[PATCH 1/2] ath9k_hw: fix PA predistortion HT40 mask

[PATCH 1/2] ath9k_hw: fix PA predistortion HT40 mask

[Felix Fietkau]

The commit 'ath9k_hw: Disable PAPRD for rates with low Tx power' changed
the code that sets the PAPRD rate masks to use only either the HT20 mask
or the HT40 mask. This is wrong, as the hardware can still use HT20 rates
even when configured for HT40, and the operating channel mode does not
affect PAPRD operation.
The register for the HT40 rate mask is applied as a mask on top of the
other registers to selectively disable PAPRD for specific rates on HT40
packets only.
This patch changes the code back to the old behavior which matches the
intended use of these registers. While with current cards this should not
make any practical difference (according to Atheros, the HT20 and HT40
mask should always be equal), it is more correct that way, and maybe
the HT40 mask will be used for some rare corner cases in the future.

Cc: Vasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
---
 drivers/net/wireless/ath/ath9k/ar9003_eeprom.c |   19 +++++++++++--------
 drivers/net/wireless/ath/ath9k/ar9003_paprd.c  |    2 +-
 drivers/net/wireless/ath/ath9k/hw.h            |    1 +
 3 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c b/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c
index f80ec74..d7deae8 100644
--- a/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c
+++ b/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c
@@ -4762,6 +4762,7 @@ static void ath9k_hw_ar9300_set_txpower(struct ath_hw *ah,
 	struct ath_regulatory *regulatory = ath9k_hw_regulatory(ah);
 	struct ath_common *common = ath9k_hw_common(ah);
 	struct ar9300_eeprom *eep = &ah->eeprom.ar9300_eep;
+	struct ar9300_modal_eep_header *modal_hdr;
 	u8 targetPowerValT2[ar9300RateSize];
 	u8 target_power_val_t2_eep[ar9300RateSize];
 	unsigned int i = 0, paprd_scale_factor = 0;
@@ -4771,15 +4772,17 @@ static void ath9k_hw_ar9300_set_txpower(struct ath_hw *ah,
 
 	if (ah->eep_ops->get_eeprom(ah, EEP_PAPRD)) {
 		if (IS_CHAN_2GHZ(chan))
-			ah->paprd_ratemask = (IS_CHAN_HT40(chan) ?
-				le32_to_cpu(eep->modalHeader2G.papdRateMaskHt40) :
-				le32_to_cpu(eep->modalHeader2G.papdRateMaskHt20))
-				& AR9300_PAPRD_RATE_MASK;
+			modal_hdr = &eep->modalHeader2G;
 		else
-			ah->paprd_ratemask = (IS_CHAN_HT40(chan) ?
-				le32_to_cpu(eep->modalHeader5G.papdRateMaskHt40) :
-				le32_to_cpu(eep->modalHeader5G.papdRateMaskHt20))
-				& AR9300_PAPRD_RATE_MASK;
+			modal_hdr = &eep->modalHeader5G;
+
+		ah->paprd_ratemask =
+			le32_to_cpu(modal_hdr->papdRateMaskHt20) &
+			AR9300_PAPRD_RATE_MASK;
+
+		ah->paprd_ratemask_ht40 =
+			le32_to_cpu(modal_hdr->papdRateMaskHt40) &
+			AR9300_PAPRD_RATE_MASK;
 
 		paprd_scale_factor = ar9003_get_paprd_scale_factor(ah, chan);
 		min_pwridx = IS_CHAN_HT40(chan) ? ALL_TARGET_HT40_0_8_16 :
diff --git a/drivers/net/wireless/ath/ath9k/ar9003_paprd.c b/drivers/net/wireless/ath/ath9k/ar9003_paprd.c
index 79554c5..356d2fd7 100644
--- a/drivers/net/wireless/ath/ath9k/ar9003_paprd.c
+++ b/drivers/net/wireless/ath/ath9k/ar9003_paprd.c
@@ -134,7 +134,7 @@ static int ar9003_paprd_setup_single_table(struct ath_hw *ah)
 	REG_RMW_FIELD(ah, AR_PHY_PAPRD_AM2PM, AR_PHY_PAPRD_AM2PM_MASK,
 		      ah->paprd_ratemask);
 	REG_RMW_FIELD(ah, AR_PHY_PAPRD_HT40, AR_PHY_PAPRD_HT40_MASK,
-		      AR_PHY_PAPRD_HT40_MASK);
+		      ah->paprd_ratemask_ht40);
 
 	for (i = 0; i < ah->caps.max_txchains; i++) {
 		REG_RMW_FIELD(ah, ctrl0[i],
diff --git a/drivers/net/wireless/ath/ath9k/hw.h b/drivers/net/wireless/ath/ath9k/hw.h
index b98053f..b8ffaa5 100644
--- a/drivers/net/wireless/ath/ath9k/hw.h
+++ b/drivers/net/wireless/ath/ath9k/hw.h
@@ -835,6 +835,7 @@ struct ath_hw {
 	unsigned int paprd_target_power;
 	unsigned int paprd_training_power;
 	unsigned int paprd_ratemask;
+	unsigned int paprd_ratemask_ht40;
 	bool paprd_table_write_done;
 	u32 paprd_gain_table_entries[PAPRD_GAIN_TABLE_ENTRIES];
 	u8 paprd_gain_table_index[PAPRD_GAIN_TABLE_ENTRIES];
-- 
1.7.3.2

