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take into account external PA when configuring tx power

PATCH In review Lorenzo Bianconi 3 participants 5 messages Jun 11, 2019

Subsystems (2)
Arm MediaTek MediaTek MT76 wireless LAN driver
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Lorenzo Bianconi

author maintainer
#0 lore raw

cover take into account external PA when configuring tx power

Refer to proper eeprom fields configuring tx power when TSSI calibration is disabled. Moreover initialize per-channel tx power

Lorenzo Bianconi (2):
mt76: mt7615: init per-channel target power
mt76: mt7615: take into account extPA when configuring tx power

 .../wireless/mediatek/mt76/mt7615/eeprom.c    | 12 ++++-
 .../wireless/mediatek/mt76/mt7615/eeprom.h    | 17 +++++++
 .../net/wireless/mediatek/mt76/mt7615/init.c  | 46 +++++++++++++++++++
 .../net/wireless/mediatek/mt76/mt7615/mcu.c   | 10 ++--
 .../wireless/mediatek/mt76/mt7615/mt7615.h    |  3 +-
 5 files changed, 82 insertions(+), 6 deletions(-)
Signature · 1 line
2.21.0
author maintainer
#1 lore raw

PATCH 1/2 mt76: mt7615: init per-channel target power

Set per-channel target power as the minimum between the regulatory tx power and the value configured in the eeprom

Signed-off-by Lorenzo Bianconi <[email protected]>
---
 .../net/wireless/mediatek/mt76/mt7615/init.c  | 43 +++++++++++++++++++
 1 file changed, 43 insertions(+)
drivers/net/wireless/mediatek/mt76/mt7615/init.c +43 -0
index 693e597a3230..3f826e4f1cd6 100644
@@ -165,6 +165,46 @@ static int mt7615_init_debugfs(struct mt7615_dev *dev)
 	return 0;
 }
 
+static void
+mt7615_init_txpower(struct mt7615_dev *dev,
+		    struct ieee80211_supported_band *sband)
+{
+	int i, n_chains = hweight8(dev->mt76.antenna_mask);
+	u8 *eep = (u8 *)dev->mt76.eeprom.data;
+
+	for (i = 0; i < sband->n_channels; i++) {
+		struct ieee80211_channel *chan = &sband->channels[i];
+		u8 target_power = 0;
+		int j;
+
+		for (j = 0; j < n_chains; j++) {
+			int index;
+
+			index = mt7615_eeprom_get_power_index(chan, j);
+			target_power = max(target_power, eep[index]);
+		}
+
+		target_power = DIV_ROUND_UP(target_power, 2);
+		switch (n_chains) {
+		case 4:
+			target_power += 6;
+			break;
+		case 3:
+			target_power += 4;
+			break;
+		case 2:
+			target_power += 3;
+			break;
+		default:
+			break;
+		}
+
+		chan->max_power = min_t(int, chan->max_reg_power,
+					target_power);
+		chan->orig_mpwr = target_power;
+	}
+}
+
 int mt7615_register_device(struct mt7615_dev *dev)
 {
 	struct ieee80211_hw *hw = mt76_hw(dev);

@@ -212,6 +252,9 @@ int mt7615_register_device(struct mt7615_dev *dev)
 	if (ret)
 		return ret;
 
+	mt7615_init_txpower(dev, &dev->mt76.sband_2g.sband);
+	mt7615_init_txpower(dev, &dev->mt76.sband_5g.sband);
+
 	hw->max_tx_fragments = MT_TXP_MAX_BUF_NUM;
 
 	return mt7615_init_debugfs(dev);
Signature · 1 line
2.21.0
#2 lore raw

Re: [PATCH 1/2] mt76: mt7615: init per-channel target power

drivers/net/wireless/mediatek/mt76/mt7615/init.c static int mt7615_init_debugfs(struct mt7615_dev *dev) · line 200

