ath9k_hw: Disable PAPRD for rates with low Tx power

When the drop in Tx power for a particular mcs rate exceeds
the paprd scale factor, paprd may not work properly. Disable
paprd for any such rates.

Signed-off-by: Vasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 45 insertions, 15 deletions

diff --git a/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c b/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c
index 9fa5793abd27..0e9ea35f2fb4 100644
--- a/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c
+++ b/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c
@@ -4751,16 +4751,53 @@ 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;
         u8 targetPowerValT2[ar9300RateSize];
-        unsigned int i = 0;
+        u8 target_power_val_t2_eep[ar9300RateSize];
+        unsigned int i = 0, paprd_scale_factor = 0;
+        u8 pwr_idx, min_pwridx;
 
         ar9003_hw_set_target_power_eeprom(ah, chan->channel, targetPowerValT2);
+
+        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;
+                else
+                        ah->paprd_ratemask = (IS_CHAN_HT40(chan) ?
+                                le32_to_cpu(eep->modalHeader5G.papdRateMaskHt40) :
+                                le32_to_cpu(eep->modalHeader5G.papdRateMaskHt20))
+                                & AR9300_PAPRD_RATE_MASK;
+
+                memcpy(target_power_val_t2_eep, targetPowerValT2,
+                       sizeof(targetPowerValT2));
+        }
+
         ar9003_hw_set_power_per_rate_table(ah, chan,
                                            targetPowerValT2, cfgCtl,
                                            twiceAntennaReduction,
                                            twiceMaxRegulatoryPower,
                                            powerLimit);
 
+        if (ah->eep_ops->get_eeprom(ah, EEP_PAPRD)) {
+                paprd_scale_factor = ar9003_get_paprd_scale_factor(ah, chan);
+                min_pwridx = IS_CHAN_HT40(chan) ? ALL_TARGET_HT40_0_8_16 :
+                                                  ALL_TARGET_HT20_0_8_16;
+
+                for (i = 0; i < ar9300RateSize; i++) {
+                        if ((ah->paprd_ratemask & (1 << i)) &&
+                            (abs(targetPowerValT2[i] -
+                                target_power_val_t2_eep[i]) >
+                            paprd_scale_factor)) {
+                                ah->paprd_ratemask &= ~(1 << i);
+                                ath_dbg(common, ATH_DBG_EEPROM,
+                                        "paprd disabled for mcs %d\n", i);
+                        }
+                }
+        }
+
         regulatory->max_power_level = 0;
         for (i = 0; i < ar9300RateSize; i++) {
                 if (targetPowerValT2[i] > regulatory->max_power_level)
diff --git a/drivers/net/wireless/ath/ath9k/ar9003_paprd.c b/drivers/net/wireless/ath/ath9k/ar9003_paprd.c
index 4c744793b4b6..26cf31cca3ac 100644
--- a/drivers/net/wireless/ath/ath9k/ar9003_paprd.c
+++ b/drivers/net/wireless/ath/ath9k/ar9003_paprd.c
@@ -87,8 +87,6 @@ static int ar9003_get_training_power_5g(struct ath_hw *ah)
 static int ar9003_paprd_setup_single_table(struct ath_hw *ah)
 {
         struct ath_common *common = ath9k_hw_common(ah);
-        struct ar9300_eeprom *eep = &ah->eeprom.ar9300_eep;
-        struct ar9300_modal_eep_header *hdr;
         static const u32 ctrl0[3] = {
                 AR_PHY_PAPRD_CTRL0_B0,
                 AR_PHY_PAPRD_CTRL0_B1,
@@ -99,18 +97,9 @@ static int ar9003_paprd_setup_single_table(struct ath_hw *ah)
                 AR_PHY_PAPRD_CTRL1_B1,
                 AR_PHY_PAPRD_CTRL1_B2
         };
-        u32 am_mask, ht40_mask;
         int training_power;
         int i;
 
-        if (ah->curchan && IS_CHAN_5GHZ(ah->curchan))
-                hdr = &eep->modalHeader5G;
-        else
-                hdr = &eep->modalHeader2G;
-
-        am_mask = le32_to_cpu(hdr->papdRateMaskHt20) & AR9300_PAPRD_RATE_MASK;
-        ht40_mask = le32_to_cpu(hdr->papdRateMaskHt40) & AR9300_PAPRD_RATE_MASK;
-
         if (IS_CHAN_2GHZ(ah->curchan))
                 training_power = ar9003_get_training_power_2g(ah);
         else
@@ -126,9 +115,12 @@ static int ar9003_paprd_setup_single_table(struct ath_hw *ah)
                 "Training power: %d, Target power: %d\n",
                 ah->paprd_training_power, ah->paprd_target_power);
 
-        REG_RMW_FIELD(ah, AR_PHY_PAPRD_AM2AM, AR_PHY_PAPRD_AM2AM_MASK, am_mask);
-        REG_RMW_FIELD(ah, AR_PHY_PAPRD_AM2PM, AR_PHY_PAPRD_AM2PM_MASK, am_mask);
-        REG_RMW_FIELD(ah, AR_PHY_PAPRD_HT40, AR_PHY_PAPRD_HT40_MASK, ht40_mask);
+        REG_RMW_FIELD(ah, AR_PHY_PAPRD_AM2AM, AR_PHY_PAPRD_AM2AM_MASK,
+                      ah->paprd_ratemask);
+        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);
 
         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 fb64ab841dc1..3a6101ba9837 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;
         u32 paprd_gain_table_entries[PAPRD_GAIN_TABLE_ENTRIES];
         u8 paprd_gain_table_index[PAPRD_GAIN_TABLE_ENTRIES];
         /*