wifi: mt76: mt7603: improve stuck beacon handling

Before preparing the new beacon, check the queue status, flush out all
previous beacons and buffered multicast packets, then (if necessary)
try to recover more gracefully from a stuck beacon condition by making a
less invasive attempt at getting the MAC un-stuck.

Fixes: c8846e10 ("mt76: add driver for MT7603E and MT7628/7688")
Signed-off-by: Felix Fietkau <nbd@nbd.name>

drivers/net/wireless/mediatek/mt76/mt7603/beacon.c

@@ -9,6 +9,23 @@ struct beacon_bc_data {
 	int count[MT7603_MAX_INTERFACES];
 };
 
+static void
+mt7603_mac_stuck_beacon_recovery(struct mt7603_dev *dev)
+{
+	if (dev->beacon_check % 5 != 4)
+		return;
+
+	mt76_clear(dev, MT_WPDMA_GLO_CFG, MT_WPDMA_GLO_CFG_TX_DMA_EN);
+	mt76_set(dev, MT_SCH_4, MT_SCH_4_RESET);
+	mt76_clear(dev, MT_SCH_4, MT_SCH_4_RESET);
+	mt76_set(dev, MT_WPDMA_GLO_CFG, MT_WPDMA_GLO_CFG_TX_DMA_EN);
+
+	mt76_set(dev, MT_WF_CFG_OFF_WOCCR, MT_WF_CFG_OFF_WOCCR_TMAC_GC_DIS);
+	mt76_set(dev, MT_ARB_SCR, MT_ARB_SCR_TX_DISABLE);
+	mt76_clear(dev, MT_ARB_SCR, MT_ARB_SCR_TX_DISABLE);
+	mt76_clear(dev, MT_WF_CFG_OFF_WOCCR, MT_WF_CFG_OFF_WOCCR_TMAC_GC_DIS);
+}
+
 static void
 mt7603_update_beacon_iter(void *priv, u8 *mac, struct ieee80211_vif *vif)
 {
@@ -16,6 +33,8 @@ mt7603_update_beacon_iter(void *priv, u8 *mac, struct ieee80211_vif *vif)
 	struct mt76_dev *mdev = &dev->mt76;
 	struct mt7603_vif *mvif = (struct mt7603_vif *)vif->drv_priv;
 	struct sk_buff *skb = NULL;
+	u32 om_idx = mvif->idx;
+	u32 val;
 
 	if (!(mdev->beacon_mask & BIT(mvif->idx)))
 		return;
@@ -24,20 +43,33 @@ mt7603_update_beacon_iter(void *priv, u8 *mac, struct ieee80211_vif *vif)
 	if (!skb)
 		return;
 
-	mt76_tx_queue_skb(dev, dev->mphy.q_tx[MT_TXQ_BEACON],
-			  MT_TXQ_BEACON, skb, &mvif->sta.wcid, NULL);
+	if (om_idx)
+		om_idx |= 0x10;
+	val = MT_DMA_FQCR0_BUSY | MT_DMA_FQCR0_MODE |
+		FIELD_PREP(MT_DMA_FQCR0_TARGET_BSS, om_idx) |
+		FIELD_PREP(MT_DMA_FQCR0_DEST_PORT_ID, 3) |
+		FIELD_PREP(MT_DMA_FQCR0_DEST_QUEUE_ID, 8);
 
 	spin_lock_bh(&dev->ps_lock);
-	mt76_wr(dev, MT_DMA_FQCR0, MT_DMA_FQCR0_BUSY |
-		FIELD_PREP(MT_DMA_FQCR0_TARGET_WCID, mvif->sta.wcid.idx) |
-		FIELD_PREP(MT_DMA_FQCR0_TARGET_QID,
-			   dev->mphy.q_tx[MT_TXQ_CAB]->hw_idx) |
-		FIELD_PREP(MT_DMA_FQCR0_DEST_PORT_ID, 3) |
-		FIELD_PREP(MT_DMA_FQCR0_DEST_QUEUE_ID, 8));
 
-	if (!mt76_poll(dev, MT_DMA_FQCR0, MT_DMA_FQCR0_BUSY, 0, 5000))
+	mt76_wr(dev, MT_DMA_FQCR0, val |
+		FIELD_PREP(MT_DMA_FQCR0_TARGET_QID, MT_TX_HW_QUEUE_BCN));
+	if (!mt76_poll(dev, MT_DMA_FQCR0, MT_DMA_FQCR0_BUSY, 0, 5000)) {
 		dev->beacon_check = MT7603_WATCHDOG_TIMEOUT;
+		goto out;
+	}
+
+	mt76_wr(dev, MT_DMA_FQCR0, val |
+		FIELD_PREP(MT_DMA_FQCR0_TARGET_QID, MT_TX_HW_QUEUE_BMC));
+	if (!mt76_poll(dev, MT_DMA_FQCR0, MT_DMA_FQCR0_BUSY, 0, 5000)) {
+		dev->beacon_check = MT7603_WATCHDOG_TIMEOUT;
+		goto out;
+	}
 
