ath9k: improve stuck beacon recovery and noise floor handling. significantly improves stability under strong interference in ap mode

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@22460 3c298f89-4303-0410-b956-a3cf2f4a3e73

4 files changed, 306 insertions, 0 deletions

diff --git a/package/mac80211/patches/540-ath9k_bstuck_debug.patch b/package/mac80211/patches/540-ath9k_bstuck_debug.patch
new file mode 100644
index 000000000..b2d44c5bb
--- /dev/null
+++ b/package/mac80211/patches/540-ath9k_bstuck_debug.patch
@@ -0,0 +1,43 @@
+--- a/drivers/net/wireless/ath/debug.h
++++ b/drivers/net/wireless/ath/debug.h
+@@ -36,6 +36,7 @@
+  * @ATH_DBG_PS: power save processing
+  * @ATH_DBG_HWTIMER: hardware timer handling
+  * @ATH_DBG_BTCOEX: bluetooth coexistance
++ * @ATH_DBG_BSTUCK: stuck beacons
+  * @ATH_DBG_ANY: enable all debugging
+  *
+  * The debug level is used to control the amount and type of debugging output
+@@ -60,6 +61,7 @@ enum ATH_DEBUG {
+ 	ATH_DBG_HWTIMER		= 0x00001000,
+ 	ATH_DBG_BTCOEX		= 0x00002000,
+ 	ATH_DBG_WMI		= 0x00004000,
++	ATH_DBG_BSTUCK		= 0x00008000,
+ 	ATH_DBG_ANY		= 0xffffffff
+ };
+ 
+--- a/drivers/net/wireless/ath/ath9k/beacon.c
++++ b/drivers/net/wireless/ath/ath9k/beacon.c
+@@ -359,11 +359,11 @@ void ath_beacon_tasklet(unsigned long da
+ 		sc->beacon.bmisscnt++;
+ 
+ 		if (sc->beacon.bmisscnt < BSTUCK_THRESH) {
+-			ath_print(common, ATH_DBG_BEACON,
++			ath_print(common, ATH_DBG_BSTUCK,
+ 				  "missed %u consecutive beacons\n",
+ 				  sc->beacon.bmisscnt);
+ 		} else if (sc->beacon.bmisscnt >= BSTUCK_THRESH) {
+-			ath_print(common, ATH_DBG_BEACON,
++			ath_print(common, ATH_DBG_BSTUCK,
+ 				  "beacon is officially stuck\n");
+ 			sc->sc_flags |= SC_OP_TSF_RESET;
+ 			ath_reset(sc, false);
+@@ -373,7 +373,7 @@ void ath_beacon_tasklet(unsigned long da
+ 	}
+ 
+ 	if (sc->beacon.bmisscnt != 0) {
+-		ath_print(common, ATH_DBG_BEACON,
++		ath_print(common, ATH_DBG_BSTUCK,
+ 			  "resume beacon xmit after %u misses\n",
+ 			  sc->beacon.bmisscnt);
+ 		sc->beacon.bmisscnt = 0;
diff --git a/package/mac80211/patches/541-ath9k_nf_validate.patch b/package/mac80211/patches/541-ath9k_nf_validate.patch
new file mode 100644
index 000000000..7e3cb350f
--- /dev/null
+++ b/package/mac80211/patches/541-ath9k_nf_validate.patch
@@ -0,0 +1,101 @@
+--- a/drivers/net/wireless/ath/ath9k/calib.c
++++ b/drivers/net/wireless/ath/ath9k/calib.c
+@@ -19,8 +19,7 @@
+ 
+ /* Common calibration code */
+ 
+-/* We can tune this as we go by monitoring really low values */
+-#define ATH9K_NF_TOO_LOW	-60
++#define ATH9K_NF_TOO_HIGH	-60
+ 
+ static int16_t ath9k_hw_get_nf_hist_mid(int16_t *nfCalBuffer)
+ {
+@@ -45,11 +44,35 @@ static int16_t ath9k_hw_get_nf_hist_mid(
+ 	return nfval;
+ }
+ 
+-static void ath9k_hw_update_nfcal_hist_buffer(struct ath9k_nfcal_hist *h,
++static struct ath_nf_limits *ath9k_hw_get_nf_limits(struct ath_hw *ah,
