This enables Adaptive Noise Immunity (ANI) on ath9k.
ANI is as algorithm designed to minimize the detrimental
effects of time-varying interferences. This should
help with throughput in noisy environments. To use
ANI we re-enable the MIB interrupt. Since ANI works
on a timer and updates the noise floor we take
advantage of this and also report a non-static noise
floor now to mac80211.
Signed-off-by: Sujith Manoharan <Sujith.Manoharan@xxxxxxxxxxx>
Signed-off-by: Jouni Malinen <Jouni.Malinen@xxxxxxxxxxx>
Signed-off-by: Luis R. Rodriguez <lrodriguez@xxxxxxxxxxx>
---
I've tested this on x86 and x86_64
drivers/net/wireless/ath9k/ath9k.h | 2 +-
drivers/net/wireless/ath9k/core.c | 129 ++++++++++++++++++++++++++++++++++--
drivers/net/wireless/ath9k/core.h | 25 +++++++
drivers/net/wireless/ath9k/hw.c | 35 ++++++++--
drivers/net/wireless/ath9k/main.c | 18 +++++-
drivers/net/wireless/ath9k/recv.c | 13 +---
6 files changed, 197 insertions(+), 25 deletions(-)
diff --git a/drivers/net/wireless/ath9k/ath9k.h b/drivers/net/wireless/ath9k/ath9k.h
index 0e897c2..accace5 100644
--- a/drivers/net/wireless/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath9k/ath9k.h
@@ -854,7 +854,7 @@ bool ath9k_hw_calibrate(struct ath_hal *ah,
u8 rxchainmask,
bool longcal,
bool *isCalDone);
-int16_t ath9k_hw_getchan_noise(struct ath_hal *ah,
+s16 ath9k_hw_getchan_noise(struct ath_hal *ah,
struct ath9k_channel *chan);
void ath9k_hw_write_associd(struct ath_hal *ah, const u8 *bssid,
u16 assocId);
diff --git a/drivers/net/wireless/ath9k/core.c b/drivers/net/wireless/ath9k/core.c
index 5af7dfb..c5033f6 100644
--- a/drivers/net/wireless/ath9k/core.c
+++ b/drivers/net/wireless/ath9k/core.c
@@ -490,6 +490,122 @@ void ath_update_chainmask(struct ath_softc *sc, int is_ht)
__func__, sc->sc_tx_chainmask, sc->sc_rx_chainmask);
}
+/*******/
+/* ANI */
+/*******/
+
+/*
+ * This routine performs the periodic noise floor calibration function
+ * that is used to adjust and optimize the chip performance. This
+ * takes environmental changes (location, temperature) into account.
+ * When the task is complete, it reschedules itself depending on the
+ * appropriate interval that was calculated.
+ */
+
+static void ath_ani_calibrate(unsigned long data)
+{
+ struct ath_softc *sc;
+ struct ath_hal *ah;
+ bool longcal = false;
+ bool shortcal = false;
+ bool aniflag = false;
+ unsigned int timestamp = jiffies_to_msecs(jiffies);
+ u32 cal_interval;
+
+ sc = (struct ath_softc *)data;
+ ah = sc->sc_ah;
+
+ /*
+ * don't calibrate when we're scanning.
+ * we are most likely not on our home channel.
