[PATCH] sky2: reschedule if irq still pending

This is a workaround for the case edge-triggered irq's. Several users
seem to have broken configurations sharing edge-triggered irq's. To avoid
losing IRQ's, reshedule if more work arrives.

The changes to netdevice.h are to extract the part that puts device
back in list into separate inline.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c
index 67b0eab16589e57e96f473c11937b63a97e31556..618fde8622ca6a3766803ac5facea6e8b5816e0f 100644 (file)
--- a/drivers/net/sky2.c
+++ b/drivers/net/sky2.c
@@ -2093,6 +2093,7 @@ static int sky2_poll(struct net_device *dev0, int *budget)
        int work_done = 0;
        u32 status = sky2_read32(hw, B0_Y2_SP_EISR);
 
+ restart_poll:
        if (unlikely(status & ~Y2_IS_STAT_BMU)) {
                if (status & Y2_IS_HW_ERR)
                        sky2_hw_intr(hw);
@@ -2123,7 +2124,7 @@ static int sky2_poll(struct net_device *dev0, int *budget)
        }
 
        if (status & Y2_IS_STAT_BMU) {
-               work_done = sky2_status_intr(hw, work_limit);
+               work_done += sky2_status_intr(hw, work_limit - work_done);
                *budget -= work_done;
                dev0->quota -= work_done;
 
@@ -2133,9 +2134,22 @@ static int sky2_poll(struct net_device *dev0, int *budget)
                sky2_write32(hw, STAT_CTRL, SC_STAT_CLR_IRQ);
        }
 
-       netif_rx_complete(dev0);
+       local_irq_disable();
+       __netif_rx_complete(dev0);
 
        status = sky2_read32(hw, B0_Y2_SP_LISR);
+
+       if (unlikely(status)) {
+               /* More work pending, try and keep going */
+               if (__netif_rx_schedule_prep(dev0)) {
+                       __netif_rx_reschedule(dev0, work_done);
+                       status = sky2_read32(hw, B0_Y2_SP_EISR);
+                       local_irq_enable();
+                       goto restart_poll;
+               }
+       }
+
+       local_irq_enable();
        return 0;
 }
 
@@ -2153,8 +2167,6 @@ static irqreturn_t sky2_intr(int irq, void *dev_id, struct pt_regs *regs)
        prefetch(&hw->st_le[hw->st_idx]);
        if (likely(__netif_rx_schedule_prep(dev0)))
                __netif_rx_schedule(dev0);
-       else
-               printk(KERN_DEBUG PFX "irq race detected\n");
 
        return IRQ_HANDLED;
 }

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 40ccf8cc4239361b18925d46c070c8f7a8dbd9ae..01db7b88a2b1c626f668085364ca6181ba9ca641 100644 (file)
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -829,19 +829,21 @@ static inline void netif_rx_schedule(struct net_device *dev)
                __netif_rx_schedule(dev);
 }
 
-/* Try to reschedule poll. Called by dev->poll() after netif_rx_complete().
- * Do not inline this?
- */
+
+static inline void  __netif_rx_reschedule(struct net_device *dev, int undo)
+{
+       dev->quota += undo;
+       list_add_tail(&dev->poll_list, &__get_cpu_var(softnet_data).poll_list);
+       __raise_softirq_irqoff(NET_RX_SOFTIRQ);
+}
+
+/* Try to reschedule poll. Called by dev->poll() after netif_rx_complete(). */
 static inline int netif_rx_reschedule(struct net_device *dev, int undo)
 {
        if (netif_rx_schedule_prep(dev)) {
                unsigned long flags;
-
-               dev->quota += undo;
-
                local_irq_save(flags);
-               list_add_tail(&dev->poll_list, &__get_cpu_var(softnet_data).poll_list);
-               __raise_softirq_irqoff(NET_RX_SOFTIRQ);
+               __netif_rx_reschedule(dev, undo);
                local_irq_restore(flags);
                return 1;
        }