 packet_count[TID_QUEUE_MAX_SIZE]; /* packet count in this time
* slice */
u32 total; /* total num of packets during the
* last TID_MAX_TIME_DIFF */
u8 queue_count; /* number of queues that has
* been used since the last cleanup */
u8 head; /* start of the circular buffer */
};

#endif /* CONFIG_IWL4965_HT */

/**
* struct iwl_rate_scale_priv -- driver's rate scaling private structure
* struct iwl4965_lq_sta -- driver's rate scaling private structure
*
* Pointer to this gets passed back and forth between driver and mac80211.
*/
Expand Down Expand Up @@ -136,9 +151,16 @@ struct iwl4965_lq_sta {

struct iwl4965_link_quality_cmd lq;
struct iwl4965_scale_tbl_info lq_info[LQ_SIZE]; /* "active", "search" */
#ifdef CONFIG_IWL4965_HT
struct iwl4965_traffic_load load[TID_MAX_LOAD_COUNT];
u8 tx_agg_tid_en;
#endif
#ifdef CONFIG_MAC80211_DEBUGFS
struct dentry *rs_sta_dbgfs_scale_table_file;
struct dentry *rs_sta_dbgfs_stats_table_file;
#ifdef CONFIG_IWL4965_HT
struct dentry *rs_sta_dbgfs_tx_agg_tid_en_file;
#endif
struct iwl4965_rate dbg_fixed;
struct iwl4965_priv *drv;
#endif
Expand Down Expand Up @@ -269,6 +291,135 @@ static void rs_rate_scale_clear_window(struct iwl4965_rate_scale_data *window)
window->stamp = 0;
}

#ifdef CONFIG_IWL4965_HT
/*
* removes the old data from the statistics. All data that is older than
* TID_MAX_TIME_DIFF, will be deleted.
*/
static void rs_tl_rm_old_stats(struct iwl4965_traffic_load *tl, u32 curr_time)
{
/* The oldest age we want to keep */
u32 oldest_time = curr_time - TID_MAX_TIME_DIFF;

while (tl->queue_count &&
(tl->time_stamp < oldest_time)) {
tl->total -= tl->packet_count[tl->head];
tl->packet_count[tl->head] = 0;
tl->time_stamp += TID_QUEUE_CELL_SPACING;
tl->queue_count--;
tl->head++;
if (tl->head >= TID_QUEUE_MAX_SIZE)
tl->head = 0;
}
}

/*
* increment traffic load value for tid and also remove
* any old values if passed the certain time period
*/
static void rs_tl_add_packet(struct iwl4965_lq_sta *lq_data, u8 tid)
{
u32 curr_time = jiffies_to_msecs(jiffies);
u32 time_diff;
s32 index;
struct iwl4965_traffic_load *tl = NULL;

if (tid >= TID_MAX_LOAD_COUNT)
return;

tl = &lq_data->load[tid];

curr_time -= curr_time % TID_ROUND_VALUE;

/* Happens only for the first packet. Initialize the data */
if (!(tl->queue_count)) {
tl->total = 1;
tl->time_stamp = curr_time;
tl->queue_count = 1;
tl->head = 0;
tl->packet_count[0] = 1;
return;
}

time_diff = TIME_WRAP_AROUND(tl->time_stamp, curr_time);
index = time_diff / TID_QUEUE_CELL_SPACING;

/* The history is too long: remove data that is older than */
/* TID_MAX_TIME_DIFF */
if (index >= TID_QUEUE_MAX_SIZE)
rs_tl_rm_old_stats(tl, curr_time);

index = (tl->head + index) % TID_QUEUE_MAX_SIZE;
tl->packet_count[index] = tl->packet_count[index] + 1;
tl->total = tl->total + 1;

if ((index + 1) > tl->queue_count)
tl->queue_count = index + 1;
}

/*
get the traffic load value for tid
*/
static u32 rs_tl_get_load(struct iwl4965_lq_sta *lq_data, u8 tid)
{
u32 curr_time = jiffies_to_msecs(jiffies);
u32 time_diff;
s32 index;
struct iwl4965_traffic_load *tl = NULL;

if (tid >= TID_MAX_LOAD_COUNT)
return 0;

tl = &(lq_data->load[tid]);

curr_time -= curr_time % TID_ROUND_VALUE;

if (!(tl->queue_count))
return 0;

time_diff = TIME_WRAP_AROUND(tl->time_stamp, curr_time);
index = time_diff / TID_QUEUE_CELL_SPACING;