+ */
+ if (sc->rx_filter & FIF_BCN_PRBRESP_PROMISC)
+ return;
+
+ /* Long calibration runs independently of short calibration. */
+ if ((timestamp - sc->sc_ani.sc_longcal_timer) >= ATH_LONG_CALINTERVAL) {
+ longcal = true;
+ DPRINTF(sc, ATH_DBG_ANI, "%s: longcal @%lu\n",
+ __func__, jiffies);
+ sc->sc_ani.sc_longcal_timer = timestamp;
+ }
+
+ /* Short calibration applies only while sc_caldone is false */
+ if (!sc->sc_ani.sc_caldone) {
+ if ((timestamp - sc->sc_ani.sc_shortcal_timer) >=
+ ATH_SHORT_CALINTERVAL) {
+ shortcal = true;
+ DPRINTF(sc, ATH_DBG_ANI, "%s: shortcal @%lu\n",
+ __func__, jiffies);
+ sc->sc_ani.sc_shortcal_timer = timestamp;
+ sc->sc_ani.sc_resetcal_timer = timestamp;
+ }
+ } else {
+ if ((timestamp - sc->sc_ani.sc_resetcal_timer) >=
+ ATH_RESTART_CALINTERVAL) {
+ ath9k_hw_reset_calvalid(ah, ah->ah_curchan,
+ &sc->sc_ani.sc_caldone);
+ if (sc->sc_ani.sc_caldone)
+ sc->sc_ani.sc_resetcal_timer = timestamp;
+ }
+ }
+
+ /* Verify whether we must check ANI */
+ if ((timestamp - sc->sc_ani.sc_checkani_timer) >=
+ ATH_ANI_POLLINTERVAL) {
+ aniflag = true;
+ sc->sc_ani.sc_checkani_timer = timestamp;
+ }
+
+ /* Skip all processing if there's nothing to do. */
+ if (longcal || shortcal || aniflag) {
+ /* Call ANI routine if necessary */
+ if (aniflag)
+ ath9k_hw_ani_monitor(ah, &sc->sc_halstats,
+ ah->ah_curchan);
+
+ /* Perform calibration if necessary */
+ if (longcal || shortcal) {
+ bool iscaldone = false;
+
+ if (ath9k_hw_calibrate(ah, ah->ah_curchan,
+ sc->sc_rx_chainmask, longcal,
+ &iscaldone)) {
+ if (longcal)
+ sc->sc_ani.sc_noise_floor =
+ ath9k_hw_getchan_noise(ah,
+ ah->ah_curchan);
+
+ DPRINTF(sc, ATH_DBG_ANI,
+ "%s: calibrate chan %u/%x nf: %d\n",
+ __func__,
+ ah->ah_curchan->channel,
+ ah->ah_curchan->channelFlags,
+ sc->sc_ani.sc_noise_floor);
+ } else {
+ DPRINTF(sc, ATH_DBG_ANY,
+ "%s: calibrate chan %u/%x failed\n",
+ __func__,
+ ah->ah_curchan->channel,
+ ah->ah_curchan->channelFlags);
+ }
+ sc->sc_ani.sc_caldone = iscaldone;
+ }
+ }
+
+ /*
+ * Set timer interval based on previous results.
+ * The interval must be the shortest necessary to satisfy ANI,
+ * short calibration and long calibration.
+ */
+
+ cal_interval = ATH_ANI_POLLINTERVAL;
+ if (!sc->sc_ani.sc_caldone)
+ cal_interval = min(cal_interval, (u32)ATH_SHORT_CALINTERVAL);
+
+ mod_timer(&sc->sc_ani.timer, jiffies + msecs_to_jiffies(cal_interval));
+}
+
/******************/
/* VAP management */
/******************/
@@ -676,12 +792,6 @@ int ath_open(struct ath_softc *sc, struct ath9k_channel *initial_chan)
if (ah->ah_caps.hw_caps & ATH9K_HW_CAP_HT)
sc->sc_imask |= ATH9K_INT_CST;
- /* Note: We disable MIB interrupts for now as we don't yet
- * handle processing ANI, otherwise you will get an interrupt
- * storm after about 7 hours of usage making the system unusable
- * with huge latency. Once we do have ANI processing included
- * we can re-enable this interrupt. */
-#if 0
/*
* Enable MIB interrupts when there are hardware phy counters.
* Note we only do this (at the moment) for station mode.
@@ -690,7 +800,6 @@ int ath_open(struct ath_softc *sc, struct ath9k_channel *initial_chan)
((sc->sc_ah->ah_opmode == ATH9K_M_STA) ||
(sc->sc_ah->ah_opmode == ATH9K_M_IBSS)))
sc->sc_imask |= ATH9K_INT_MIB;
-#endif
/*
* Some hardware processes the TIM IE and fires an
* interrupt when the TIM bit is set. For hardware
@@ -991,6 +1100,10 @@ int ath_init(u16 devid, struct ath_softc *sc)
}
sc->sc_ah = ah;
+ /* Initializes the noise floor to a reasonable default value.