++						    struct ath9k_channel *chan)
++{
++	struct ath_nf_limits *limit;
++
++	if (!chan || IS_CHAN_2GHZ(chan))
++		limit = &ah->nf_2g;
++	else
++		limit = &ah->nf_5g;
++
++	return limit;
++}
++
++static s16 ath9k_hw_get_default_nf(struct ath_hw *ah,
++				   struct ath9k_channel *chan)
++{
++	return ath9k_hw_get_nf_limits(ah, chan)->nominal;
++}
++
++
++static void ath9k_hw_update_nfcal_hist_buffer(struct ath_hw *ah,
++					      struct ath9k_nfcal_hist *h,
+ 					      int16_t *nfarray)
+ {
++	struct ath_nf_limits *limit;
+ 	int i;
+ 
++	limit = ath9k_hw_get_nf_limits(ah, ah->curchan);
++
+ 	for (i = 0; i < NUM_NF_READINGS; i++) {
+ 		h[i].nfCalBuffer[h[i].currIndex] = nfarray[i];
+ 
+@@ -63,6 +86,9 @@ static void ath9k_hw_update_nfcal_hist_b
+ 			h[i].privNF =
+ 				ath9k_hw_get_nf_hist_mid(h[i].nfCalBuffer);
+ 		}
++
++		if (h[i].privNF > limit->max)
++			h[i].privNF = limit->max;
+ 	}
+ }
+ 
+@@ -104,19 +130,6 @@ void ath9k_hw_reset_calibration(struct a
+ 	ah->cal_samples = 0;
+ }
+ 
+-static s16 ath9k_hw_get_default_nf(struct ath_hw *ah,
+-				   struct ath9k_channel *chan)
+-{
+-	struct ath_nf_limits *limit;
+-
+-	if (!chan || IS_CHAN_2GHZ(chan))
+-		limit = &ah->nf_2g;
+-	else
+-		limit = &ah->nf_5g;
+-
+-	return limit->nominal;
+-}
+-
+ /* This is done for the currently configured channel */
+ bool ath9k_hw_reset_calvalid(struct ath_hw *ah)
+ {
+@@ -277,10 +290,10 @@ static void ath9k_hw_nf_sanitize(struct 
+ 			  "NF calibrated [%s] [chain %d] is %d\n",
+ 			  (i >= 3 ? "ext" : "ctl"), i % 3, nf[i]);
+ 
+-		if (nf[i] > limit->max) {
++		if (nf[i] > ATH9K_NF_TOO_HIGH) {
+ 			ath_print(common, ATH_DBG_CALIBRATE,
+ 				  "NF[%d] (%d) > MAX (%d), correcting to MAX",
+-				  i, nf[i], limit->max);
++				  i, nf[i], ATH9K_NF_TOO_HIGH);
+ 			nf[i] = limit->max;
+ 		} else if (nf[i] < limit->min) {
+ 			ath_print(common, ATH_DBG_CALIBRATE,
+@@ -326,7 +339,7 @@ bool ath9k_hw_getnf(struct ath_hw *ah, s
+ 
+ 	h = caldata->nfCalHist;
+ 	caldata->nfcal_pending = false;
+-	ath9k_hw_update_nfcal_hist_buffer(h, nfarray);
++	ath9k_hw_update_nfcal_hist_buffer(ah, h, nfarray);
+ 	caldata->rawNoiseFloor = h[0].privNF;
+ 	return true;
+ }
diff --git a/package/mac80211/patches/542-ath9k_bstuck_nf_calibrate.patch b/package/mac80211/patches/542-ath9k_bstuck_nf_calibrate.patch
new file mode 100644
index 000000000..35db2cba3
--- /dev/null
+++ b/package/mac80211/patches/542-ath9k_bstuck_nf_calibrate.patch
@@ -0,0 +1,127 @@
+--- a/drivers/net/wireless/ath/ath9k/beacon.c
++++ b/drivers/net/wireless/ath/ath9k/beacon.c
+@@ -362,6 +362,7 @@ void ath_beacon_tasklet(unsigned long da
+ 			ath_print(common, ATH_DBG_BSTUCK,
+ 				  "missed %u consecutive beacons\n",
+ 				  sc->beacon.bmisscnt);
++			ath9k_hw_bstuck_nfcal(ah);
+ 		} else if (sc->beacon.bmisscnt >= BSTUCK_THRESH) {
+ 			ath_print(common, ATH_DBG_BSTUCK,
