]> pilppa.com Git - linux-2.6-omap-h63xx.git/commitdiff
ath9k: enable ANI to help with noisy environments
authorLuis R. Rodriguez <lrodriguez@atheros.com>
Fri, 3 Oct 2008 22:45:27 +0000 (15:45 -0700)
committerJohn W. Linville <linville@tuxdriver.com>
Mon, 6 Oct 2008 22:14:56 +0000 (18:14 -0400)
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@atheros.com>
Signed-off-by: Jouni Malinen <Jouni.Malinen@Atheros.com>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
drivers/net/wireless/ath9k/ath9k.h
drivers/net/wireless/ath9k/core.c
drivers/net/wireless/ath9k/core.h
drivers/net/wireless/ath9k/hw.c
drivers/net/wireless/ath9k/main.c
drivers/net/wireless/ath9k/recv.c

index 0e897c276858e5912783b1abb3599efbcbc5f51f..accace5f7efb9d809e962c4a32d2120e57182d60 100644 (file)
@@ -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);
index 5af7dfbd423d9cbd03401f3bd80c8bc9405e34e4..c5033f6f42acd3c6ddf4cf7d00835adf9c9b665e 100644 (file)
@@ -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;
index 5b4f1c48a6186123c2b0df57c34ef85bb9e606c5..cb3e61e57c4d9a82218c6c7220fdef0f26fa3e77 100644 (file)
@@ -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);
index 272c758166091033b4b64889830434143a140cf6..62e44a0ef996211a61255f16cd799e10860a4f49 100644 (file)
@@ -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)
index 2caba440316728ec75e1c4f85849978394c7deef..74726990d59e0ae1851fe0d587032f355dabecbf 100644 (file)
@@ -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);
index f4be5d11c9d516f4341396db7d8e03f798b40659..4983402af559871f8ed526480794235dfc37959e 100644 (file)
@@ -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,