+	mt76_tx_queue_skb(dev, dev->mphy.q_tx[MT_TXQ_BEACON],
+			  MT_TXQ_BEACON, skb, &mvif->sta.wcid, NULL);
+
+out:
 	spin_unlock_bh(&dev->ps_lock);
 }
 
@@ -81,6 +113,18 @@ void mt7603_pre_tbtt_tasklet(struct tasklet_struct *t)
 	data.dev = dev;
 	__skb_queue_head_init(&data.q);
 
+	/* Flush all previous CAB queue packets and beacons */
+	mt76_wr(dev, MT_WF_ARB_CAB_FLUSH, GENMASK(30, 16) | BIT(0));
+
+	mt76_queue_tx_cleanup(dev, dev->mphy.q_tx[MT_TXQ_CAB], false);
+	mt76_queue_tx_cleanup(dev, dev->mphy.q_tx[MT_TXQ_BEACON], false);
+
+	if (dev->mphy.q_tx[MT_TXQ_BEACON]->queued > 0)
+		dev->beacon_check++;
+	else
+		dev->beacon_check = 0;
+	mt7603_mac_stuck_beacon_recovery(dev);
+
 	q = dev->mphy.q_tx[MT_TXQ_BEACON];
 	spin_lock(&q->lock);
 	ieee80211_iterate_active_interfaces_atomic(mt76_hw(dev),
@@ -89,14 +133,9 @@ void mt7603_pre_tbtt_tasklet(struct tasklet_struct *t)
 	mt76_queue_kick(dev, q);
 	spin_unlock(&q->lock);
 
-	/* Flush all previous CAB queue packets */
-	mt76_wr(dev, MT_WF_ARB_CAB_FLUSH, GENMASK(30, 16) | BIT(0));
-
-	mt76_queue_tx_cleanup(dev, dev->mphy.q_tx[MT_TXQ_CAB], false);
-
 	mt76_csa_check(mdev);
 	if (mdev->csa_complete)
-		goto out;
+		return;
 
 	q = dev->mphy.q_tx[MT_TXQ_CAB];
 	do {
@@ -108,7 +147,7 @@ void mt7603_pre_tbtt_tasklet(struct tasklet_struct *t)
 		 skb_queue_len(&data.q) < 8);
 
 	if (skb_queue_empty(&data.q))
-		goto out;
+		return;
 
 	for (i = 0; i < ARRAY_SIZE(data.tail); i++) {
 		if (!data.tail[i])
@@ -136,11 +175,6 @@ void mt7603_pre_tbtt_tasklet(struct tasklet_struct *t)
 		MT_WF_ARB_CAB_START_BSSn(0) |
 		(MT_WF_ARB_CAB_START_BSS0n(1) *
 		 ((1 << (MT7603_MAX_INTERFACES - 1)) - 1)));
-
-out:
-	mt76_queue_tx_cleanup(dev, dev->mphy.q_tx[MT_TXQ_BEACON], false);
-	if (dev->mphy.q_tx[MT_TXQ_BEACON]->queued > hweight8(mdev->beacon_mask))
-		dev->beacon_check++;
 }
 
 void mt7603_beacon_set_timer(struct mt7603_dev *dev, int idx, int intval)

drivers/net/wireless/mediatek/mt76/mt7603/regs.h

@@ -469,6 +469,11 @@ enum {
 #define MT_WF_SEC_BASE			0x21a00
 #define MT_WF_SEC(ofs)			(MT_WF_SEC_BASE + (ofs))
 
+#define MT_WF_CFG_OFF_BASE		0x21e00
+#define MT_WF_CFG_OFF(ofs)		(MT_WF_CFG_OFF_BASE + (ofs))
+#define MT_WF_CFG_OFF_WOCCR		MT_WF_CFG_OFF(0x004)
+#define MT_WF_CFG_OFF_WOCCR_TMAC_GC_DIS	BIT(4)
+
 #define MT_SEC_SCR			MT_WF_SEC(0x004)
 #define MT_SEC_SCR_MASK_ORDER		GENMASK(1, 0)