+ * Later on this will be updated during ANI processing. */
+ sc->sc_ani.sc_noise_floor = ATH_DEFAULT_NOISE_FLOOR;
+
/* Get the hardware key cache size. */
sc->sc_keymax = ah->ah_caps.keycache_size;
if (sc->sc_keymax > ATH_KEYMAX) {
@@ -1098,6 +1211,8 @@ int ath_init(u16 devid, struct ath_softc *sc)
goto bad2;
}
+ setup_timer(&sc->sc_ani.timer, ath_ani_calibrate, (unsigned long)sc);
+
sc->sc_rc = ath_rate_attach(ah);
if (sc->sc_rc == NULL) {
error = -EIO;
diff --git a/drivers/net/wireless/ath9k/core.h b/drivers/net/wireless/ath9k/core.h
index 5b4f1c4..cb3e61e 100644
--- a/drivers/net/wireless/ath9k/core.h
+++ b/drivers/net/wireless/ath9k/core.h
@@ -800,6 +800,28 @@ void ath_slow_ant_div(struct ath_antdiv *antdiv,
struct ath_rx_status *rx_stats);
void ath_setdefantenna(void *sc, u32 antenna);
+/*******/
+/* ANI */
+/*******/
+
+/* ANI values for STA only.
+ FIXME: Add appropriate values for AP later */
+
+#define ATH_ANI_POLLINTERVAL 100 /* 100 milliseconds between ANI poll */
+#define ATH_SHORT_CALINTERVAL 1000 /* 1 second between calibrations */
+#define ATH_LONG_CALINTERVAL 30000 /* 30 seconds between calibrations */
+#define ATH_RESTART_CALINTERVAL 1200000 /* 20 minutes between calibrations */
+
+struct ath_ani {
+ bool sc_caldone;
+ int16_t sc_noise_floor;
+ unsigned int sc_longcal_timer;
+ unsigned int sc_shortcal_timer;
+ unsigned int sc_resetcal_timer;
+ unsigned int sc_checkani_timer;
+ struct timer_list timer;
+};
+
/********************/
/* LED Control */
/********************/
@@ -1028,6 +1050,9 @@ struct ath_softc {
/* Rfkill */
struct ath_rfkill rf_kill;
+
+ /* ANI */
+ struct ath_ani sc_ani;
};
int ath_init(u16 devid, struct ath_softc *sc);
diff --git a/drivers/net/wireless/ath9k/hw.c b/drivers/net/wireless/ath9k/hw.c
index 272c758..62e44a0 100644
--- a/drivers/net/wireless/ath9k/hw.c
+++ b/drivers/net/wireless/ath9k/hw.c
@@ -329,7 +329,7 @@ static void ath9k_hw_set_defaults(struct ath_hal *ah)
ah->ah_config.ofdm_trig_high = 500;
ah->ah_config.cck_trig_high = 200;
ah->ah_config.cck_trig_low = 100;
- ah->ah_config.enable_ani = 0;
+ ah->ah_config.enable_ani = 1;
ah->ah_config.noise_immunity_level = 4;
ah->ah_config.ofdm_weaksignal_det = 1;
ah->ah_config.cck_weaksignal_thr = 0;
@@ -8405,23 +8405,48 @@ u32 ath9k_hw_mhz2ieee(struct ath_hal *ah, u32 freq, u32 flags)
}
}
-int16_t
+/* We can tune this as we go by monitoring really low values */
+#define ATH9K_NF_TOO_LOW -60
+
+/* AR5416 may return very high value (like -31 dBm), in those cases the nf
+ * is incorrect and we should use the static NF value. Later we can try to
+ * find out why they are reporting these values */
+static bool ath9k_hw_nf_in_range(struct ath_hal *ah, s16 nf)
+{
+ if (nf > ATH9K_NF_TOO_LOW) {
+ DPRINTF(ah->ah_sc, ATH_DBG_NF_CAL,
+ "%s: noise floor value detected (%d) is "
+ "lower than what we think is a "
+ "reasonable value (%d)\n",
+ __func__, nf, ATH9K_NF_TOO_LOW);
+ return false;
+ }
+ return true;
+}
+
+s16
ath9k_hw_getchan_noise(struct ath_hal *ah, struct ath9k_channel *chan)
{
struct ath9k_channel *ichan;
+ s16 nf;
ichan = ath9k_regd_check_channel(ah, chan);
if (ichan == NULL) {
DPRINTF(ah->ah_sc, ATH_DBG_NF_CAL,
"%s: invalid channel %u/0x%x; no mapping\n",
