+commit 1abdeca3c6fb9cf1f84f85e78ed8d1c33bd69db0
+Author: Felix Fietkau <nbd@openwrt.org>
+Date: Fri Feb 28 18:52:56 2014 +0100
+
+ ath9k_hw: tweak noise immunity thresholds for older chipsets
+
+ Older chipsets are more sensitive to high PHY error counts, and the
+ current noise immunity thresholds were based on tests run at QCA with
+ newer chipsets.
+
+ This patch brings back the values from the old ANI implementation for
+ old chipsets, and it also disables weak signal detection on an earlier
+ noise immunity level, to improve overall radio stability on affected
+ devices.
+
+ Signed-off-by: Felix Fietkau <nbd@openwrt.org>
+
+commit 431e506da5953adc3b65af25f4b90873d528c115
+Author: Felix Fietkau <nbd@openwrt.org>
+Date: Fri Feb 28 18:44:13 2014 +0100
+
+ ath9k_hw: toggle weak signal detection in AP mode on older chipsets
+
+ The commit 80b4205b "ath9k: Fix OFDM weak signal detection for AP mode"
+ prevented weak signal detection changes from taking effect in AP mode on
+ all chipsets, claiming it is "not allowed".
+
+ The main reason for not disabling weak signal detection in AP mode is
+ that typically beacon RSSI is used to track whether it is needed to
+ boost range, and this is unavailable in AP mode for obvious reasons.
+
+ The problem with not disabling weak signal detection is that older
+ chipsets are very sensitive to high PHY error counts. When faced with
+ heavy noise, this can lead to an excessive amount of "Failed to stop
+ TX DMA" errors in the field.
+
+ Signed-off-by: Felix Fietkau <nbd@openwrt.org>
+
+commit 98d1a6c5b14688ed030e81b889f607be308e0df9
+Author: Felix Fietkau <nbd@openwrt.org>
+Date: Mon Feb 24 22:20:32 2014 +0100
+
+ ath9k: fix invalid descriptor discarding
+
+ Only set sc->rx.discard_next to rx_stats->rs_more when actually
+ discarding the current descriptor.
+
+ Also, fix a detection of broken descriptors:
+ First the code checks if the current descriptor is not done.
+ Then it checks if the next descriptor is done.
+ Add a check that afterwards checks the first descriptor again, because
+ it might have been completed in the mean time.
+
+ This fixes a regression introduced in
+ commit 723e711356b5a8a95728a890e254e8b0d47b55cf
+ "ath9k: fix handling of broken descriptors"
+
+ Cc: stable@vger.kernel.org
+ Reported-by: Marco André Dinis <marcoandredinis@gmail.com>
+ Signed-off-by: Felix Fietkau <nbd@openwrt.org>
+
+commit 52a46300e782fe6994466523eb2b0b59091ea59f
+Author: Felix Fietkau <nbd@openwrt.org>
+Date: Mon Feb 24 11:43:50 2014 +0100
+
+ ath9k: reduce baseband hang detection false positive rate
+
+ Check if the baseband state remains stable, and add a small delay
+ between register reads.
+
+ Signed-off-by: Felix Fietkau <nbd@openwrt.org>
+
commit 118945bb12082e9d4edddc868d88143164e0f440
Author: Felix Fietkau <nbd@openwrt.org>
Date: Sat Feb 22 14:55:23 2014 +0100
else
udelay(100);
-@@ -2051,9 +2051,8 @@ static bool ath9k_hw_set_power_awake(str
+@@ -1534,7 +1534,7 @@ EXPORT_SYMBOL(ath9k_hw_check_nav);
+ bool ath9k_hw_check_alive(struct ath_hw *ah)
+ {
+ int count = 50;
+- u32 reg;
++ u32 reg, last_val;
+
+ if (AR_SREV_9300(ah))
+ return !ath9k_hw_detect_mac_hang(ah);
+@@ -1542,9 +1542,13 @@ bool ath9k_hw_check_alive(struct ath_hw
+ if (AR_SREV_9285_12_OR_LATER(ah))
+ return true;
+
++ last_val = REG_READ(ah, AR_OBS_BUS_1);
+ do {
+ reg = REG_READ(ah, AR_OBS_BUS_1);
++ if (reg != last_val)
++ return true;
+
++ last_val = reg;
+ if ((reg & 0x7E7FFFEF) == 0x00702400)
+ continue;
+
+@@ -1556,6 +1560,8 @@ bool ath9k_hw_check_alive(struct ath_hw
+ default:
+ return true;
+ }
++
++ udelay(1);
+ } while (count-- > 0);
+
+ return false;
+@@ -2051,9 +2057,8 @@ static bool ath9k_hw_set_power_awake(str
REG_SET_BIT(ah, AR_RTC_FORCE_WAKE,
AR_RTC_FORCE_WAKE_EN);
SURVEY_INFO_CHANNEL_TIME |
SURVEY_INFO_CHANNEL_TIME_BUSY |
SURVEY_INFO_CHANNEL_TIME_RX |
+--- a/drivers/net/wireless/ath/ath9k/recv.c
++++ b/drivers/net/wireless/ath/ath9k/recv.c
+@@ -732,11 +732,18 @@ static struct ath_rxbuf *ath_get_next_rx
+ return NULL;
+
+ /*
+- * mark descriptor as zero-length and set the 'more'
+- * flag to ensure that both buffers get discarded
++ * Re-check previous descriptor, in case it has been filled
++ * in the mean time.