+ 				  "beacon is officially stuck\n");
+--- a/drivers/net/wireless/ath/ath9k/calib.c
++++ b/drivers/net/wireless/ath/ath9k/calib.c
+@@ -65,12 +65,16 @@ static s16 ath9k_hw_get_default_nf(struc
+ 
+ 
+ static void ath9k_hw_update_nfcal_hist_buffer(struct ath_hw *ah,
+-					      struct ath9k_nfcal_hist *h,
++					      struct ath9k_hw_cal_data *cal,
+ 					      int16_t *nfarray)
+ {
++	struct ath_common *common = ath9k_hw_common(ah);
+ 	struct ath_nf_limits *limit;
++	struct ath9k_nfcal_hist *h;
++	bool high_nf_mid = false;
+ 	int i;
+ 
++	h = cal->nfCalHist;
+ 	limit = ath9k_hw_get_nf_limits(ah, ah->curchan);
+ 
+ 	for (i = 0; i < NUM_NF_READINGS; i++) {
+@@ -87,9 +91,38 @@ static void ath9k_hw_update_nfcal_hist_b
+ 				ath9k_hw_get_nf_hist_mid(h[i].nfCalBuffer);
+ 		}
+ 
+-		if (h[i].privNF > limit->max)
+-			h[i].privNF = limit->max;
++		if (!h[i].privNF)
++			continue;
++
++		if (h[i].privNF > limit->max) {
++			high_nf_mid = true;
++
++			ath_print(common, ATH_DBG_CALIBRATE,
++				  "NFmid[%d] (%d) > MAX (%d), %s\n",
++				  i, h[i].privNF, limit->max,
++				  (cal->nfcal_interference ?
++				   "not corrected (due to interference)" :
++				   "correcting to MAX"));
++
++			/*
++			 * Normally we limit the average noise floor by the
++			 * hardware specific maximum here. However if we have
++			 * encountered stuck beacons because of interference,
++			 * we bypass this limit here in order to better deal
++			 * with our environment.
++			 */
++			if (!cal->nfcal_interference)
++				h[i].privNF = limit->max;
++		}
+ 	}
++
++	/*
++	 * If the noise floor seems normal for all chains, assume that
++	 * there is no significant interference in the environment anymore.
++	 * Re-enable the enforcement of the NF maximum again.
++	 */
++	if (!high_nf_mid)
++		cal->nfcal_interference = false;
+ }
+ 
+ static bool ath9k_hw_get_nf_thresh(struct ath_hw *ah,
+@@ -339,7 +372,7 @@ bool ath9k_hw_getnf(struct ath_hw *ah, s
+ 
+ 	h = caldata->nfCalHist;
+ 	caldata->nfcal_pending = false;
+-	ath9k_hw_update_nfcal_hist_buffer(ah, h, nfarray);
++	ath9k_hw_update_nfcal_hist_buffer(ah, caldata, nfarray);
+ 	caldata->rawNoiseFloor = h[0].privNF;
+ 	return true;
+ }
+@@ -374,3 +407,26 @@ s16 ath9k_hw_getchan_noise(struct ath_hw
+ 	return ah->caldata->rawNoiseFloor;
+ }
+ EXPORT_SYMBOL(ath9k_hw_getchan_noise);
++
++void ath9k_hw_bstuck_nfcal(struct ath_hw *ah)
++{
++	struct ath9k_hw_cal_data *caldata = ah->caldata;
++
++	if (unlikely(!caldata))
++		return;
++
++	/*
++	 * If beacons are stuck, the most likely cause is interference.
++	 * Triggering a noise floor calibration at this point helps the
++	 * hardware adapt to a noisy environment much faster.
++	 * To ensure that we recover from stuck beacons quickly, let
++	 * the baseband update the internal NF value itself, similar to
++	 * what is being done after a full reset.
