qla3xxx: bugfix tx reset after stress conditions.

To Reproduce the Problem:
To reproduce this panic consistently, we run an intensive network
application like 'netperf' and then switch to a different console.
After waiting for a couple of seconds, you will see a tx reset has occured.

Reason:
We enable interrupts even if we were not running.

Solution:
Now we will enable interrupts only after we are ready to give up the poll
routine.

Signed-off-by: Ron Mercer <ron.mercer@qlogic.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 41 insertions, 28 deletions

diff --git a/drivers/net/qla3xxx.c b/drivers/net/qla3xxx.c
index 7a2f01a22cbf..5bf446f7be15 100755
--- a/drivers/net/qla3xxx.c
+++ b/drivers/net/qla3xxx.c
@@ -1921,10 +1921,11 @@ static int ql_tx_rx_clean(struct ql3_adapter *qdev,
         struct net_rsp_iocb *net_rsp;
         struct net_device *ndev = qdev->ndev;
         unsigned long hw_flags;
+        int work_done = 0;
 
         /* While there are entries in the completion queue. */
         while ((cpu_to_le32(*(qdev->prsp_producer_index)) !=
-                qdev->rsp_consumer_index) && (*rx_cleaned < work_to_do)) {
+                qdev->rsp_consumer_index) && (work_done < work_to_do)) {
 
                 net_rsp = qdev->rsp_current;
                 switch (net_rsp->opcode) {
@@ -1975,37 +1976,41 @@ static int ql_tx_rx_clean(struct ql3_adapter *qdev,
                 } else {
                         qdev->rsp_current++;
                 }
+
+                work_done = *tx_cleaned + *rx_cleaned;
         }
 
-        spin_lock_irqsave(&qdev->hw_lock, hw_flags);
+        if(work_done) {
+                spin_lock_irqsave(&qdev->hw_lock, hw_flags);
 
-        ql_update_lrg_bufq_prod_index(qdev);
+                ql_update_lrg_bufq_prod_index(qdev);
 
-        if (qdev->small_buf_release_cnt >= 16) {
-                while (qdev->small_buf_release_cnt >= 16) {
-                        qdev->small_buf_q_producer_index++;
+                if (qdev->small_buf_release_cnt >= 16) {
+                        while (qdev->small_buf_release_cnt >= 16) {
+                                qdev->small_buf_q_producer_index++;
 
-                        if (qdev->small_buf_q_producer_index ==
-                            NUM_SBUFQ_ENTRIES)
-                                qdev->small_buf_q_producer_index = 0;
-                        qdev->small_buf_release_cnt -= 8;
-                }
+                                if (qdev->small_buf_q_producer_index ==
+                                    NUM_SBUFQ_ENTRIES)
+                                        qdev->small_buf_q_producer_index = 0;
+                                qdev->small_buf_release_cnt -= 8;
+                        }
 
-                ql_write_common_reg(qdev,
-                                    &port_regs->CommonRegs.
-                                    rxSmallQProducerIndex,
-                                    qdev->small_buf_q_producer_index);
-        }
+                        wmb();
+                        ql_write_common_reg(qdev,
+                                            &port_regs->CommonRegs.
+                                            rxSmallQProducerIndex,
+                                            qdev->small_buf_q_producer_index);
 
-        ql_write_common_reg(qdev,
-                            &port_regs->CommonRegs.rspQConsumerIndex,
-                            qdev->rsp_consumer_index);
-        spin_unlock_irqrestore(&qdev->hw_lock, hw_flags);
+                }
 
-        if (unlikely(netif_queue_stopped(qdev->ndev))) {
-                if (netif_queue_stopped(qdev->ndev) &&
-                    (atomic_read(&qdev->tx_count) > (NUM_REQ_Q_ENTRIES / 4)))
-                        netif_wake_queue(qdev->ndev);
+                spin_unlock_irqrestore(&qdev->hw_lock, hw_flags);
+
+                if (unlikely(netif_queue_stopped(qdev->ndev))) {
+                        if (netif_queue_stopped(qdev->ndev) &&
+                            (atomic_read(&qdev->tx_count) > 
+                             (NUM_REQ_Q_ENTRIES / 4)))
+                                netif_wake_queue(qdev->ndev);
+                }
         }
 
         return *tx_cleaned + *rx_cleaned;
@@ -2016,6 +2021,8 @@ static int ql_poll(struct net_device *ndev, int *budget)
         struct ql3_adapter *qdev = netdev_priv(ndev);
         int work_to_do = min(*budget, ndev->quota);
         int rx_cleaned = 0, tx_cleaned = 0;
+        unsigned long hw_flags;
+        struct ql3xxx_port_registers __iomem *port_regs = qdev->mem_map_registers;
 
         if (!netif_carrier_ok(ndev))
                 goto quit_polling;
@@ -2027,6 +2034,13 @@ static int ql_poll(struct net_device *ndev, int *budget)
         if ((!tx_cleaned && !rx_cleaned) || !netif_running(ndev)) {
 quit_polling:
                 netif_rx_complete(ndev);
+
+                spin_lock_irqsave(&qdev->hw_lock, hw_flags);
+                ql_write_common_reg(qdev,
+                                    &port_regs->CommonRegs.rspQConsumerIndex,
+                                    qdev->rsp_consumer_index);
+                spin_unlock_irqrestore(&qdev->hw_lock, hw_flags);
+
                 ql_enable_interrupts(qdev);
                 return 0;
         }
@@ -2079,11 +2093,10 @@ static irqreturn_t ql3xxx_isr(int irq, void *dev_id)
                 queue_delayed_work(qdev->workqueue, &qdev->reset_work, 0);
                 spin_unlock(&qdev->adapter_lock);
         } else if (value & ISP_IMR_DISABLE_CMPL_INT) {
-                ql_disable_interrupts(qdev);
-                if (likely(netif_rx_schedule_prep(ndev)))
+                if (likely(netif_rx_schedule_prep(ndev))) {
+                        ql_disable_interrupts(qdev);
                         __netif_rx_schedule(ndev);
-                else
-                        ql_enable_interrupts(qdev);
+                }
         } else {
                 return IRQ_NONE;
         }