/* The history is too long: remove data that is older than */
/* TID_MAX_TIME_DIFF */
if (index >= TID_QUEUE_MAX_SIZE)
rs_tl_rm_old_stats(tl, curr_time);

return tl->total;
}

static void rs_tl_turn_on_agg_for_tid(struct iwl4965_priv *priv,
struct iwl4965_lq_sta *lq_data, u8 tid,
struct sta_info *sta)
{
unsigned long state;
DECLARE_MAC_BUF(mac);

spin_lock_bh(&sta->ampdu_mlme.ampdu_tx);
state = sta->ampdu_mlme.tid_tx[tid].state;
spin_unlock_bh(&sta->ampdu_mlme.ampdu_tx);

if (state == HT_AGG_STATE_IDLE &&
rs_tl_get_load(lq_data, tid) > IWL_AGG_LOAD_THRESHOLD) {
IWL_DEBUG_HT("Starting Tx agg: STA: %s tid: %d\n",
print_mac(mac, sta->addr), tid);
ieee80211_start_tx_ba_session(priv->hw, sta->addr, tid);
}
}

static void rs_tl_turn_on_agg(struct iwl4965_priv *priv, u8 tid,
struct iwl4965_lq_sta *lq_data,
struct sta_info *sta)
{
if ((tid < TID_MAX_LOAD_COUNT))
rs_tl_turn_on_agg_for_tid(priv, lq_data, tid, sta);
else if (tid == IWL_AGG_ALL_TID)
for (tid = 0; tid < TID_MAX_LOAD_COUNT; tid++)
rs_tl_turn_on_agg_for_tid(priv, lq_data, tid, sta);
}

#endif /* CONFIG_IWLWIFI_HT */

/**
* rs_collect_tx_data - Update the success/failure sliding window
*
Expand Down Expand Up @@ -1134,7 +1285,7 @@ static int rs_switch_to_mimo(struct iwl4965_priv *priv,
return 0;
#else
return -1;
#endif /*CONFIG_IWL4965_HT */
#endif /*CONFIG_IWL4965_HT */
}

/*
Expand Down Expand Up @@ -1197,7 +1348,7 @@ static int rs_switch_to_siso(struct iwl4965_priv *priv,
#else
return -1;

#endif /*CONFIG_IWL4965_HT */
#endif /*CONFIG_IWL4965_HT */
}

/*
Expand Down Expand Up @@ -1354,6 +1505,7 @@ static int rs_move_siso_to_other(struct iwl4965_priv *priv,
break;
case IWL_SISO_SWITCH_GI:
IWL_DEBUG_HT("LQ: SISO SWITCH TO GI\n");

memcpy(search_tbl, tbl, sz);
search_tbl->action = 0;
if (search_tbl->is_SGI)
Expand Down Expand Up @@ -1419,6 +1571,7 @@ static int rs_move_mimo_to_other(struct iwl4965_priv *priv,
case IWL_MIMO_SWITCH_ANTENNA_B:
IWL_DEBUG_HT("LQ: MIMO SWITCH TO SISO\n");


/* Set up new search table for SISO */
memcpy(search_tbl, tbl, sz);
search_tbl->lq_type = LQ_SISO;
Expand Down Expand Up @@ -1603,6 +1756,10 @@ static void rs_rate_scale_perform(struct iwl4965_priv *priv,
u8 active_tbl = 0;
u8 done_search = 0;
u16 high_low;
#ifdef CONFIG_IWL4965_HT
u8 tid = MAX_TID_COUNT;
__le16 *qc;
#endif

IWL_DEBUG_RATE("rate scale calculate new rate for skb\n");

Expand All @@ -1623,6 +1780,13 @@ static void rs_rate_scale_perform(struct iwl4965_priv *priv,
}
lq_sta = (struct iwl4965_lq_sta *)sta->rate_ctrl_priv;

