mt76: mt7615: rework IRQ handling to prepare for MSI support

With MSI interrupts, IRQs must not be enabled from within the IRQ handler,
because that can lead to lost events.
Defer IRQ processing to a tasklet, which is also responsible for enabling
IRQs (to avoid race conditions against the handler)

Co-developed-by: Soul Huang <Soul.Huang@mediatek.com>
Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Soul Huang <soul.huang@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

diff --git a/drivers/net/wireless/mediatek/mt76/mmio.c b/drivers/net/wireless/mediatek/mt76/mmio.c
index 7ead6620bb8b8c0aaeaebca9c78304e7e5c4690a..26353b6bce976f797896c42edbc669d0ffac482c 100644 (file)
--- a/drivers/net/wireless/mediatek/mt76/mmio.c
+++ b/drivers/net/wireless/mediatek/mt76/mmio.c
@@ -73,7 +73,8 @@ void mt76_set_irq_mask(struct mt76_dev *dev, u32 addr,
        spin_lock_irqsave(&dev->mmio.irq_lock, flags);
        dev->mmio.irqmask &= ~clear;
        dev->mmio.irqmask |= set;
-       mt76_mmio_wr(dev, addr, dev->mmio.irqmask);
+       if (addr)
+               mt76_mmio_wr(dev, addr, dev->mmio.irqmask);
        spin_unlock_irqrestore(&dev->mmio.irq_lock, flags);
 }
 EXPORT_SYMBOL_GPL(mt76_set_irq_mask);

diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/init.c b/drivers/net/wireless/mediatek/mt76/mt7615/init.c
index 96b7c6284833b498e9ba30b440afec530097372a..cb626a2d919735dd2990a552b757a7100aae5912 100644 (file)
--- a/drivers/net/wireless/mediatek/mt76/mt7615/init.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7615/init.c
@@ -561,5 +561,7 @@ void mt7615_unregister_device(struct mt7615_dev *dev)
        spin_unlock_bh(&dev->token_lock);
        idr_destroy(&dev->token);
 
+       tasklet_disable(&dev->irq_tasklet);
+
        mt76_free_device(&dev->mt76);
 }

diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/mmio.c b/drivers/net/wireless/mediatek/mt76/mt7615/mmio.c
index 3849bb6b49d038826e9d5710018701c04403aab4..e9f9cda6bb5900f5531817ce2da53de35542f1e9 100644 (file)
--- a/drivers/net/wireless/mediatek/mt76/mt7615/mmio.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7615/mmio.c
@@ -80,30 +80,42 @@ mt7615_rx_poll_complete(struct mt76_dev *mdev, enum mt76_rxq_id q)
 static irqreturn_t mt7615_irq_handler(int irq, void *dev_instance)
 {
        struct mt7615_dev *dev = dev_instance;
-       u32 intr;
 
-       intr = mt76_rr(dev, MT_INT_SOURCE_CSR);
-       mt76_wr(dev, MT_INT_SOURCE_CSR, intr);
+       mt76_wr(dev, MT_INT_MASK_CSR, 0);
 
        if (!test_bit(MT76_STATE_INITIALIZED, &dev->mphy.state))
                return IRQ_NONE;
 
-       trace_dev_irq(&dev->mt76, intr, dev->mt76.mmio.irqmask);
+       tasklet_schedule(&dev->irq_tasklet);
+
+       return IRQ_HANDLED;
+}
+
+static void mt7615_irq_tasklet(unsigned long data)
+{
+       struct mt7615_dev *dev = (struct mt7615_dev *)data;
+       u32 intr, mask = 0;
+
+       mt76_wr(dev, MT_INT_MASK_CSR, 0);
 
+       intr = mt76_rr(dev, MT_INT_SOURCE_CSR);
+       mt76_wr(dev, MT_INT_SOURCE_CSR, intr);
+
+       trace_dev_irq(&dev->mt76, intr, dev->mt76.mmio.irqmask);
        intr &= dev->mt76.mmio.irqmask;
 
        if (intr & MT_INT_TX_DONE_ALL) {
-               mt7615_irq_disable(dev, MT_INT_TX_DONE_ALL);
+               mask |= MT_INT_TX_DONE_ALL;
                napi_schedule(&dev->mt76.tx_napi);
        }
 
        if (intr & MT_INT_RX_DONE(0)) {
-               mt7615_irq_disable(dev, MT_INT_RX_DONE(0));
+               mask |= MT_INT_RX_DONE(0);
                napi_schedule(&dev->mt76.napi[0]);
        }
 
        if (intr & MT_INT_RX_DONE(1)) {
-               mt7615_irq_disable(dev, MT_INT_RX_DONE(1));
+               mask |= MT_INT_RX_DONE(1);
                napi_schedule(&dev->mt76.napi[1]);
        }
 
@@ -117,7 +129,7 @@ static irqreturn_t mt7615_irq_handler(int irq, void *dev_instance)
                }
        }
 
-       return IRQ_HANDLED;
+       mt76_set_irq_mask(&dev->mt76, MT_INT_MASK_CSR, mask, 0);
 }
 
 int mt7615_mmio_probe(struct device *pdev, void __iomem *mem_base,
@@ -154,6 +166,7 @@ int mt7615_mmio_probe(struct device *pdev, void __iomem *mem_base,
 
        dev = container_of(mdev, struct mt7615_dev, mt76);
        mt76_mmio_init(&dev->mt76, mem_base);
+       tasklet_init(&dev->irq_tasklet, mt7615_irq_tasklet, (unsigned long)dev);
 
        dev->reg_map = map;
        dev->ops = ops;

diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/mt7615.h b/drivers/net/wireless/mediatek/mt76/mt7615/mt7615.h
index 4f0d29e5e5957b294d5423213e77aaec7ff248de..10a98d38f77ea025b0c99f1f068c2214b514897f 100644 (file)
--- a/drivers/net/wireless/mediatek/mt76/mt7615/mt7615.h
+++ b/drivers/net/wireless/mediatek/mt76/mt7615/mt7615.h
@@ -229,6 +229,8 @@ struct mt7615_dev {
                struct mt76_phy mphy;
        };
 
+       struct tasklet_struct irq_tasklet;
+
        struct mt7615_phy phy;
        u32 vif_mask;
        u32 omac_mask;
@@ -404,12 +406,9 @@ static inline bool is_mt7663(struct mt76_dev *dev)
 
 static inline void mt7615_irq_enable(struct mt7615_dev *dev, u32 mask)
 {
-       mt76_set_irq_mask(&dev->mt76, MT_INT_MASK_CSR, 0, mask);
-}
+       mt76_set_irq_mask(&dev->mt76, 0, 0, mask);
 
-static inline void mt7615_irq_disable(struct mt7615_dev *dev, u32 mask)
-{
-       mt76_set_irq_mask(&dev->mt76, MT_INT_MASK_CSR, mask, 0);
+       tasklet_schedule(&dev->irq_tasklet);
 }
 
 static inline bool mt7615_firmware_offload(struct mt7615_dev *dev)