mt76x02: improve mac error check/reset reliability

On AP mode devices, check beacon tx counters to detect MAC errors.
When an error is detected, stop the MAC before resetting it

Signed-off-by: Felix Fietkau <[e-mail]>

drivers/net/wireless/mediatek/mt76/mt76x02.h

···
 
 	u32 tx_hang_reset;
 	u8 tx_hang_check;
+	u8 beacon_hang_check;
 	u8 mcu_timeout;
 
 	struct mt76x02_calibration cal;

drivers/net/wireless/mediatek/mt76/mt76x02_mac.c

···
 
 static void mt76x02_check_mac_err(struct mt76x02_dev *dev)
 {
-	u32 val = mt76_rr(dev, 0x10f4);
+	if (dev->mt76.beacon_mask) {
+		if (mt76_rr(dev, MT_TX_STA_0) & MT_TX_STA_0_BEACONS) {
+			dev->beacon_hang_check = 0;
+			return;
+		}
 
-	if (!(val & BIT(29)) || !(val & (BIT(7) | BIT(5))))
-		return;
+		if (++dev->beacon_hang_check < 10)
+			return;
 
-	dev_err(dev->mt76.dev, "mac specific condition occurred\n");
+		dev->beacon_hang_check = 0;
+	} else {
+		u32 val = mt76_rr(dev, 0x10f4);
+		if (!(val & BIT(29)) || !(val & (BIT(7) | BIT(5))))
+			return;
+	}
+
+	dev_err(dev->mt76.dev, "MAC error detected\n");
+
+	mt76_wr(dev, MT_MAC_SYS_CTRL, 0);
+	mt76x02_wait_for_txrx_idle(&dev->mt76);
 
 	mt76_set(dev, MT_MAC_SYS_CTRL, MT_MAC_SYS_CTRL_RESET_CSR);
 	udelay(10);
···
 		dev->mt76.aggr_stats[idx++] += val >> 16;
 	}
 
-	if (!dev->mt76.beacon_mask)
-		mt76x02_check_mac_err(dev);
+	mt76x02_check_mac_err(dev);
 
 	if (dev->ed_monitor)
 		mt76x02_edcca_check(dev);

drivers/net/wireless/mediatek/mt76/mt76x02_regs.h

···
 #define MT_RX_STAT_2_OVERFLOW_ERRORS	GENMASK(31, 16)
 
 #define MT_TX_STA_0			0x170c
+#define MT_TX_STA_0_BEACONS		GENMASK(31, 16)
+
 #define MT_TX_STA_1			0x1710
 #define MT_TX_STA_2			0x1714