S2io: Check for device state before handling traffic

- Added check to return from the traffic handling function, if the card status
  is DOWN.
- Implemented Jeff's comments on incorrect return value in s2io_poll function.

Signed-off-by: Sivakumar Subramani <sivakumar.subramani@neterion.com>
Signed-off-by: Santosh Rastapur <santosh.rastapur@neterion.com>
Signed-off-by: Ramkrishna Vepa <ram.vepa@neterion.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

2 files changed, 46 insertions, 22 deletions

diff --git a/drivers/net/s2io.c b/drivers/net/s2io.c
index 2ee2a2b4b272..d167bc0ae951 100644
--- a/drivers/net/s2io.c
+++ b/drivers/net/s2io.c
@@ -130,6 +130,11 @@ static inline int rx_buffer_level(struct s2io_nic * sp, int rxb_size, int ring)
         return 0;
 }
 
+static inline int is_s2io_card_up(const struct s2io_nic * sp)
+{
+        return test_bit(__S2IO_STATE_CARD_UP, &sp->state);
+}
+
 /* Ethtool related variables and Macros. */
 static char s2io_gstrings[][ETH_GSTRING_LEN] = {
         "Register test\t(offline)",
@@ -2711,6 +2716,12 @@ static int s2io_poll(struct napi_struct *napi, int budget)
         int i;
 
         atomic_inc(&nic->isr_cnt);
+
+        if (!is_s2io_card_up(nic)) {
+                atomic_dec(&nic->isr_cnt);
+                return 0;
+        }
+
         mac_control = &nic->mac_control;
         config = &nic->config;
 
@@ -2837,12 +2848,6 @@ static void rx_intr_handler(struct ring_info *ring_data)
         struct RxD3* rxdp3;
 
         spin_lock(&nic->rx_lock);
-        if (atomic_read(&nic->card_state) == CARD_DOWN) {
-                DBG_PRINT(INTR_DBG, "%s: %s going down for reset\n",
-                          __FUNCTION__, dev->name);
-                spin_unlock(&nic->rx_lock);
-                return;
-        }
 
         get_info = ring_data->rx_curr_get_info;
         get_block = get_info.block_index;
@@ -3990,7 +3995,7 @@ static int s2io_xmit(struct sk_buff *skb, struct net_device *dev)
 }
 
         spin_lock_irqsave(&sp->tx_lock, flags);
-        if (atomic_read(&sp->card_state) == CARD_DOWN) {
+        if (!is_s2io_card_up(sp)) {
                 DBG_PRINT(TX_DBG, "%s: Card going down for reset\n",
                           dev->name);
                 spin_unlock_irqrestore(&sp->tx_lock, flags);
@@ -4184,6 +4189,11 @@ static irqreturn_t s2io_msix_ring_handle(int irq, void *dev_id)
 
         atomic_inc(&sp->isr_cnt);
 
+        if (!is_s2io_card_up(sp)) {
+                atomic_dec(&sp->isr_cnt);
+                return IRQ_HANDLED;
+        }
+
         rx_intr_handler(ring);
         s2io_chk_rx_buffers(sp, ring->ring_no);
 
@@ -4197,6 +4207,12 @@ static irqreturn_t s2io_msix_fifo_handle(int irq, void *dev_id)
         struct s2io_nic *sp = fifo->nic;
 
         atomic_inc(&sp->isr_cnt);
+
+        if (!is_s2io_card_up(sp)) {
+                atomic_dec(&sp->isr_cnt);
+                return IRQ_HANDLED;
+        }
+
         tx_intr_handler(fifo);
         atomic_dec(&sp->isr_cnt);
         return IRQ_HANDLED;
@@ -4305,7 +4321,7 @@ static void s2io_handle_errors(void * dev_id)
         struct swStat *sw_stat = &sp->mac_control.stats_info->sw_stat;
         struct xpakStat *stats = &sp->mac_control.stats_info->xpak_stat;
 
-        if (unlikely(atomic_read(&sp->card_state) == CARD_DOWN))
+        if (!is_s2io_card_up(sp))
                 return;
 
         if (pci_channel_offline(sp->pdev))
@@ -4576,6 +4592,12 @@ static irqreturn_t s2io_isr(int irq, void *dev_id)
                 return IRQ_NONE;
 
         atomic_inc(&sp->isr_cnt);
+
+        if (!is_s2io_card_up(sp)) {
+                atomic_dec(&sp->isr_cnt);
+                return IRQ_NONE;
+        }
+
         mac_control = &sp->mac_control;
         config = &sp->config;
 
