[PATCH 5/8] mt76: mt76x02: issue watchdog reset on MCU request timeout

[Felix Fietkau]

MCU request timeout usually indicates that the device is no longer responsive,
and it usually does not recover without a reset

Signed-off-by: Felix Fietkau <n...@nbd.name>
---
 drivers/net/wireless/mediatek/mt76/mt76x02.h  |  1 +
 .../net/wireless/mediatek/mt76/mt76x02_mcu.c  |  1 +
 .../net/wireless/mediatek/mt76/mt76x02_mmio.c | 28 +++++++++++++------
 3 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt76x02.h 
b/drivers/net/wireless/mediatek/mt76/mt76x02.h
index 3464b4ca2ea8..6915cce5def9 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76x02.h
+++ b/drivers/net/wireless/mediatek/mt76/mt76x02.h
@@ -98,6 +98,7 @@ struct mt76x02_dev {
 
        u32 tx_hang_reset;
        u8 tx_hang_check;
+       u8 mcu_timeout;
 
        struct mt76x02_calibration cal;
 
diff --git a/drivers/net/wireless/mediatek/mt76/mt76x02_mcu.c 
b/drivers/net/wireless/mediatek/mt76/mt76x02_mcu.c
index 4752c104abf3..6501b853b65c 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76x02_mcu.c
+++ b/drivers/net/wireless/mediatek/mt76/mt76x02_mcu.c
@@ -61,6 +61,7 @@ int mt76x02_mcu_msg_send(struct mt76_dev *mdev, int cmd, 
const void *data,
                                "MCU message %d (seq %d) timed out\n", cmd,
                                seq);
                        ret = -ETIMEDOUT;
+                       dev->mcu_timeout = 1;
                        break;
                }
 
diff --git a/drivers/net/wireless/mediatek/mt76/mt76x02_mmio.c 
b/drivers/net/wireless/mediatek/mt76/mt76x02_mmio.c
index f0198eea2bb8..1229f19f2b02 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76x02_mmio.c
+++ b/drivers/net/wireless/mediatek/mt76/mt76x02_mmio.c
@@ -494,18 +494,28 @@ static void mt76x02_watchdog_reset(struct mt76x02_dev 
*dev)
 static void mt76x02_check_tx_hang(struct mt76x02_dev *dev)
 {
        if (mt76x02_tx_hang(dev)) {
-               if (++dev->tx_hang_check < MT_TX_HANG_TH)
-                       return;
-
-               mt76x02_watchdog_reset(dev);
-
-               dev->tx_hang_reset++;
-               dev->tx_hang_check = 0;
-               memset(dev->mt76.tx_dma_idx, 0xff,
-                      sizeof(dev->mt76.tx_dma_idx));
+               if (++dev->tx_hang_check >= MT_TX_HANG_TH)
+                       goto restart;
        } else {
                dev->tx_hang_check = 0;
        }
+
+       if (dev->mcu_timeout)
+               goto restart;
+
+       return;
+
+restart:
+       mt76x02_watchdog_reset(dev);
+
+       mutex_lock(&dev->mt76.mmio.mcu.mutex);
+       dev->mcu_timeout = 0;
+       mutex_unlock(&dev->mt76.mmio.mcu.mutex);
+
+       dev->tx_hang_reset++;
+       dev->tx_hang_check = 0;
+       memset(dev->mt76.tx_dma_idx, 0xff,
+              sizeof(dev->mt76.tx_dma_idx));
 }
 
 void mt76x02_wdt_work(struct work_struct *work)
-- 
2.17.0