tc35815: Fix double locking on NAPI

Isolate spinlock for tx and rx to resolve double-locking.

This is potential bug while this controller does not exist on any
SMP platforms, but lockdep or rt-preempt reveals this bug.

Reported-by: Ralf Roesch <ralf.roesch@rw-gmbh.de>
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/tc35815.c b/drivers/net/tc35815.c
index 876f45afbed4329a4af82b77a0ae568fa252bc35..49bd84c0d583e4ebaf8f3df7e4de8ddd4992671f 100644 (file)
--- a/drivers/net/tc35815.c
+++ b/drivers/net/tc35815.c
@@ -402,6 +402,7 @@ struct tc35815_local {
         * by this lock as well.
         */
        spinlock_t lock;
+       spinlock_t rx_lock;
 
        struct mii_bus *mii_bus;
        struct phy_device *phy_dev;
@@ -835,6 +836,7 @@ static int __devinit tc35815_init_one(struct pci_dev *pdev,
 
        INIT_WORK(&lp->restart_work, tc35815_restart_work);
        spin_lock_init(&lp->lock);
+       spin_lock_init(&lp->rx_lock);
        lp->pci_dev = pdev;
        lp->chiptype = ent->driver_data;
 
@@ -1186,6 +1188,7 @@ static void tc35815_restart(struct net_device *dev)
                        printk(KERN_ERR "%s: BMCR reset failed.\n", dev->name);
        }
 
+       spin_lock_bh(&lp->rx_lock);
        spin_lock_irq(&lp->lock);
        tc35815_chip_reset(dev);
        tc35815_clear_queues(dev);
@@ -1193,6 +1196,7 @@ static void tc35815_restart(struct net_device *dev)
        /* Reconfigure CAM again since tc35815_chip_init() initialize it. */
        tc35815_set_multicast_list(dev);
        spin_unlock_irq(&lp->lock);
+       spin_unlock_bh(&lp->rx_lock);
 
        netif_wake_queue(dev);
 }
@@ -1211,11 +1215,14 @@ static void tc35815_schedule_restart(struct net_device *dev)
        struct tc35815_local *lp = netdev_priv(dev);
        struct tc35815_regs __iomem *tr =
                (struct tc35815_regs __iomem *)dev->base_addr;
+       unsigned long flags;
 
        /* disable interrupts */
+       spin_lock_irqsave(&lp->lock, flags);
        tc_writel(0, &tr->Int_En);
        tc_writel(tc_readl(&tr->DMA_Ctl) | DMA_IntMask, &tr->DMA_Ctl);
        schedule_work(&lp->restart_work);
+       spin_unlock_irqrestore(&lp->lock, flags);
 }
 
 static void tc35815_tx_timeout(struct net_device *dev)
@@ -1436,7 +1443,9 @@ static int tc35815_do_interrupt(struct net_device *dev, u32 status, int limit)
        if (status & Int_IntMacTx) {
                /* Transmit complete. */
                lp->lstats.tx_ints++;
+               spin_lock_irq(&lp->lock);
                tc35815_txdone(dev);
+               spin_unlock_irq(&lp->lock);
                if (ret < 0)
                        ret = 0;
        }
@@ -1649,7 +1658,7 @@ static int tc35815_poll(struct napi_struct *napi, int budget)
        int received = 0, handled;
        u32 status;
 
-       spin_lock(&lp->lock);
+       spin_lock(&lp->rx_lock);
        status = tc_readl(&tr->Int_Src);
        do {
                /* BLEx, FDAEx will be cleared later */
@@ -1667,7 +1676,7 @@ static int tc35815_poll(struct napi_struct *napi, int budget)
                }
                status = tc_readl(&tr->Int_Src);
        } while (status);
-       spin_unlock(&lp->lock);
+       spin_unlock(&lp->rx_lock);
 
        if (received < budget) {
                napi_complete(napi);