@@ -4664,7 +4686,7 @@ static void s2io_updt_stats(struct s2io_nic *sp)
         u64 val64;
         int cnt = 0;
 
-        if (atomic_read(&sp->card_state) == CARD_UP) {
+        if (is_s2io_card_up(sp)) {
                 /* Apprx 30us on a 133 MHz bus */
                 val64 = SET_UPDT_CLICKS(10) |
                         STAT_CFG_ONE_SHOT_EN | STAT_CFG_STAT_EN;
@@ -6460,7 +6482,7 @@ static void s2io_set_link(struct work_struct *work)
         if (!netif_running(dev))
                 goto out_unlock;
 
-        if (test_and_set_bit(0, &(nic->link_state))) {
+        if (test_and_set_bit(__S2IO_STATE_LINK_TASK, &(nic->state))) {
                 /* The card is being reset, no point doing anything */
                 goto out_unlock;
         }
@@ -6516,7 +6538,7 @@ static void s2io_set_link(struct work_struct *work)
                 writeq(val64, &bar0->adapter_control);
                 s2io_link(nic, LINK_DOWN);
         }
-        clear_bit(0, &(nic->link_state));
+        clear_bit(__S2IO_STATE_LINK_TASK, &(nic->state));
 
 out_unlock:
         rtnl_unlock();
@@ -6825,10 +6847,10 @@ static void do_s2io_card_down(struct s2io_nic * sp, int do_io)
 
         del_timer_sync(&sp->alarm_timer);
         /* If s2io_set_link task is executing, wait till it completes. */
-        while (test_and_set_bit(0, &(sp->link_state))) {
+        while (test_and_set_bit(__S2IO_STATE_LINK_TASK, &(sp->state))) {
                 msleep(50);
         }
-        atomic_set(&sp->card_state, CARD_DOWN);
+        clear_bit(__S2IO_STATE_CARD_UP, &sp->state);
 
         /* disable Tx and Rx traffic on the NIC */
         if (do_io)
@@ -6879,7 +6901,7 @@ static void do_s2io_card_down(struct s2io_nic * sp, int do_io)
         free_rx_buffers(sp);
         spin_unlock_irqrestore(&sp->rx_lock, flags);
 
-        clear_bit(0, &(sp->link_state));
+        clear_bit(__S2IO_STATE_LINK_TASK, &(sp->state));
 }
 
 static void s2io_card_down(struct s2io_nic * sp)
@@ -6972,8 +6994,7 @@ static int s2io_card_up(struct s2io_nic * sp)
                 en_dis_able_nic_intrs(sp, interruptible, ENABLE_INTRS);
         }
 
-
-        atomic_set(&sp->card_state, CARD_UP);
+        set_bit(__S2IO_STATE_CARD_UP, &sp->state);
         return 0;
 }
 
@@ -7701,9 +7722,8 @@ s2io_init_nic(struct pci_dev *pdev, const struct pci_device_id *pre)
          * Initialize the tasklet status and link state flags
          * and the card state parameter
          */
-        atomic_set(&(sp->card_state), 0);
         sp->tasklet_status = 0;
-        sp->link_state = 0;
+        sp->state = 0;
 
         /* Initialize spinlocks */
         spin_lock_init(&sp->tx_lock);
diff --git a/drivers/net/s2io.h b/drivers/net/s2io.h
index c01abc1d89af..33e812ea7d18 100644
--- a/drivers/net/s2io.h
+++ b/drivers/net/s2io.h
@@ -802,6 +802,13 @@ struct lro {
         u8              saw_ts;
 };
 
+/* These flags represent the devices temporary state */
+enum s2io_device_state_t
+{
+        __S2IO_STATE_LINK_TASK=0,
+        __S2IO_STATE_CARD_UP
+};
+
 /* Structure representing one instance of the NIC */
 struct s2io_nic {
         int rxd_mode;
@@ -880,10 +887,6 @@ struct s2io_nic {
 
         int task_flag;
         unsigned long long start_time;
-#define CARD_DOWN 1
-#define CARD_UP 2
-        atomic_t card_state;
-        volatile unsigned long link_state;
         struct vlan_group *vlgrp;
 #define MSIX_FLG                0xA5
         struct msix_entry *entries;
@@ -906,6 +909,7 @@ struct s2io_nic {
         unsigned long   sending_both;
         u8              lro;
         u16             lro_max_aggr_per_sess;
+        volatile unsigned long state;
         spinlock_t      rx_lock;
         atomic_t        isr_cnt;
         u64             general_int_mask;