netpoll: drivers must not enable IRQ unconditionally in their NAPI handler

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>

1 files changed, 7 insertions, 4 deletions

diff --git a/drivers/net/forcedeth.c b/drivers/net/forcedeth.c
index 439f41338291..820f8c798420 100644
--- a/drivers/net/forcedeth.c
+++ b/drivers/net/forcedeth.c
@@ -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 */