+ */
+- rs->rs_datalen = 0;
+- rs->rs_more = true;
++ ret = ath9k_hw_rxprocdesc(ah, ds, rs);
++ if (ret == -EINPROGRESS) {
++ /*
++ * mark descriptor as zero-length and set the 'more'
++ * flag to ensure that both buffers get discarded
++ */
++ rs->rs_datalen = 0;
++ rs->rs_more = true;
++ }
+ }
+
+ list_del(&bf->list);
+@@ -985,32 +992,32 @@ static int ath9k_rx_skb_preprocess(struc
+ struct ath_common *common = ath9k_hw_common(ah);
+ struct ieee80211_hdr *hdr;
+ bool discard_current = sc->rx.discard_next;
+- int ret = 0;
+
+ /*
+ * Discard corrupt descriptors which are marked in
+ * ath_get_next_rx_buf().
+ */
+- sc->rx.discard_next = rx_stats->rs_more;
+ if (discard_current)
+- return -EINVAL;
++ goto corrupt;
++
++ sc->rx.discard_next = false;
+
+ /*
+ * Discard zero-length packets.
+ */
+ if (!rx_stats->rs_datalen) {
+ RX_STAT_INC(rx_len_err);
+- return -EINVAL;
++ goto corrupt;
+ }
+
+- /*
+- * rs_status follows rs_datalen so if rs_datalen is too large
+- * we can take a hint that hardware corrupted it, so ignore
+- * those frames.
+- */
++ /*
++ * rs_status follows rs_datalen so if rs_datalen is too large
++ * we can take a hint that hardware corrupted it, so ignore
++ * those frames.
++ */
+ if (rx_stats->rs_datalen > (common->rx_bufsize - ah->caps.rx_status_len)) {
+ RX_STAT_INC(rx_len_err);
+- return -EINVAL;
++ goto corrupt;
+ }
+
+ /* Only use status info from the last fragment */
+@@ -1024,10 +1031,8 @@ static int ath9k_rx_skb_preprocess(struc
+ * This is different from the other corrupt descriptor
+ * condition handled above.
+ */
+- if (rx_stats->rs_status & ATH9K_RXERR_CORRUPT_DESC) {
+- ret = -EINVAL;
+- goto exit;
+- }
++ if (rx_stats->rs_status & ATH9K_RXERR_CORRUPT_DESC)
++ goto corrupt;
+
+ hdr = (struct ieee80211_hdr *) (skb->data + ah->caps.rx_status_len);
+
+@@ -1043,18 +1048,15 @@ static int ath9k_rx_skb_preprocess(struc
+ if (ath_process_fft(sc, hdr, rx_stats, rx_status->mactime))
+ RX_STAT_INC(rx_spectral);
+
+- ret = -EINVAL;
+- goto exit;
++ return -EINVAL;
+ }
+
+ /*
+ * everything but the rate is checked here, the rate check is done
+ * separately to avoid doing two lookups for a rate for each frame.
+ */
+- if (!ath9k_rx_accept(common, hdr, rx_status, rx_stats, decrypt_error)) {
+- ret = -EINVAL;
+- goto exit;
+- }
++ if (!ath9k_rx_accept(common, hdr, rx_status, rx_stats, decrypt_error))
++ return -EINVAL;
+
+ if (ath_is_mybeacon(common, hdr)) {
+ RX_STAT_INC(rx_beacons);
+@@ -1064,15 +1066,11 @@ static int ath9k_rx_skb_preprocess(struc
+ /*
+ * This shouldn't happen, but have a safety check anyway.
+ */
+- if (WARN_ON(!ah->curchan)) {
+- ret = -EINVAL;
+- goto exit;
+- }
++ if (WARN_ON(!ah->curchan))
++ return -EINVAL;
+
+- if (ath9k_process_rate(common, hw, rx_stats, rx_status)) {
+- ret =-EINVAL;
+- goto exit;
+- }
++ if (ath9k_process_rate(common, hw, rx_stats, rx_status))
++ return -EINVAL;
+
+ ath9k_process_rssi(common, hw, rx_stats, rx_status);
+
+@@ -1087,9 +1085,11 @@ static int ath9k_rx_skb_preprocess(struc
+ sc->rx.num_pkts++;
+ #endif
+
+-exit:
+- sc->rx.discard_next = false;
+- return ret;
++ return 0;
++
++corrupt:
++ sc->rx.discard_next = rx_stats->rs_more;
++ return -EINVAL;
+ }
+
+ static void ath9k_rx_skb_postprocess(struct ath_common *common,
+--- a/drivers/net/wireless/ath/ath9k/ani.c
++++ b/drivers/net/wireless/ath/ath9k/ani.c
+@@ -176,16 +176,26 @@ static void ath9k_hw_set_ofdm_nil(struct
+ if (ah->opmode == NL80211_IFTYPE_STATION &&
+ BEACON_RSSI(ah) <= ATH9K_ANI_RSSI_THR_HIGH)
+ weak_sig = true;
+-
+ /*
+- * OFDM Weak signal detection is always enabled for AP mode.
