2012-06-25 05:15:45

by Sven Eckelmann

[permalink] [raw]
Subject: [PATCH] ath9k: raise aggregation limit to 64k for HT IBSS

mac80211 adds stations in HT IBSS as soon as a frame comes by,
even if the HT capabilities are not known yet (they are often
received later, e.g. in beacons). So far, ampdu factor/density
are only calculated when the station is initially added.

This patch changes this to update ampdu factor/density settings
when starting a blockack session.

Using this patch, we had performance boosts from 60 to 150 MBit/s
between two 2x2 Atheros devices in 5 GHz HT IBSS mode.

Signed-off-by: Sven Eckelmann <[email protected]>
Signed-off-by: Simon Wunderlich <[email protected]>
---
This is a resent of an RFC ([email protected],
but now marked as patch). No changes were made because no problems were found
during the review.

drivers/net/wireless/ath/ath9k/ath9k.h | 1 +
drivers/net/wireless/ath/ath9k/main.c | 6 ++++--
drivers/net/wireless/ath/ath9k/xmit.c | 12 ++++++++++++
3 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index f72c4a3..fe39eb4 100644
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -722,6 +722,7 @@ extern int ath9k_modparam_nohwcrypt;
extern int led_blink;
extern bool is_ath9k_unloaded;

+u8 ath9k_parse_mpdudensity(u8 mpdudensity);
irqreturn_t ath_isr(int irq, void *dev);
int ath9k_init_device(u16 devid, struct ath_softc *sc,
const struct ath_bus_ops *bus_ops);
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index 85f9ab4..e2e6958 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -19,7 +19,7 @@
#include "ath9k.h"
#include "btcoex.h"

-static u8 parse_mpdudensity(u8 mpdudensity)
+u8 ath9k_parse_mpdudensity(u8 mpdudensity)
{
/*
* 802.11n D2.0 defined values for "Minimum MPDU Start Spacing":
@@ -320,6 +320,7 @@ static void ath_node_attach(struct ath_softc *sc, struct ieee80211_sta *sta,
struct ieee80211_vif *vif)
{
struct ath_node *an;
+ u8 density;
an = (struct ath_node *)sta->drv_priv;

#ifdef CONFIG_ATH9K_DEBUGFS
@@ -334,7 +335,8 @@ static void ath_node_attach(struct ath_softc *sc, struct ieee80211_sta *sta,
ath_tx_node_init(sc, an);
an->maxampdu = 1 << (IEEE80211_HT_MAX_AMPDU_FACTOR +
sta->ht_cap.ampdu_factor);
- an->mpdudensity = parse_mpdudensity(sta->ht_cap.ampdu_density);
+ density = ath9k_parse_mpdudensity(sta->ht_cap.ampdu_density);
+ an->mpdudensity = density;
}
}

diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
index 8d83060..cafb4a0 100644
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -1165,6 +1165,7 @@ int ath_tx_aggr_start(struct ath_softc *sc, struct ieee80211_sta *sta,
{
struct ath_atx_tid *txtid;
struct ath_node *an;
+ u8 density;

an = (struct ath_node *)sta->drv_priv;
txtid = ATH_AN_2_TID(an, tid);
@@ -1172,6 +1173,17 @@ int ath_tx_aggr_start(struct ath_softc *sc, struct ieee80211_sta *sta,
if (txtid->state & (AGGR_CLEANUP | AGGR_ADDBA_COMPLETE))
return -EAGAIN;

+ /* update ampdu factor/density, they may have changed. This may happen
+ * in HT IBSS when a beacon with HT-info is received after the station
+ * has already been added.
+ */
+ if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_HT) {
+ an->maxampdu = 1 << (IEEE80211_HT_MAX_AMPDU_FACTOR +
+ sta->ht_cap.ampdu_factor);
+ density = ath9k_parse_mpdudensity(sta->ht_cap.ampdu_density);
+ an->mpdudensity = density;
+ }
+
txtid->state |= AGGR_ADDBA_PROGRESS;
txtid->paused = true;
*ssn = txtid->seq_start = txtid->seq_next;
--
1.7.10