[PATCH 2/2] ath9k: do not limit the chainmask to 1 for legacy mode

[Felix Fietkau]

Restricting the chainmask to 1 for legacy mode disables useful features
such as MRC, and it reduces the available transmit power.
I can't think of a good reason to do this in legacy mode, so let's just
get rid of that code.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
---
 drivers/net/wireless/ath/ath9k/ath9k.h   |    1 -
 drivers/net/wireless/ath/ath9k/main.c    |   32 ------------------------------
 drivers/net/wireless/ath/ath9k/virtual.c |    1 -
 3 files changed, 0 insertions(+), 34 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index 9fd9519..2c31f51 100644
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -675,7 +675,6 @@ void ath9k_deinit_device(struct ath_softc *sc);
 void ath9k_set_hw_capab(struct ath_softc *sc, struct ieee80211_hw *hw);
 void ath9k_update_ichannel(struct ath_softc *sc, struct ieee80211_hw *hw,
 			   struct ath9k_channel *ichan);
-void ath_update_chainmask(struct ath_softc *sc, int is_ht);
 int ath_set_channel(struct ath_softc *sc, struct ieee80211_hw *hw,
 		    struct ath9k_channel *hchan);
 
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index cb53fbb..8a1691d 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -538,32 +538,6 @@ set_timer:
 	}
 }
 
-/*
- * Update tx/rx chainmask. For legacy association,
- * hard code chainmask to 1x1, for 11n association, use
- * the chainmask configuration, for bt coexistence, use
- * the chainmask configuration even in legacy mode.
- */
-void ath_update_chainmask(struct ath_softc *sc, int is_ht)
-{
-	struct ath_hw *ah = sc->sc_ah;
-	struct ath_common *common = ath9k_hw_common(ah);
-
-	if ((sc->sc_flags & SC_OP_OFFCHANNEL) || is_ht ||
-	    (ah->btcoex_hw.scheme != ATH_BTCOEX_CFG_NONE)) {
-		common->tx_chainmask = ah->caps.tx_chainmask;
-		common->rx_chainmask = ah->caps.rx_chainmask;
-	} else {
-		common->tx_chainmask = 1;
-		common->rx_chainmask = 1;
-	}
-
-	ath_dbg(common, ATH_DBG_CONFIG,
-		"tx chmask: %d, rx chmask: %d\n",
-		common->tx_chainmask,
-		common->rx_chainmask);
-}
-
 static void ath_node_attach(struct ath_softc *sc, struct ieee80211_sta *sta)
 {
 	struct ath_node *an;
@@ -1679,8 +1653,6 @@ static int ath9k_config(struct ieee80211_hw *hw, u32 changed)
 		/* XXX: remove me eventualy */
 		ath9k_update_ichannel(sc, hw, &sc->sc_ah->channels[pos]);
 
-		ath_update_chainmask(sc, conf_is_ht(conf));
-
 		/* update survey stats for the old channel before switching */
 		spin_lock_irqsave(&common->cc_lock, flags);
 		ath_update_survey_stats(sc);
@@ -1912,10 +1884,6 @@ static void ath9k_bss_info_changed(struct ieee80211_hw *hw,
 		/* Set aggregation protection mode parameters */
 		sc->config.ath_aggr_prot = 0;
 
-		/* Only legacy IBSS for now */
-		if (vif->type == NL80211_IFTYPE_ADHOC)
-			ath_update_chainmask(sc, 0);
-
 		ath_dbg(common, ATH_DBG_CONFIG, "BSSID: %pM aid: 0x%x\n",
 			common->curbssid, common->curaid);
 
diff --git a/drivers/net/wireless/ath/ath9k/virtual.c b/drivers/net/wireless/ath/ath9k/virtual.c
index fbfbc82..2dc7095 100644
--- a/drivers/net/wireless/ath/ath9k/virtual.c
+++ b/drivers/net/wireless/ath/ath9k/virtual.c
@@ -288,7 +288,6 @@ void ath9k_wiphy_chan_work(struct work_struct *work)
 	/* sync hw configuration for hw code */
 	common->hw = aphy->hw;
 
-	ath_update_chainmask(sc, sc->chan_is_ht);
 	if (ath_set_channel(sc, aphy->hw,
 			    &sc->sc_ah->channels[sc->chan_idx]) < 0) {
 		printk(KERN_DEBUG "ath9k: Failed to set channel for new "
-- 
1.7.3.2