[PATCH 5.19 0486/1157] mt76: mt7615: fix throughput regression on DFS channels

Greg Kroah-Hartman
2022-08-15T23:56:38Z

From: Felix Fietkau <nbd@nbd.name>

[ Upstream commit aac86cebb4a09e3fa2c07589f79f7d0e07e8c9a4 ]

For some reason, mt7615 reacts badly to repeatedly enabling/disabling the radar
detector without also switching the channel.
This results in very bad throughput on DFS channels, because
hw->conf.radar_enabled can get toggled a few times after CAC ends.
Fix this by always leaving the DFS detector enabled on DFS channels and instead
suppress unwanted detection events.

Fixes: 2c86f6752046 ("mt76: mt7615: fix/rewrite the dfs state handling logic")
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
.../net/wireless/mediatek/mt76/mt7615/mac.c | 7 ++++---
.../net/wireless/mediatek/mt76/mt7615/main.c | 21 -------------------
.../net/wireless/mediatek/mt76/mt7615/mcu.c | 3 +++
.../wireless/mediatek/mt76/mt7615/mt7615.h | 1 -
4 files changed, 7 insertions(+), 25 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/mac.c b/drivers/net/wireless/mediatek/mt76/mt7615/mac.c
index bd687f7de628..9e832b27170f 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7615/mac.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7615/mac.c
@@ -2282,6 +2282,7 @@ mt7615_dfs_init_radar_specs(struct mt7615_phy *phy)

int mt7615_dfs_init_radar_detector(struct mt7615_phy *phy)
{
+ struct cfg80211_chan_def *chandef = &phy->mt76->chandef;
struct mt7615_dev *dev = phy->dev;
bool ext_phy = phy != &dev->phy;
enum mt76_dfs_state dfs_state, prev_state;
@@ -2292,13 +2293,13 @@ int mt7615_dfs_init_radar_detector(struct mt7615_phy *phy)

prev_state = phy->mt76->dfs_state;
dfs_state = mt76_phy_dfs_state(phy->mt76);
+ if ((chandef->chan->flags & IEEE80211_CHAN_RADAR) &&
+ dfs_state < MT_DFS_STATE_CAC)
+ dfs_state = MT_DFS_STATE_ACTIVE;

if (prev_state == dfs_state)
return 0;

- if (prev_state == MT_DFS_STATE_UNKNOWN)
- mt7615_dfs_stop_radar_detector(phy);
-
if (dfs_state == MT_DFS_STATE_DISABLED)
goto stop;

diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/main.c b/drivers/net/wireless/mediatek/mt76/mt7615/main.c
index a9c9b97d173e..d722c3c177be 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7615/main.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7615/main.c
@@ -282,26 +282,6 @@ static void mt7615_remove_interface(struct ieee80211_hw *hw,
mt76_packet_id_flush(&dev->mt76, &mvif->sta.wcid);
}

-static void mt7615_init_dfs_state(struct mt7615_phy *phy)
-{
- struct mt76_phy *mphy = phy->mt76;
- struct ieee80211_hw *hw = mphy->hw;
- struct cfg80211_chan_def *chandef = &hw->conf.chandef;
-
- if (hw->conf.flags & IEEE80211_CONF_OFFCHANNEL)
- return;
-
- if (!(chandef->chan->flags & IEEE80211_CHAN_RADAR) &&
- !(mphy->chandef.chan->flags & IEEE80211_CHAN_RADAR))
- return;
-
- if (mphy->chandef.chan->center_freq == chandef->chan->center_freq &&
- mphy->chandef.width == chandef->width)
- return;
-
- phy->dfs_state = -1;
-}
-
int mt7615_set_channel(struct mt7615_phy *phy)
{
struct mt7615_dev *dev = phy->dev;
@@ -314,7 +294,6 @@ int mt7615_set_channel(struct mt7615_phy *phy)

set_bit(MT76_RESET, &phy->mt76->state);

- mt7615_init_dfs_state(phy);
mt76_set_channel(phy->mt76);

if (is_mt7615(&dev->mt76) && dev->flash_eeprom) {
diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/mcu.c b/drivers/net/wireless/mediatek/mt76/mt7615/mcu.c
index d2dd1260382c..8a7bc78da954 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7615/mcu.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7615/mcu.c
@@ -403,6 +403,9 @@ mt7615_mcu_rx_radar_detected(struct mt7615_dev *dev, struct sk_buff *skb)
if (r->band_idx && dev->mt76.phy2)
mphy = dev->mt76.phy2;

+ if (mt76_phy_dfs_state(mphy) < MT_DFS_STATE_CAC)
+ return;
+
ieee80211_radar_detected(mphy->hw);
dev->hw_pattern++;
}
diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/mt7615.h b/drivers/net/wireless/mediatek/mt76/mt7615/mt7615.h
index 2e91f6a27d0f..082c73b571ae 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7615/mt7615.h
+++ b/drivers/net/wireless/mediatek/mt76/mt7615/mt7615.h
@@ -177,7 +177,6 @@ struct mt7615_phy {

u8 chfreq;
u8 rdd_state;
- int dfs_state;

u32 rx_ampdu_ts;
u32 ampdu_ref;
--
2.35.1