1 files changed, 57 insertions, 45 deletions

diff --git a/drivers/net/r8169.c b/drivers/net/r8169.c
index 7fa88d2b4c99..e94316b7868b 100644
--- a/drivers/net/r8169.c
+++ b/drivers/net/r8169.c
@@ -3561,54 +3561,64 @@ static irqreturn_t rtl8169_interrupt(int irq, void *dev_instance)
         int handled = 0;
         int status;
 
+        /* loop handling interrupts until we have no new ones or
+         * we hit a invalid/hotplug case.
+         */
         status = RTL_R16(IntrStatus);
+        while (status && status != 0xffff) {
+                handled = 1;
 
-        /* hotplug/major error/no more work/shared irq */
-        if ((status == 0xffff) || !status)
-                goto out;
-
-        handled = 1;
+                /* Handle all of the error cases first. These will reset
+                 * the chip, so just exit the loop.
+                 */
+                if (unlikely(!netif_running(dev))) {
+                        rtl8169_asic_down(ioaddr);
+                        break;
+                }
 
-        if (unlikely(!netif_running(dev))) {
-                rtl8169_asic_down(ioaddr);
-                goto out;
-        }
+                /* Work around for rx fifo overflow */
+                if (unlikely(status & RxFIFOOver) &&
+                (tp->mac_version == RTL_GIGA_MAC_VER_11)) {
+                        netif_stop_queue(dev);
+                        rtl8169_tx_timeout(dev);
+                        break;
+                }
 
-        status &= tp->intr_mask;
-        RTL_W16(IntrStatus,
-                (status & RxFIFOOver) ? (status | RxOverflow) : status);
+                if (unlikely(status & SYSErr)) {
+                        rtl8169_pcierr_interrupt(dev);
+                        break;
+                }
 
-        if (!(status & tp->intr_event))
-                goto out;
+                if (status & LinkChg)
+                        rtl8169_check_link_status(dev, tp, ioaddr);
 
-        /* Work around for rx fifo overflow */
-        if (unlikely(status & RxFIFOOver) &&
-            (tp->mac_version == RTL_GIGA_MAC_VER_11)) {
-                netif_stop_queue(dev);
-                rtl8169_tx_timeout(dev);
-                goto out;
-        }
+                /* We need to see the lastest version of tp->intr_mask to
+                 * avoid ignoring an MSI interrupt and having to wait for
+                 * another event which may never come.
+                 */
+                smp_rmb();
+                if (status & tp->intr_mask & tp->napi_event) {
+                        RTL_W16(IntrMask, tp->intr_event & ~tp->napi_event);
+                        tp->intr_mask = ~tp->napi_event;
+
+                        if (likely(napi_schedule_prep(&tp->napi)))
+                                __napi_schedule(&tp->napi);
+                        else if (netif_msg_intr(tp)) {
+                                printk(KERN_INFO "%s: interrupt %04x in poll\n",
+                                dev->name, status);
+                        }
+                }
 
-        if (unlikely(status & SYSErr)) {
-                rtl8169_pcierr_interrupt(dev);
-                goto out;
+                /* We only get a new MSI interrupt when all active irq
+                 * sources on the chip have been acknowledged. So, ack
+                 * everything we've seen and check if new sources have become
+                 * active to avoid blocking all interrupts from the chip.
+                 */
+                RTL_W16(IntrStatus,
+                        (status & RxFIFOOver) ? (status | RxOverflow) : status);
+                status = RTL_R16(IntrStatus);
         }
 
-        if (status & LinkChg)
-                rtl8169_check_link_status(dev, tp, ioaddr);
-
-        if (status & tp->napi_event) {
-                RTL_W16(IntrMask, tp->intr_event & ~tp->napi_event);
-                tp->intr_mask = ~tp->napi_event;
-
-                if (likely(napi_schedule_prep(&tp->napi)))
-                        __napi_schedule(&tp->napi);
-                else if (netif_msg_intr(tp)) {
-                        printk(KERN_INFO "%s: interrupt %04x in poll\n",
-                               dev->name, status);
-                }
-        }
-out:
         return IRQ_RETVAL(handled);
 }
 
@@ -3624,13 +3634,15 @@ static int rtl8169_poll(struct napi_struct *napi, int budget)
 
         if (work_done < budget) {
                 napi_complete(napi);
-                tp->intr_mask = 0xffff;
-                /*
-                 * 20040426: the barrier is not strictly required but the
-                 * behavior of the irq handler could be less predictable
-                 * without it. Btw, the lack of flush for the posted pci
-                 * write is safe - FR
+
+                /* We need for force the visibility of tp->intr_mask
+                 * for other CPUs, as we can loose an MSI interrupt
+                 * and potentially wait for a retransmit timeout if we don't.
+                 * The posted write to IntrMask is safe, as it will
+                 * eventually make it to the chip and we won't loose anything
+                 * until it does.
                  */
+                tp->intr_mask = 0xffff;
                 smp_wmb();
                 RTL_W16(IntrMask, tp->intr_event);
         }