netpoll: drivers must not enable IRQ unconditionally in their NAPI handler
Francois Romieu [Sun, 17 Dec 2006 22:03:15 +0000 (23:03 +0100)]
net/core/netpoll.c::netpoll_send_skb() calls the poll handler when
it is available. As netconsole can be used from almost any context,
IRQ must not be enabled blindly in the NAPI handler of a driver which
supports netpoll.

b57bd06655a028aba7b92e1c19c2093e7fcfb341 fixed the issue for the
8139too.c driver.

Signed-off-by: Francois Romieu <romieu@fr.zoreil.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

drivers/net/8139cp.c
drivers/net/b44.c
drivers/net/forcedeth.c
drivers/net/skge.c

index 458dd9f..e2cb19b 100644 (file)
@@ -617,13 +617,15 @@ rx_next:
         * this round of polling
         */
        if (rx_work) {
+               unsigned long flags;
+
                if (cpr16(IntrStatus) & cp_rx_intr_mask)
                        goto rx_status_loop;
 
-               local_irq_disable();
+               local_irq_save(flags);
                cpw16_f(IntrMask, cp_intr_mask);
                __netif_rx_complete(dev);
-               local_irq_enable();
+               local_irq_restore(flags);
 
                return 0;       /* done */
        }
index 474a4e3..5eb2ec6 100644 (file)
@@ -879,12 +879,14 @@ static int b44_poll(struct net_device *netdev, int *budget)
        }
 
        if (bp->istat & ISTAT_ERRORS) {
-               spin_lock_irq(&bp->lock);
+               unsigned long flags;
+
+               spin_lock_irqsave(&bp->lock, flags);
                b44_halt(bp);
                b44_init_rings(bp);
                b44_init_hw(bp, 1);
                netif_wake_queue(bp->dev);
-               spin_unlock_irq(&bp->lock);
+               spin_unlock_irqrestore(&bp->lock, flags);
                done = 1;
        }
 
index 439f413..820f8c7 100644 (file)
@@ -2576,14 +2576,15 @@ static int nv_napi_poll(struct net_device *dev, int *budget)
        int pkts, limit = min(*budget, dev->quota);
        struct fe_priv *np = netdev_priv(dev);
        u8 __iomem *base = get_hwbase(dev);
+       unsigned long flags;
 
        pkts = nv_rx_process(dev, limit);
 
        if (nv_alloc_rx(dev)) {
-               spin_lock_irq(&np->lock);
+               spin_lock_irqsave(&np->lock, flags);
                if (!np->in_shutdown)
                        mod_timer(&np->oom_kick, jiffies + OOM_REFILL);
-               spin_unlock_irq(&np->lock);
+               spin_unlock_irqrestore(&np->lock, flags);
        }
 
        if (pkts < limit) {
@@ -2591,13 +2592,15 @@ static int nv_napi_poll(struct net_device *dev, int *budget)
                netif_rx_complete(dev);
 
                /* re-enable receive interrupts */
-               spin_lock_irq(&np->lock);
+               spin_lock_irqsave(&np->lock, flags);
+
                np->irqmask |= NVREG_IRQ_RX_ALL;
                if (np->msi_flags & NV_MSI_X_ENABLED)
                        writel(NVREG_IRQ_RX_ALL, base + NvRegIrqMask);
                else
                        writel(np->irqmask, base + NvRegIrqMask);
-               spin_unlock_irq(&np->lock);
+
+               spin_unlock_irqrestore(&np->lock, flags);
                return 0;
        } else {
                /* used up our quantum, so reschedule */
index 8a39376..deedfd5 100644 (file)
@@ -2920,6 +2920,7 @@ static int skge_poll(struct net_device *dev, int *budget)
        struct skge_hw *hw = skge->hw;
        struct skge_ring *ring = &skge->rx_ring;
        struct skge_element *e;
+       unsigned long flags;
        int to_do = min(dev->quota, *budget);
        int work_done = 0;
 
@@ -2957,12 +2958,12 @@ static int skge_poll(struct net_device *dev, int *budget)
        if (work_done >=  to_do)
                return 1; /* not done */
 
-       spin_lock_irq(&hw->hw_lock);
+       spin_lock_irqsave(&hw->hw_lock, flags);
        __netif_rx_complete(dev);
        hw->intr_mask |= irqmask[skge->port];
        skge_write32(hw, B0_IMSK, hw->intr_mask);
        skge_read32(hw, B0_IMSK);
-       spin_unlock_irq(&hw->hw_lock);
+       spin_unlock_irqrestore(&hw->hw_lock, flags);
 
        return 0;
 }