__func__, chan->channel, chan->channelFlags);
- return 0;
+ return ATH_DEFAULT_NOISE_FLOOR;
}
if (ichan->rawNoiseFloor == 0) {
enum wireless_mode mode = ath9k_hw_chan2wmode(ah, chan);
- return NOISE_FLOOR[mode];
+ nf = NOISE_FLOOR[mode];
} else
- return ichan->rawNoiseFloor;
+ nf = ichan->rawNoiseFloor;
+
+ if (!ath9k_hw_nf_in_range(ah, nf))
+ nf = ATH_DEFAULT_NOISE_FLOOR;
+
+ return nf;
}
bool ath9k_hw_set_tsfadjust(struct ath_hal *ah, u32 setting)
diff --git a/drivers/net/wireless/ath9k/main.c b/drivers/net/wireless/ath9k/main.c
index 2caba44..7472699 100644
--- a/drivers/net/wireless/ath9k/main.c
+++ b/drivers/net/wireless/ath9k/main.c
@@ -274,10 +274,12 @@ static void ath9k_rx_prepare(struct ath_softc *sc,
rx_status->mactime = status->tsf;
rx_status->band = curchan->band;
rx_status->freq = curchan->center_freq;
- rx_status->noise = ATH_DEFAULT_NOISE_FLOOR;
+ rx_status->noise = sc->sc_ani.sc_noise_floor;
rx_status->signal = rx_status->noise + status->rssi;
rx_status->rate_idx = ath_rate2idx(sc, (status->rateKbps / 100));
rx_status->antenna = status->antenna;
+
+ /* XXX Fix me, 64 cannot be the max rssi value, rigure it out */
rx_status->qual = status->rssi * 100 / 64;
if (status->flags & ATH_RX_MIC_ERROR)
@@ -427,6 +429,11 @@ static void ath9k_bss_assoc_info(struct ath_softc *sc,
ath_rate_newstate(sc, avp);
/* Update ratectrl about the new state */
ath_rc_node_update(hw, avp->rc_node);
+
+ /* Start ANI */
+ mod_timer(&sc->sc_ani.timer,
+ jiffies + msecs_to_jiffies(ATH_ANI_POLLINTERVAL));
+
} else {
DPRINTF(sc, ATH_DBG_CONFIG,
"%s: Bss Info DISSOC\n", __func__);
@@ -1173,6 +1180,13 @@ static int ath9k_add_interface(struct ieee80211_hw *hw,
return error;
}
+ if (conf->type == NL80211_IFTYPE_AP) {
+ /* TODO: is this a suitable place to start ANI for AP mode? */
+ /* Start ANI */
+ mod_timer(&sc->sc_ani.timer,
+ jiffies + msecs_to_jiffies(ATH_ANI_POLLINTERVAL));
+ }
+
return 0;
}
@@ -1195,6 +1209,8 @@ static void ath9k_remove_interface(struct ieee80211_hw *hw,
#ifdef CONFIG_SLOW_ANT_DIV
ath_slow_ant_div_stop(&sc->sc_antdiv);
#endif
+ /* Stop ANI */
+ del_timer_sync(&sc->sc_ani.timer);
/* Update ratectrl */
ath_rate_newstate(sc, avp);
diff --git a/drivers/net/wireless/ath9k/recv.c b/drivers/net/wireless/ath9k/recv.c
index f4be5d1..4983402 100644
--- a/drivers/net/wireless/ath9k/recv.c
+++ b/drivers/net/wireless/ath9k/recv.c
@@ -999,20 +999,11 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush)
rx_status.flags |= ATH_RX_SHORT_GI;
}
- /* sc->sc_noise_floor is only available when the station
+ /* sc_noise_floor is only available when the station
attaches to an AP, so we use a default value
if we are not yet attached. */
-
- /* XXX we should use either sc->sc_noise_floor or
- * ath_hal_getChanNoise(ah, &sc->sc_curchan)
- * to calculate the noise floor.
- * However, the value returned by ath_hal_getChanNoise
- * seems to be incorrect (-31dBm on the last test),
- * so we will use a hard-coded value until we
- * figure out what is going on.
- */
rx_status.abs_rssi =
- ds->ds_rxstat.rs_rssi + ATH_DEFAULT_NOISE_FLOOR;
+ ds->ds_rxstat.rs_rssi + sc->sc_ani.sc_noise_floor;
pci_dma_sync_single_for_cpu(sc->pdev,
bf->bf_buf_addr,
--
1.5.6.rc2.15.g457bb.dirty
--
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