++	 */
++	if (!caldata->nfcal_pending)
++		ath9k_hw_start_nfcal(ah, true);
++
++	caldata->nfcal_interference = true;
++}
++EXPORT_SYMBOL(ath9k_hw_bstuck_nfcal);
++
+--- a/drivers/net/wireless/ath/ath9k/calib.h
++++ b/drivers/net/wireless/ath/ath9k/calib.h
+@@ -113,6 +113,7 @@ void ath9k_hw_loadnf(struct ath_hw *ah, 
+ bool ath9k_hw_getnf(struct ath_hw *ah, struct ath9k_channel *chan);
+ void ath9k_init_nfcal_hist_buffer(struct ath_hw *ah,
+ 				  struct ath9k_channel *chan);
++void ath9k_hw_bstuck_nfcal(struct ath_hw *ah);
+ s16 ath9k_hw_getchan_noise(struct ath_hw *ah, struct ath9k_channel *chan);
+ void ath9k_hw_reset_calibration(struct ath_hw *ah,
+ 				struct ath9k_cal_list *currCal);
+--- a/drivers/net/wireless/ath/ath9k/hw.h
++++ b/drivers/net/wireless/ath/ath9k/hw.h
+@@ -355,6 +355,7 @@ struct ath9k_hw_cal_data {
+ 	int16_t rawNoiseFloor;
+ 	bool paprd_done;
+ 	bool nfcal_pending;
++	bool nfcal_interference;
+ 	u16 small_signal_gain[AR9300_MAX_CHAINS];
+ 	u32 pa_table[AR9300_MAX_CHAINS][PAPRD_TABLE_SZ];
+ 	struct ath9k_nfcal_hist nfCalHist[NUM_NF_READINGS];
diff --git a/package/mac80211/patches/543-ath9k_interference_nf_cal.patch b/package/mac80211/patches/543-ath9k_interference_nf_cal.patch
new file mode 100644
index 000000000..74bee3e14
--- /dev/null
+++ b/package/mac80211/patches/543-ath9k_interference_nf_cal.patch
@@ -0,0 +1,35 @@
+--- a/drivers/net/wireless/ath/ath9k/ath9k.h
++++ b/drivers/net/wireless/ath/ath9k/ath9k.h
+@@ -423,6 +423,7 @@ int ath_beaconq_config(struct ath_softc 
+ #define ATH_AP_SHORT_CALINTERVAL  100     /* 100 ms */
+ #define ATH_ANI_POLLINTERVAL_OLD  100     /* 100 ms */
+ #define ATH_ANI_POLLINTERVAL_NEW  1000    /* 1000 ms */
++#define ATH_LONG_CALINTERVAL_INT  1000    /* 1000 ms */
+ #define ATH_LONG_CALINTERVAL      30000   /* 30 seconds */
+ #define ATH_RESTART_CALINTERVAL   1200000 /* 20 minutes */
+ 
+--- a/drivers/net/wireless/ath/ath9k/main.c
++++ b/drivers/net/wireless/ath/ath9k/main.c
+@@ -396,7 +396,12 @@ void ath_ani_calibrate(unsigned long dat
+ 	bool shortcal = false;
+ 	bool aniflag = false;
+ 	unsigned int timestamp = jiffies_to_msecs(jiffies);
+-	u32 cal_interval, short_cal_interval;
++	u32 cal_interval, short_cal_interval, long_cal_interval;
++
++	if (ah->caldata && ah->caldata->nfcal_interference)
++		long_cal_interval = ATH_LONG_CALINTERVAL_INT;
++	else
++		long_cal_interval = ATH_LONG_CALINTERVAL;
+ 
+ 	short_cal_interval = (ah->opmode == NL80211_IFTYPE_AP) ?
+ 		ATH_AP_SHORT_CALINTERVAL : ATH_STA_SHORT_CALINTERVAL;
+@@ -408,7 +413,7 @@ void ath_ani_calibrate(unsigned long dat
+ 	ath9k_ps_wakeup(sc);
+ 
+ 	/* Long calibration runs independently of short calibration. */
+-	if ((timestamp - common->ani.longcal_timer) >= ATH_LONG_CALINTERVAL) {
++	if ((timestamp - common->ani.longcal_timer) >= long_cal_interval) {
+ 		longcal = true;
+ 		ath_print(common, ATH_DBG_ANI, "longcal @%lu\n", jiffies);
+ 		common->ani.longcal_timer = timestamp;