[PATCH 1/5] wifi: mt76: mt7603: rework/fix rx pse hang check

Felix Fietkau
2023-08-17T15:53:59Z

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