2006-02-27 22:31:51

by Chris Wright

[permalink] [raw]
Subject: [patch 32/39] [PATCH] skge: fix SMP race

-stable review patch. If anyone has any objections, please let us know.
------------------

If skge is attached to a bad cable, that goes up/down.
It exposes an SMP race with the management of IRQ mask

Signed-off-by: Stephen Hemminger <[email protected]>
Signed-off-by: Chris Wright <[email protected]>
---

drivers/net/skge.c | 21 ++++++++++++++-------
drivers/net/skge.h | 1 +
2 files changed, 15 insertions(+), 7 deletions(-)

--- linux-2.6.15.4.orig/drivers/net/skge.c
+++ linux-2.6.15.4/drivers/net/skge.c
@@ -2182,8 +2182,10 @@ static int skge_up(struct net_device *de
skge->tx_avail = skge->tx_ring.count - 1;

/* Enable IRQ from port */
+ spin_lock_irq(&hw->hw_lock);
hw->intr_mask |= portirqmask[port];
skge_write32(hw, B0_IMSK, hw->intr_mask);
+ spin_unlock_irq(&hw->hw_lock);

/* Initialize MAC */
spin_lock_bh(&hw->phy_lock);
@@ -2241,8 +2243,10 @@ static int skge_down(struct net_device *
else
yukon_stop(skge);

+ spin_lock_irq(&hw->hw_lock);
hw->intr_mask &= ~portirqmask[skge->port];
skge_write32(hw, B0_IMSK, hw->intr_mask);
+ spin_unlock_irq(&hw->hw_lock);

/* Stop transmitter */
skge_write8(hw, Q_ADDR(txqaddr[port], Q_CSR), CSR_STOP);
@@ -2698,10 +2702,11 @@ static int skge_poll(struct net_device *
if (work_done >= to_do)
return 1; /* not done */

- netif_rx_complete(dev);
- hw->intr_mask |= portirqmask[skge->port];
- skge_write32(hw, B0_IMSK, hw->intr_mask);
- skge_read32(hw, B0_IMSK);
+ spin_lock_irq(&hw->hw_lock);
+ __netif_rx_complete(dev);
+ hw->intr_mask |= portirqmask[skge->port];
+ skge_write32(hw, B0_IMSK, hw->intr_mask);
+ spin_unlock_irq(&hw->hw_lock);

return 0;
}
@@ -2861,10 +2866,10 @@ static void skge_extirq(unsigned long da
}
spin_unlock(&hw->phy_lock);

- local_irq_disable();
+ spin_lock_irq(&hw->hw_lock);
hw->intr_mask |= IS_EXT_REG;
skge_write32(hw, B0_IMSK, hw->intr_mask);
- local_irq_enable();
+ spin_unlock_irq(&hw->hw_lock);
}

static irqreturn_t skge_intr(int irq, void *dev_id, struct pt_regs *regs)
@@ -2875,7 +2880,7 @@ static irqreturn_t skge_intr(int irq, vo
if (status == 0 || status == ~0) /* hotplug or shared irq */
return IRQ_NONE;

- status &= hw->intr_mask;
+ spin_lock(&hw->hw_lock);
if (status & IS_R1_F) {
skge_write8(hw, Q_ADDR(Q_R1, Q_CSR), CSR_IRQ_CL_F);
hw->intr_mask &= ~IS_R1_F;
@@ -2927,6 +2932,7 @@ static irqreturn_t skge_intr(int irq, vo
}

skge_write32(hw, B0_IMSK, hw->intr_mask);
+ spin_unlock(&hw->hw_lock);

return IRQ_HANDLED;
}
@@ -3285,6 +3291,7 @@ static int __devinit skge_probe(struct p

hw->pdev = pdev;
spin_lock_init(&hw->phy_lock);
+ spin_lock_init(&hw->hw_lock);
tasklet_init(&hw->ext_tasklet, skge_extirq, (unsigned long) hw);

hw->regs = ioremap_nocache(pci_resource_start(pdev, 0), 0x4000);
--- linux-2.6.15.4.orig/drivers/net/skge.h
+++ linux-2.6.15.4/drivers/net/skge.h
@@ -2473,6 +2473,7 @@ struct skge_hw {

struct tasklet_struct ext_tasklet;
spinlock_t phy_lock;
+ spinlock_t hw_lock;
};

enum {

--