smc91x: let smc91x work well under netpoll

The NETPOLL requires that interrupts remain disabled in its callbacks.

Using *_irq_save()/irq_restore() to replace *_irq_disable()/irq_enable()
functions in NETPOLL's callbacks of smc91x, so that it doesn't enable
interrupts when already disabled, and kgdboe/netconsole would work
properly over smc91x.

Signed-off-by: Dongdong Deng <dongdong.deng@windriver.com>
Acked-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/smc91x.c b/drivers/net/smc91x.c
index 1c70e99..9da1fa1 100644 (file)
--- a/drivers/net/smc91x.c
+++ b/drivers/net/smc91x.c
@@ -196,21 +196,23 @@ static void PRINT_PKT(u_char *buf, int length)
 /* this enables an interrupt in the interrupt mask register */
 #define SMC_ENABLE_INT(lp, x) do {                                     \
        unsigned char mask;                                             \
-       spin_lock_irq(&lp->lock);                                       \
+       unsigned long smc_enable_flags;                                 \
+       spin_lock_irqsave(&lp->lock, smc_enable_flags);                 \
        mask = SMC_GET_INT_MASK(lp);                                    \
        mask |= (x);                                                    \
        SMC_SET_INT_MASK(lp, mask);                                     \
-       spin_unlock_irq(&lp->lock);                                     \
+       spin_unlock_irqrestore(&lp->lock, smc_enable_flags);            \
 } while (0)
 
 /* this disables an interrupt from the interrupt mask register */
 #define SMC_DISABLE_INT(lp, x) do {                                    \
        unsigned char mask;                                             \
-       spin_lock_irq(&lp->lock);                                       \
+       unsigned long smc_disable_flags;                                \
+       spin_lock_irqsave(&lp->lock, smc_disable_flags);                \
        mask = SMC_GET_INT_MASK(lp);                                    \
        mask &= ~(x);                                                   \
        SMC_SET_INT_MASK(lp, mask);                                     \
-       spin_unlock_irq(&lp->lock);                                     \
+       spin_unlock_irqrestore(&lp->lock, smc_disable_flags);           \
 } while (0)
 
 /*
@@ -520,21 +522,21 @@ static inline void  smc_rcv(struct net_device *dev)
  * any other concurrent access and C would always interrupt B. But life
  * isn't that easy in a SMP world...
  */
-#define smc_special_trylock(lock)                                      \
+#define smc_special_trylock(lock, flags)                               \
 ({                                                                     \
        int __ret;                                                      \
-       local_irq_disable();                                            \
+       local_irq_save(flags);                                          \
        __ret = spin_trylock(lock);                                     \
        if (!__ret)                                                     \
-               local_irq_enable();                                     \
+               local_irq_restore(flags);                               \
        __ret;                                                          \
 })
-#define smc_special_lock(lock)         spin_lock_irq(lock)
-#define smc_special_unlock(lock)       spin_unlock_irq(lock)
+#define smc_special_lock(lock, flags)          spin_lock_irq(lock, flags)
+#define smc_special_unlock(lock, flags)        spin_unlock_irqrestore(lock, flags)
 #else
-#define smc_special_trylock(lock)      (1)
-#define smc_special_lock(lock)         do { } while (0)
-#define smc_special_unlock(lock)       do { } while (0)
+#define smc_special_trylock(lock, flags)       (1)
+#define smc_special_lock(lock, flags)          do { } while (0)
+#define smc_special_unlock(lock, flags)        do { } while (0)
 #endif
 
 /*
@@ -548,10 +550,11 @@ static void smc_hardware_send_pkt(unsigned long data)
        struct sk_buff *skb;
        unsigned int packet_no, len;
        unsigned char *buf;
+       unsigned long flags;
 
        DBG(3, "%s: %s\n", dev->name, __func__);
 
-       if (!smc_special_trylock(&lp->lock)) {
+       if (!smc_special_trylock(&lp->lock, flags)) {
                netif_stop_queue(dev);
                tasklet_schedule(&lp->tx_task);
                return;
@@ -559,7 +562,7 @@ static void smc_hardware_send_pkt(unsigned long data)
 
        skb = lp->pending_tx_skb;
        if (unlikely(!skb)) {
-               smc_special_unlock(&lp->lock);
+               smc_special_unlock(&lp->lock, flags);
                return;
        }
        lp->pending_tx_skb = NULL;
@@ -569,7 +572,7 @@ static void smc_hardware_send_pkt(unsigned long data)
                printk("%s: Memory allocation failed.\n", dev->name);
                dev->stats.tx_errors++;
                dev->stats.tx_fifo_errors++;
-               smc_special_unlock(&lp->lock);
+               smc_special_unlock(&lp->lock, flags);
                goto done;
        }
 
@@ -608,7 +611,7 @@ static void smc_hardware_send_pkt(unsigned long data)
 
        /* queue the packet for TX */
        SMC_SET_MMU_CMD(lp, MC_ENQUEUE);
-       smc_special_unlock(&lp->lock);
+       smc_special_unlock(&lp->lock, flags);
 
        dev->trans_start = jiffies;
        dev->stats.tx_packets++;
@@ -633,6 +636,7 @@ static int smc_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
        struct smc_local *lp = netdev_priv(dev);
        void __iomem *ioaddr = lp->base;
        unsigned int numPages, poll_count, status;
+       unsigned long flags;
 
        DBG(3, "%s: %s\n", dev->name, __func__);
 
@@ -658,7 +662,7 @@ static int smc_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
                return 0;
        }
 
-       smc_special_lock(&lp->lock);
+       smc_special_lock(&lp->lock, flags);
 
        /* now, try to allocate the memory */
        SMC_SET_MMU_CMD(lp, MC_ALLOC | numPages);
@@ -676,7 +680,7 @@ static int smc_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
                }
        } while (--poll_count);
 
-       smc_special_unlock(&lp->lock);
+       smc_special_unlock(&lp->lock, flags);
 
        lp->pending_tx_skb = skb;
        if (!poll_count) {