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From c007ef8c339d1eb319163bf576da0f180e162060 Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@nbd.name>
Date: Mon, 31 Jan 2022 15:04:43 +0100
Subject: [PATCH] mt76: mt76x02: improve tx hang detection
Git-commit: c007ef8c339d1eb319163bf576da0f180e162060
Patch-mainline: v5.18-rc1
References: bsc#1209980

Instead of checking if any queue has not made progress since the last run,
only trigger hang detection if one of the queues has not made any progress
in 10 subsequent runs. This should reduce false positive firmware restarts

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/net/wireless/mediatek/mt76/mt76x02.h  |  2 +-
 .../net/wireless/mediatek/mt76/mt76x02_mmio.c | 30 +++++++------------
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt76x02.h b/drivers/net/wireless/mediatek/mt76/mt76x02.h
index 3232083e9916..f76fd22ee035 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76x02.h
+++ b/drivers/net/wireless/mediatek/mt76/mt76x02.h
@@ -103,7 +103,7 @@ struct mt76x02_dev {
 	u8 tbtt_count;
 
 	u32 tx_hang_reset;
-	u8 tx_hang_check;
+	u8 tx_hang_check[4];
 	u8 beacon_hang_check;
 	u8 mcu_timeout;
 
diff --git a/drivers/net/wireless/mediatek/mt76/mt76x02_mmio.c b/drivers/net/wireless/mediatek/mt76/mt76x02_mmio.c
index ec0de691129a..8bcd8afa0d3a 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76x02_mmio.c
+++ b/drivers/net/wireless/mediatek/mt76/mt76x02_mmio.c
@@ -348,18 +348,20 @@ static bool mt76x02_tx_hang(struct mt76x02_dev *dev)
 	for (i = 0; i < 4; i++) {
 		q = dev->mphy.q_tx[i];
 
-		if (!q->queued)
-			continue;
-
 		prev_dma_idx = dev->mt76.tx_dma_idx[i];
 		dma_idx = readl(&q->regs->dma_idx);
 		dev->mt76.tx_dma_idx[i] = dma_idx;
 
-		if (prev_dma_idx == dma_idx)
-			break;
+		if (!q->queued || prev_dma_idx != dma_idx) {
+			dev->tx_hang_check[i] = 0;
+			continue;
+		}
+
+		if (++dev->tx_hang_check[i] >= MT_TX_HANG_TH)
+			return true;
 	}
 
-	return i < 4;
+	return false;
 }
 
 static void mt76x02_key_sync(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
@@ -530,23 +532,13 @@ static void mt76x02_check_tx_hang(struct mt76x02_dev *dev)
 	if (test_bit(MT76_RESTART, &dev->mphy.state))
 		return;
 
-	if (mt76x02_tx_hang(dev)) {
-		if (++dev->tx_hang_check >= MT_TX_HANG_TH)
-			goto restart;
-	} else {
-		dev->tx_hang_check = 0;
-	}
-
-	if (dev->mcu_timeout)
-		goto restart;
-
-	return;
+	if (!mt76x02_tx_hang(dev) && !dev->mcu_timeout)
+		return;
 
-restart:
 	mt76x02_watchdog_reset(dev);
 
 	dev->tx_hang_reset++;
-	dev->tx_hang_check = 0;
+	memset(dev->tx_hang_check, 0, sizeof(dev->tx_hang_check));
 	memset(dev->mt76.tx_dma_idx, 0xff,
 	       sizeof(dev->mt76.tx_dma_idx));
 }
-- 
2.35.3