Commit c3ae2103 authored by Felix Fietkau's avatar Felix Fietkau Committed by Kalle Valo
Browse files

mt76: improve gain adjustment in noisy environments 



When switching between low gain (high RSSI) and high gain settings, it
can take a few seconds to adjust to the current environment.
This can lead to short periods of time with extreme packet loss.

When switching from low_gain=1 to low_gain=2, start with the same gain
adjustment value instead of the lowest to avoid spikes of huge numbers
of false CCA events

Also avoid resetting adjustment values on switching between low_gain
values 0 and 1, since it affects only the upper limit of vga adjustment

Signed-off-by: default avatarFelix Fietkau <nbd@nbd.name>
Signed-off-by: default avatarKalle Valo <kvalo@codeaurora.org>
parent 32e49efe

drivers/net/wireless/mediatek/mt76/mt76x2_phy.c

+16 −10
Original line number Diff line number Diff line
@@ -491,7 +491,8 @@ mt76x2_phy_adjust_vga_gain(struct mt76x2_dev *dev) 
	dev->cal.false_cca = false_cca;

	if (false_cca > 800 && dev->cal.agc_gain_adjust < limit)

		dev->cal.agc_gain_adjust += 2;

	else if (false_cca < 10 && dev->cal.agc_gain_adjust > 0)

	else if ((false_cca < 10 && dev->cal.agc_gain_adjust > 0) ||

		 (dev->cal.agc_gain_adjust >= limit && false_cca < 500))

		dev->cal.agc_gain_adjust -= 2;

	else

		return;
@@ -550,7 +551,8 @@ static void 
mt76x2_phy_update_channel_gain(struct mt76x2_dev *dev)

{

	u8 *gain = dev->cal.agc_gain_init;

	u8 gain_delta;

	u8 low_gain_delta, gain_delta;

	bool gain_change;

	int low_gain;

	u32 val;
@@ -559,13 +561,14 @@ mt76x2_phy_update_channel_gain(struct mt76x2_dev *dev) 
	low_gain = (dev->cal.avg_rssi_all > mt76x2_get_rssi_gain_thresh(dev)) +

		   (dev->cal.avg_rssi_all > mt76x2_get_low_rssi_gain_thresh(dev));



	if (dev->cal.low_gain == low_gain) {

	gain_change = (dev->cal.low_gain & 2) ^ (low_gain & 2);

	dev->cal.low_gain = low_gain;



	if (!gain_change) {

		mt76x2_phy_adjust_vga_gain(dev);

		return;

	}



	dev->cal.low_gain = low_gain;



	if (dev->mt76.chandef.width == NL80211_CHAN_WIDTH_80) {

		mt76_wr(dev, MT_BBP(RXO, 14), 0x00560211);

		val = mt76_rr(dev, MT_BBP(AGC, 26)) & ~0xf;
@@ -578,14 +581,17 @@ mt76x2_phy_update_channel_gain(struct mt76x2_dev *dev) 
		mt76_wr(dev, MT_BBP(RXO, 14), 0x00560423);

	}



	if (mt76x2_has_ext_lna(dev))

		low_gain_delta = 10;

	else

		low_gain_delta = 14;



	if (low_gain == 2) {

		mt76_wr(dev, MT_BBP(RXO, 18), 0xf000a990);

		mt76_wr(dev, MT_BBP(AGC, 35), 0x08080808);

		mt76_wr(dev, MT_BBP(AGC, 37), 0x08080808);

		if (mt76x2_has_ext_lna(dev))

			gain_delta = 10;

		else

			gain_delta = 14;

		gain_delta = low_gain_delta;

		dev->cal.agc_gain_adjust = 0;

	} else {

		mt76_wr(dev, MT_BBP(RXO, 18), 0xf000a991);

		if (dev->mt76.chandef.width == NL80211_CHAN_WIDTH_80)
@@ -594,11 +600,11 @@ mt76x2_phy_update_channel_gain(struct mt76x2_dev *dev) 
			mt76_wr(dev, MT_BBP(AGC, 35), 0x11111116);

		mt76_wr(dev, MT_BBP(AGC, 37), 0x2121262C);

		gain_delta = 0;

		dev->cal.agc_gain_adjust = low_gain_delta;

	}



	dev->cal.agc_gain_cur[0] = gain[0] - gain_delta;

	dev->cal.agc_gain_cur[1] = gain[1] - gain_delta;

	dev->cal.agc_gain_adjust = 0;

	mt76x2_phy_set_gain_val(dev);



	/* clear false CCA counters */

CRA Git | Maintained and supported by SUSTech CRA and CCSE