Quoted 13 lines · On Tuesday, 11 June 2019 08:38:52 CEST Lorenzo Bianconi wrote:
drivers/net/wireless/mediatek/mt76/mt7615/init.c +13 -0
+               switch (n_chains) {
+               case 4:
+                       target_power += 6;
+                       break;
+               case 3:
+                       target_power += 4;
+                       break;
+               case 2:
+                       target_power += 3;
+                       break;
+               default:
+                       break;
+               }

Any reason why you use different value for 3 chains than ath9k? Following values are used in ath9k:

* 1 chain: 0 dB
* 2 chains: 3 dB (max combined gain ~3.010299956639812 dB)
* 3 chains: 5 dB (max combined gain ~4.771212547196624 dB)
* 4 chains: not supported (max combined gain 6.020599913279624 dB)

Here are the definitions from ath9k (values are saved in .5 dB steps)

    drivers/net/wireless/ath/ath9k/eeprom.h:#define POWER_CORRECTION_FOR_TWO_CHAIN          6  /* 10*log10(2)*2 */
    drivers/net/wireless/ath/ath9k/eeprom.h:#define POWER_CORRECTION_FOR_THREE_CHAIN        10 /* 10*log10(3)*2 */

Kind regards,
Sven

#3 lore raw

Re: [PATCH 1/2] mt76: mt7615: init per-channel target power

Quoted 15 lines · On Tuesday, 11 June 2019 08:38:52 CEST Lorenzo Bianconi wrote:

drivers/net/wireless/mediatek/mt76/mt7615/init.c static int mt7615_init_debugfs(struct mt7615_dev *dev) · line 200

Quoted 13 lines
drivers/net/wireless/mediatek/mt76/mt7615/init.c +13 -0
+               switch (n_chains) {
+               case 4:
+                       target_power += 6;
+                       break;
+               case 3:
+                       target_power += 4;
+                       break;
+               case 2:
+                       target_power += 3;
+                       break;
+               default:
+                       break;
+               }
Quoted 6 lines

Any reason why you use different value for 3 chains than ath9k? Following values are used in ath9k:

* 1 chain: 0 dB
* 2 chains: 3 dB (max combined gain ~3.010299956639812 dB)
* 3 chains: 5 dB (max combined gain ~4.771212547196624 dB)

Hi Sven,

I just rounded down the values, but we can use 5db (in this case we need to fix it even in mt76_get_power(), so I will do it in a different patch)

Regards,
Lorenzo

Quoted 9 lines

* 4 chains: not supported (max combined gain 6.020599913279624 dB)

Here are the definitions from ath9k (values are saved in .5 dB steps)

    drivers/net/wireless/ath/ath9k/eeprom.h:#define POWER_CORRECTION_FOR_TWO_CHAIN          6  /* 10*log10(2)*2 */
    drivers/net/wireless/ath/ath9k/eeprom.h:#define POWER_CORRECTION_FOR_THREE_CHAIN        10 /* 10*log10(3)*2 */

Kind regards,
Sven

author maintainer
#4 lore raw

PATCH 2/2 mt76: mt7615: take into account extPA when configuring tx power

In reply to Lorenzo Bianconi

When TSSI calibration is disabled (which it means the device has been equipped with an external power amplifier) we need to refer to different eeprom fields in order to properly configure tx power

Signed-off-by Lorenzo Bianconi <[email protected]>

---
please note I have not been able to test this patch since I have no devices with external PA

---
 .../net/wireless/mediatek/mt76/mt7615/eeprom.c  | 12 +++++++++++-
 .../net/wireless/mediatek/mt76/mt7615/eeprom.h  | 17 +++++++++++++++++
 .../net/wireless/mediatek/mt76/mt7615/init.c    |  9 ++++++---
 drivers/net/wireless/mediatek/mt76/mt7615/mcu.c | 10 ++++++----
 .../net/wireless/mediatek/mt76/mt7615/mt7615.h  |  3 ++-
 5 files changed, 42 insertions(+), 9 deletions(-)
drivers/net/wireless/mediatek/mt76/mt7615/eeprom.c +11 -1
index 023c8bbc767d..dc94f52e6e8b 100644
@@ -110,7 +110,8 @@ static void mt7615_eeprom_parse_hw_cap(struct mt7615_dev *dev)
 	}
 }
 
