From: Lorenzo Bianconi <lorenzo@kernel.org>
To: Felix Fietkau <nbd@nbd.name>
Cc: linux-wireless@vger.kernel.org, Soul Huang <Soul.Huang@mediatek.com>
Subject: Re: [PATCH] mt76: mt7615: rework IRQ handling to prepare for MSI support
Date: Thu, 9 Apr 2020 18:18:48 +0200 [thread overview]
Message-ID: <20200409161848.GB6385@lore-desk-wlan> (raw)
In-Reply-To: <20200409155902.58185-1-nbd@nbd.name>
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> 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>
> Signed-off-by: Felix Fietkau <nbd@nbd.name>
Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>
> ---
> drivers/net/wireless/mediatek/mt76/mmio.c | 3 +-
> .../net/wireless/mediatek/mt76/mt7615/init.c | 2 ++
> .../net/wireless/mediatek/mt76/mt7615/mmio.c | 30 +++++++++++++------
> .../wireless/mediatek/mt76/mt7615/mt7615.h | 9 +++---
> 4 files changed, 29 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/net/wireless/mediatek/mt76/mmio.c b/drivers/net/wireless/mediatek/mt76/mmio.c
> index 7ead6620bb8b..26353b6bce97 100644
> --- 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 96b7c6284833..cb626a2d9197 100644
> --- 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 3849bb6b49d0..58506dc423ab 100644
> --- a/drivers/net/wireless/mediatek/mt76/mt7615/mmio.c
> +++ b/drivers/net/wireless/mediatek/mt76/mt7615/mmio.c
> @@ -80,30 +80,41 @@ 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);
>
> if (!test_bit(MT76_STATE_INITIALIZED, &dev->mphy.state))
> return IRQ_NONE;
>
> - trace_dev_irq(&dev->mt76, intr, dev->mt76.mmio.irqmask);
> + mt76_wr(dev, MT_INT_MASK_CSR, 0);
> + 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 +128,7 @@ 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 +165,7 @@ 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 4f0d29e5e595..10a98d38f77e 100644
> --- 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)
> --
> 2.24.0
>
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next prev parent reply other threads:[~2020-04-09 16:18 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-09 15:59 [PATCH] mt76: mt7615: rework IRQ handling to prepare for MSI support Felix Fietkau
2020-04-09 16:18 ` Lorenzo Bianconi [this message]
2020-04-14 6:32 ` Kalle Valo
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