mt76: mt76x02: reduce false positives in ED/CCA tx blocking

Full tx blocking (as opposed to CCA blocking) should only happen if there
is a continuous non-802.11 signal above the energy detect threshold.
Unfortunately the ED/CCA counter can't detect that, as it also counts 802.11
signals as busy.

Similar to the vendor code, implement a learning mode that waits until the AGC
gain has already been adjusted to the lowest value (due to false CCA events),
and the number of false CCA events still remains high, and the blocking
threshold is exceeded for more than 5 seconds.

Signed-off-by: Felix Fietkau <nbd@nbd.name>

diff --git a/drivers/net/wireless/mediatek/mt76/mt76x02.h b/drivers/net/wireless/mediatek/mt76/mt76x02.h
index 6915cce5def9342935784c888c477417e26b5c69..42cc9da68f7b4c7e00edadbc3522ffca7848cc3b 100644 (file)
--- a/drivers/net/wireless/mediatek/mt76/mt76x02.h
+++ b/drivers/net/wireless/mediatek/mt76/mt76x02.h
@@ -51,6 +51,7 @@ struct mt76x02_calibration {
        u16 false_cca;
        s8 avg_rssi_all;
        s8 agc_gain_adjust;
+       s8 agc_lowest_gain;
        s8 low_gain;
 
        s8 temp_vco;
@@ -114,8 +115,10 @@ struct mt76x02_dev {
        struct mt76x02_dfs_pattern_detector dfs_pd;
 
        /* edcca monitor */
+       unsigned long ed_trigger_timeout;
        bool ed_tx_blocked;
        bool ed_monitor;
+       u8 ed_monitor_learning;
        u8 ed_trigger;
        u8 ed_silent;
        ktime_t ed_time;

diff --git a/drivers/net/wireless/mediatek/mt76/mt76x02_mac.c b/drivers/net/wireless/mediatek/mt76/mt76x02_mac.c
index e1e0c8da5a8c85794fcaaf8a09c7193273aab390..9ed231abe91676119d751b06cfa995a7f5dd716c 100644 (file)
--- a/drivers/net/wireless/mediatek/mt76/mt76x02_mac.c
+++ b/drivers/net/wireless/mediatek/mt76/mt76x02_mac.c
@@ -960,6 +960,7 @@ void mt76x02_edcca_init(struct mt76x02_dev *dev, bool enable)
                }
        }
        mt76x02_edcca_tx_enable(dev, true);
+       dev->ed_monitor_learning = true;
 
        /* clear previous CCA timer value */
        mt76_rr(dev, MT_ED_CCA_TIMER);
@@ -969,6 +970,10 @@ EXPORT_SYMBOL_GPL(mt76x02_edcca_init);
 
 #define MT_EDCCA_TH            92
 #define MT_EDCCA_BLOCK_TH      2
+#define MT_EDCCA_LEARN_TH      50
+#define MT_EDCCA_LEARN_CCA     180
+#define MT_EDCCA_LEARN_TIMEOUT (20 * HZ)
+
 static void mt76x02_edcca_check(struct mt76x02_dev *dev)
 {
        ktime_t cur_time;
@@ -991,11 +996,23 @@ static void mt76x02_edcca_check(struct mt76x02_dev *dev)
                dev->ed_trigger = 0;
        }
 
-       if (dev->ed_trigger > MT_EDCCA_BLOCK_TH &&
-           !dev->ed_tx_blocked)
+       if (dev->cal.agc_lowest_gain &&
+           dev->cal.false_cca > MT_EDCCA_LEARN_CCA &&
+           dev->ed_trigger > MT_EDCCA_LEARN_TH) {
+               dev->ed_monitor_learning = false;
+               dev->ed_trigger_timeout = jiffies + 20 * HZ;
+       } else if (!dev->ed_monitor_learning &&
+                  time_is_after_jiffies(dev->ed_trigger_timeout)) {
+               dev->ed_monitor_learning = true;
+               mt76x02_edcca_tx_enable(dev, true);
+       }
+
+       if (dev->ed_monitor_learning)
+               return;
+
+       if (dev->ed_trigger > MT_EDCCA_BLOCK_TH && !dev->ed_tx_blocked)
                mt76x02_edcca_tx_enable(dev, false);
-       else if (dev->ed_silent > MT_EDCCA_BLOCK_TH &&
-                dev->ed_tx_blocked)
+       else if (dev->ed_silent > MT_EDCCA_BLOCK_TH && dev->ed_tx_blocked)
                mt76x02_edcca_tx_enable(dev, true);
 }
 

diff --git a/drivers/net/wireless/mediatek/mt76/mt76x02_phy.c b/drivers/net/wireless/mediatek/mt76/mt76x02_phy.c
index a020c757ba5c6c59fba0463d01f5774a916e4339..a54b63a96eaefa24268f28573f1123c30ee6b9d5 100644 (file)
--- a/drivers/net/wireless/mediatek/mt76/mt76x02_phy.c
+++ b/drivers/net/wireless/mediatek/mt76/mt76x02_phy.c
@@ -194,6 +194,8 @@ bool mt76x02_phy_adjust_vga_gain(struct mt76x02_dev *dev)
                ret = true;
        }
 
+       dev->cal.agc_lowest_gain = dev->cal.agc_gain_adjust >= limit;
+
        return ret;
 }
 EXPORT_SYMBOL_GPL(mt76x02_phy_adjust_vga_gain);