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From:   Felix Fietkau <nbd@nbd.name>
To:     linux-wireless@vger.kernel.org
Subject: [PATCH 1/5] wifi: mt76: mt7603: rework/fix rx pse hang check
Date:   Thu, 17 Aug 2023 17:52:54 +0200
Message-ID: <20230817155258.62636-1-nbd@nbd.name>
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It turns out that the code in mt7603_rx_pse_busy() does not detect actual
hardware hangs, it only checks for busy conditions in PSE.
A reset should only be performed if these conditions are true and if there
is no rx activity as well.
Reset the counter whenever a rx interrupt occurs. In order to also deal with
a fully loaded CPU that leaves interrupts disabled with continuous NAPI
polling, also check for pending rx interrupts in the function itself.

Fixes: c8846e101502 ("mt76: add driver for MT7603E and MT7628/7688")
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
 .../net/wireless/mediatek/mt76/mt7603/core.c  |  2 ++
 .../net/wireless/mediatek/mt76/mt7603/mac.c   | 23 +++++++++++++------
 2 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7603/core.c b/drivers/net/wireless/mediatek/mt76/mt7603/core.c
index 60a996b63c0c..915b8349146a 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7603/core.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7603/core.c
@@ -42,11 +42,13 @@ irqreturn_t mt7603_irq_handler(int irq, void *dev_instance)
 	}
 
 	if (intr & MT_INT_RX_DONE(0)) {
+		dev->rx_pse_check = 0;
 		mt7603_irq_disable(dev, MT_INT_RX_DONE(0));
 		napi_schedule(&dev->mt76.napi[0]);
 	}
 
 	if (intr & MT_INT_RX_DONE(1)) {
+		dev->rx_pse_check = 0;
 		mt7603_irq_disable(dev, MT_INT_RX_DONE(1));
 		napi_schedule(&dev->mt76.napi[1]);
 	}
diff --git a/drivers/net/wireless/mediatek/mt76/mt7603/mac.c b/drivers/net/wireless/mediatek/mt76/mt7603/mac.c
index 99ae080502d8..7a506a0c46e2 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7603/mac.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7603/mac.c
@@ -1570,20 +1570,29 @@ static bool mt7603_rx_pse_busy(struct mt7603_dev *dev)
 {
 	u32 addr, val;
 
-	if (mt76_rr(dev, MT_MCU_DEBUG_RESET) & MT_MCU_DEBUG_RESET_QUEUES)
-		return true;
-
 	if (mt7603_rx_fifo_busy(dev))
-		return false;
+		goto out;
 
 	addr = mt7603_reg_map(dev, MT_CLIENT_BASE_PHYS_ADDR + MT_CLIENT_STATUS);
 	mt76_wr(dev, addr, 3);
 	val = mt76_rr(dev, addr) >> 16;
 
-	if (is_mt7628(dev) && (val & 0x4001) == 0x4001)
-		return true;
+	if (!(val & BIT(0)))
+		return false;
+
+	if (is_mt7628(dev))
+		val &= 0xa000;
+	else
+		val &= 0x8000;
+	if (!val)
+		return false;
+
+out:
+	if (mt76_rr(dev, MT_INT_SOURCE_CSR) &
+	    (MT_INT_RX_DONE(0) | MT_INT_RX_DONE(1)))
+		return false;
 
-	return (val & 0x8001) == 0x8001 || (val & 0xe001) == 0xe001;
+	return true;
 }
 
 static bool
-- 
2.41.0