#ifdef CONFIG_IWL4965_HT
qc = ieee80211_get_qos_ctrl(hdr);
if (qc) {
tid = (u8)(le16_to_cpu(*qc) & 0xf);
rs_tl_add_packet(lq_sta, tid);
}
#endif
/*
* Select rate-scale / modulation-mode table to work with in
* the rest of this function: "search" if searching for better
Expand Down Expand Up @@ -1943,15 +2107,14 @@ static void rs_rate_scale_perform(struct iwl4965_priv *priv,
* mode for a while before next round of mode comparisons. */
if (lq_sta->enable_counter &&
(lq_sta->action_counter >= IWL_ACTION_LIMIT)) {
#ifdef CONFIG_IWL4965_HT_AGG
/* If appropriate, set up aggregation! */
if ((lq_sta->last_tpt > TID_AGG_TPT_THREHOLD) &&
(priv->lq_mngr.agg_ctrl.auto_agg)) {
priv->lq_mngr.agg_ctrl.tid_retry =
TID_ALL_SPECIFIED;
schedule_work(&priv->agg_work);
#ifdef CONFIG_IWL4965_HT
if ((lq_sta->last_tpt > IWL_AGG_TPT_THREHOLD) &&
(lq_sta->tx_agg_tid_en & (1 << tid)) &&
(tid != MAX_TID_COUNT)) {
IWL_DEBUG_HT("try to aggregate tid %d\n", tid);
rs_tl_turn_on_agg(priv, tid, lq_sta, sta);
}
#endif /*CONFIG_IWL4965_HT_AGG */
#endif /*CONFIG_IWL4965_HT */
lq_sta->action_counter = 0;
rs_set_stay_in_table(0, lq_sta);
}
Expand Down Expand Up @@ -2209,6 +2372,8 @@ static void rs_rate_init(void *priv_rate, void *priv_sta,
IWL_DEBUG_HT("SISO RATE 0x%X MIMO RATE 0x%X\n",
lq_sta->active_siso_rate,
lq_sta->active_mimo_rate);
/* as default allow aggregation for all tids */
lq_sta->tx_agg_tid_en = IWL_AGG_ALL_TID;
#endif /*CONFIG_IWL4965_HT*/
#ifdef CONFIG_MAC80211_DEBUGFS
lq_sta->drv = priv;
Expand Down Expand Up @@ -2352,12 +2517,6 @@ static void rs_clear(void *priv_rate)
IWL_DEBUG_RATE("enter\n");

priv->lq_mngr.lq_ready = 0;
#ifdef CONFIG_IWL4965_HT
#ifdef CONFIG_IWL4965_HT_AGG
if (priv->lq_mngr.agg_ctrl.granted_ba)
iwl4965_turn_off_agg(priv, TID_ALL_SPECIFIED);
#endif /*CONFIG_IWL4965_HT_AGG */
#endif /* CONFIG_IWL4965_HT */

IWL_DEBUG_RATE("leave\n");
}
Expand Down Expand Up @@ -2524,13 +2683,22 @@ static void rs_add_debugfs(void *priv, void *priv_sta,
lq_sta->rs_sta_dbgfs_stats_table_file =
debugfs_create_file("rate_stats_table", 0600, dir,
lq_sta, &rs_sta_dbgfs_stats_table_ops);
#ifdef CONFIG_IWL4965_HT
lq_sta->rs_sta_dbgfs_tx_agg_tid_en_file =
debugfs_create_u8("tx_agg_tid_enable", 0600, dir,
&lq_sta->tx_agg_tid_en);
#endif

}

static void rs_remove_debugfs(void *priv, void *priv_sta)
{
struct iwl4965_lq_sta *lq_sta = priv_sta;
debugfs_remove(lq_sta->rs_sta_dbgfs_scale_table_file);
debugfs_remove(lq_sta->rs_sta_dbgfs_stats_table_file);
#ifdef CONFIG_IWL4965_HT
debugfs_remove(lq_sta->rs_sta_dbgfs_tx_agg_tid_en_file);
#endif
}
#endif

Expand Down
12 changes: 12 additions & 0 deletions drivers/net/wireless/iwlwifi/iwl-4965-rs.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -212,6 +212,18 @@ enum {

#define LQ_SIZE 2 /* 2 mode tables: "Active" and "Search" */

/* load per tid defines for A-MPDU activation */
#define IWL_AGG_TPT_THREHOLD 0
#define IWL_AGG_LOAD_THRESHOLD 10
#define IWL_AGG_ALL_TID 0xff
#define TID_QUEUE_CELL_SPACING 50 /*mS */
#define TID_QUEUE_MAX_SIZE 20
#define TID_ROUND_VALUE 5 /* mS */
#define TID_MAX_LOAD_COUNT 8

#define TID_MAX_TIME_DIFF ((TID_QUEUE_MAX_SIZE - 1) * TID_QUEUE_CELL_SPACING)
#define TIME_WRAP_AROUND(x, y) (((y) > (x)) ? (y) - (x) : (0-(x)) + (y))

extern const struct iwl4965_rate_info iwl4965_rates[IWL_RATE_COUNT];

enum iwl4965_table_type {
Expand Down
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