-int mt7615_eeprom_get_power_index(struct ieee80211_channel *chan,
+int mt7615_eeprom_get_power_index(struct mt7615_dev *dev,
+				  struct ieee80211_channel *chan,
 				  u8 chain_idx)
 {
 	int index;

@@ -118,6 +119,15 @@ int mt7615_eeprom_get_power_index(struct ieee80211_channel *chan,
 	if (chain_idx > 3)
 		return -EINVAL;
 
+	/* TSSI disabled */
+	if (mt7615_ext_pa_enabled(dev, chan->band)) {
+		if (chan->band == NL80211_BAND_2GHZ)
+			return MT_EE_EXT_PA_2G_TARGET_POWER;
+		else
+			return MT_EE_EXT_PA_5G_TARGET_POWER;
+	}
+
+	/* TSSI enabled */
 	if (chan->band == NL80211_BAND_2GHZ) {
 		index = MT_EE_TX0_2G_TARGET_POWER + chain_idx * 6;
 	} else {
drivers/net/wireless/mediatek/mt76/mt7615/eeprom.h +17 -0
index 3c9086b67f51..f4a4280768d2 100644
@@ -11,16 +11,22 @@ enum mt7615_eeprom_field {
 	MT_EE_VERSION =				0x002,
 	MT_EE_MAC_ADDR =			0x004,
 	MT_EE_NIC_CONF_0 =			0x034,
+	MT_EE_NIC_CONF_1 =			0x036,
 	MT_EE_WIFI_CONF =			0x03e,
 	MT_EE_TX0_2G_TARGET_POWER =		0x058,
 	MT_EE_TX0_5G_G0_TARGET_POWER =		0x070,
 	MT_EE_TX1_5G_G0_TARGET_POWER =		0x098,
+	MT_EE_EXT_PA_2G_TARGET_POWER =		0x0f2,
+	MT_EE_EXT_PA_5G_TARGET_POWER =		0x0f3,
 	MT_EE_TX2_5G_G0_TARGET_POWER =		0x142,
 	MT_EE_TX3_5G_G0_TARGET_POWER =		0x16a,
 
 	__MT_EE_MAX =				0x3bf
 };
 
+#define MT_EE_NIC_CONF_TSSI_2G			BIT(5)
+#define MT_EE_NIC_CONF_TSSI_5G			BIT(6)
+
 #define MT_EE_NIC_WIFI_CONF_BAND_SEL		GENMASK(5, 4)
 enum mt7615_eeprom_band {
 	MT_EE_DUAL_BAND,

@@ -59,4 +65,15 @@ mt7615_get_channel_group(int channel)
 	return MT_CH_5G_UNII_3;
 }
 
+static inline bool
+mt7615_ext_pa_enabled(struct mt7615_dev *dev, enum nl80211_band band)
+{
+	u8 *eep = dev->mt76.eeprom.data;
+
+	if (band == NL80211_BAND_5GHZ)
+		return !(eep[MT_EE_NIC_CONF_1 + 1] & MT_EE_NIC_CONF_TSSI_5G);
+	else
+		return !(eep[MT_EE_NIC_CONF_1 + 1] & MT_EE_NIC_CONF_TSSI_2G);
+}
+
 #endif
drivers/net/wireless/mediatek/mt76/mt7615/init.c +6 -3
index 3f826e4f1cd6..859de2454ec6 100644
@@ -9,6 +9,7 @@
 #include <linux/etherdevice.h>
 #include "mt7615.h"
 #include "mac.h"
+#include "eeprom.h"
 
 static void mt7615_phy_init(struct mt7615_dev *dev)
 {

@@ -169,18 +170,20 @@ static void
 mt7615_init_txpower(struct mt7615_dev *dev,
 		    struct ieee80211_supported_band *sband)
 {
-	int i, n_chains = hweight8(dev->mt76.antenna_mask);
+	int i, n_chains = hweight8(dev->mt76.antenna_mask), target_chains;
 	u8 *eep = (u8 *)dev->mt76.eeprom.data;
+	enum nl80211_band band = sband->band;
 
