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>

1 files changed, 11 insertions, 2 deletions

diff --git a/drivers/net/tc35815.c b/drivers/net/tc35815.c
index 876f45afbed4..49bd84c0d583 100644
--- 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);