++ * Newer chipsets are better at dealing with high PHY error counts -
++ * keep weak signal detection enabled when no RSSI threshold is
++ * available to determine if it is needed (mode != STA)
+ */
+- if (ah->opmode != NL80211_IFTYPE_AP &&
+- aniState->ofdmWeakSigDetect != weak_sig) {
+- ath9k_hw_ani_control(ah,
+- ATH9K_ANI_OFDM_WEAK_SIGNAL_DETECTION,
+- entry_ofdm->ofdm_weak_signal_on);
+- }
++ else if (AR_SREV_9300_20_OR_LATER(ah) &&
++ ah->opmode != NL80211_IFTYPE_STATION)
++ weak_sig = true;
++
++ /* Older chipsets are more sensitive to high PHY error counts */
++ else if (!AR_SREV_9300_20_OR_LATER(ah) &&
++ aniState->ofdmNoiseImmunityLevel >= 8)
++ weak_sig = false;
++
++ if (aniState->ofdmWeakSigDetect != weak_sig)
++ ath9k_hw_ani_control(ah, ATH9K_ANI_OFDM_WEAK_SIGNAL_DETECTION,
++ weak_sig);
++
++ if (!AR_SREV_9300_20_OR_LATER(ah))
++ return;
+
+ if (aniState->ofdmNoiseImmunityLevel >= ATH9K_ANI_OFDM_DEF_LEVEL) {
+ ah->config.ofdm_trig_high = ATH9K_ANI_OFDM_TRIG_HIGH;
+@@ -483,10 +493,17 @@ void ath9k_hw_ani_init(struct ath_hw *ah
+
+ ath_dbg(common, ANI, "Initialize ANI\n");
+
+- ah->config.ofdm_trig_high = ATH9K_ANI_OFDM_TRIG_HIGH;
+- ah->config.ofdm_trig_low = ATH9K_ANI_OFDM_TRIG_LOW;
+- ah->config.cck_trig_high = ATH9K_ANI_CCK_TRIG_HIGH;
+- ah->config.cck_trig_low = ATH9K_ANI_CCK_TRIG_LOW;
++ if (AR_SREV_9300_20_OR_LATER(ah)) {
++ ah->config.ofdm_trig_high = ATH9K_ANI_OFDM_TRIG_HIGH;
++ ah->config.ofdm_trig_low = ATH9K_ANI_OFDM_TRIG_LOW;
++ ah->config.cck_trig_high = ATH9K_ANI_CCK_TRIG_HIGH;
++ ah->config.cck_trig_low = ATH9K_ANI_CCK_TRIG_LOW;
++ } else {
++ ah->config.ofdm_trig_high = ATH9K_ANI_OFDM_TRIG_HIGH_OLD;
++ ah->config.ofdm_trig_low = ATH9K_ANI_OFDM_TRIG_LOW_OLD;
++ ah->config.cck_trig_high = ATH9K_ANI_CCK_TRIG_HIGH_OLD;
++ ah->config.cck_trig_low = ATH9K_ANI_CCK_TRIG_LOW_OLD;
++ }
+
+ ani->spurImmunityLevel = ATH9K_ANI_SPUR_IMMUNE_LVL;
+ ani->firstepLevel = ATH9K_ANI_FIRSTEP_LVL;
+--- a/drivers/net/wireless/ath/ath9k/ani.h
++++ b/drivers/net/wireless/ath/ath9k/ani.h
+@@ -22,12 +22,16 @@
+ /* units are errors per second */
+ #define ATH9K_ANI_OFDM_TRIG_HIGH 3500
+ #define ATH9K_ANI_OFDM_TRIG_HIGH_BELOW_INI 1000
++#define ATH9K_ANI_OFDM_TRIG_HIGH_OLD 500
+
+ #define ATH9K_ANI_OFDM_TRIG_LOW 400
+ #define ATH9K_ANI_OFDM_TRIG_LOW_ABOVE_INI 900
++#define ATH9K_ANI_OFDM_TRIG_LOW_OLD 200
+
+ #define ATH9K_ANI_CCK_TRIG_HIGH 600
++#define ATH9K_ANI_CCK_TRIG_HIGH_OLD 200
+ #define ATH9K_ANI_CCK_TRIG_LOW 300
++#define ATH9K_ANI_CCK_TRIG_LOW_OLD 100
+
+ #define ATH9K_ANI_SPUR_IMMUNE_LVL 3
+ #define ATH9K_ANI_FIRSTEP_LVL 2