+	target_chains = mt7615_ext_pa_enabled(dev, band) ? 1 : n_chains;
 	for (i = 0; i < sband->n_channels; i++) {
 		struct ieee80211_channel *chan = &sband->channels[i];
 		u8 target_power = 0;
 		int j;
 
-		for (j = 0; j < n_chains; j++) {
+		for (j = 0; j < target_chains; j++) {
 			int index;
 
-			index = mt7615_eeprom_get_power_index(chan, j);
+			index = mt7615_eeprom_get_power_index(dev, chan, j);
 			target_power = max(target_power, eep[index]);
 		}
drivers/net/wireless/mediatek/mt76/mt7615/mcu.c +6 -4
index 79baa455034c..f3dd76f88ff1 100644
@@ -1149,9 +1149,10 @@ int mt7615_mcu_set_tx_power(struct mt7615_dev *dev)
 {
 	int i, ret, n_chains = hweight8(dev->mt76.antenna_mask);
 	struct cfg80211_chan_def *chandef = &dev->mt76.chandef;
+	int freq = chandef->center_freq1, len, target_chains;
 	u8 *req, *data, *eep = (u8 *)dev->mt76.eeprom.data;
+	enum nl80211_band band = chandef->chan->band;
 	struct ieee80211_hw *hw = mt76_hw(dev);
-	int freq = chandef->center_freq1, len;
 	struct {
 		u8 center_chan;
 		u8 dbdc_idx;

@@ -1159,7 +1160,7 @@ int mt7615_mcu_set_tx_power(struct mt7615_dev *dev)
 		u8 rsv;
 	} __packed req_hdr = {
 		.center_chan = ieee80211_frequency_to_channel(freq),
-		.band = chandef->chan->band,
+		.band = band,
 	};
 	s8 tx_power;
 

@@ -1190,10 +1191,11 @@ int mt7615_mcu_set_tx_power(struct mt7615_dev *dev)
 	tx_power = max_t(s8, tx_power, 0);
 	dev->mt76.txpower_cur = tx_power;
 
-	for (i = 0; i < n_chains; i++) {
+	target_chains = mt7615_ext_pa_enabled(dev, band) ? 1 : n_chains;
+	for (i = 0; i < target_chains; i++) {
 		int index = -MT_EE_NIC_CONF_0;
 
-		ret = mt7615_eeprom_get_power_index(chandef->chan, i);
+		ret = mt7615_eeprom_get_power_index(dev, chandef->chan, i);
 		if (ret < 0)
 			goto out;
drivers/net/wireless/mediatek/mt76/mt7615/mt7615.h +2 -1
index 7c08d3b93a2a..f02ffcffe637 100644
@@ -105,7 +105,8 @@ u32 mt7615_reg_map(struct mt7615_dev *dev, u32 addr);
 int mt7615_register_device(struct mt7615_dev *dev);
 void mt7615_unregister_device(struct mt7615_dev *dev);
 int mt7615_eeprom_init(struct mt7615_dev *dev);
-int mt7615_eeprom_get_power_index(struct ieee80211_channel *chan,
+int mt7615_eeprom_get_power_index(struct mt7615_dev *dev,
+				  struct ieee80211_channel *chan,
 				  u8 chain_idx);
 int mt7615_dma_init(struct mt7615_dev *dev);
 void mt7615_dma_cleanup(struct mt7615_dev *dev);
Signature · 1 line
2.21.0