sky2: only bring up watchdog if link is active

This fixes the extra timer overhead that people were whining about
as a 2.6.23 regression.

Running the watchdog timer all the time is unneeded. Change it
to run only if link is up, and reduce frequency to save power.

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

diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c
index 33ba3486389edb68b3c694afe6cc1fda206f0dea..00c5f056ef7e57974f621ea04678b9213fe6b6f2 100644 (file)
--- a/drivers/net/sky2.c
+++ b/drivers/net/sky2.c
@@ -99,10 +99,6 @@ static int disable_msi = 0;
 module_param(disable_msi, int, 0);
 MODULE_PARM_DESC(disable_msi, "Disable Message Signaled Interrupt (MSI)");
 
-static int idle_timeout = 100;
-module_param(idle_timeout, int, 0);
-MODULE_PARM_DESC(idle_timeout, "Watchdog timer for lost interrupts (ms)");
-
 static const struct pci_device_id sky2_id_table[] = {
        { PCI_DEVICE(PCI_VENDOR_ID_SYSKONNECT, 0x9000) }, /* SK-9Sxx */
        { PCI_DEVICE(PCI_VENDOR_ID_SYSKONNECT, 0x9E00) }, /* SK-9Exx */
@@ -1624,6 +1620,9 @@ static int sky2_down(struct net_device *dev)
        if (netif_msg_ifdown(sky2))
                printk(KERN_INFO PFX "%s: disabling interface\n", dev->name);
 
+       if (netif_carrier_ok(dev) && --hw->active == 0)
+               del_timer(&hw->watchdog_timer);
+
        /* Stop more packets from being queued */
        netif_stop_queue(dev);
 
@@ -1744,6 +1743,10 @@ static void sky2_link_up(struct sky2_port *sky2)
 
        netif_carrier_on(sky2->netdev);
 
+       if (hw->active++ == 0)
+               mod_timer(&hw->watchdog_timer, jiffies + 1);
+
+
        /* Turn on link LED */
        sky2_write8(hw, SK_REG(port, LNK_LED_REG),
                    LINKLED_ON | LINKLED_BLINK_OFF | LINKLED_LINKSYNC_OFF);
@@ -1795,6 +1798,11 @@ static void sky2_link_down(struct sky2_port *sky2)
 
        netif_carrier_off(sky2->netdev);
 
+       /* Stop watchdog if both ports are not active */
+       if (--hw->active == 0)
+               del_timer(&hw->watchdog_timer);
+
+
        /* Turn on link LED */
        sky2_write8(hw, SK_REG(port, LNK_LED_REG), LINKLED_OFF);
 
@@ -2426,25 +2434,20 @@ static void sky2_le_error(struct sky2_hw *hw, unsigned port,
        sky2_write32(hw, Q_ADDR(q, Q_CSR), BMU_CLR_IRQ_CHK);
 }
 
-/* If idle then force a fake soft NAPI poll once a second
- * to work around cases where sharing an edge triggered interrupt.
- */
-static inline void sky2_idle_start(struct sky2_hw *hw)
-{
-       if (idle_timeout > 0)
-               mod_timer(&hw->idle_timer,
-                         jiffies + msecs_to_jiffies(idle_timeout));
-}
-
-static void sky2_idle(unsigned long arg)
+/* Check for lost IRQ once a second */
+static void sky2_watchdog(unsigned long arg)
 {
        struct sky2_hw *hw = (struct sky2_hw *) arg;
-       struct net_device *dev = hw->dev[0];
 
-       if (__netif_rx_schedule_prep(dev))
-               __netif_rx_schedule(dev);
+       if (sky2_read32(hw, B0_ISRC)) {
+               struct net_device *dev = hw->dev[0];
+
+               if (__netif_rx_schedule_prep(dev))
+                       __netif_rx_schedule(dev);
+       }
 
-       mod_timer(&hw->idle_timer, jiffies + msecs_to_jiffies(idle_timeout));
+       if (hw->active > 0)
+               mod_timer(&hw->watchdog_timer, round_jiffies(jiffies + HZ));
 }
 
 /* Hardware/software error handling */
@@ -2732,8 +2735,6 @@ static void sky2_restart(struct work_struct *work)
        struct net_device *dev;
        int i, err;
 
-       del_timer_sync(&hw->idle_timer);
-
        rtnl_lock();
        sky2_write32(hw, B0_IMSK, 0);
        sky2_read32(hw, B0_IMSK);
@@ -2762,8 +2763,6 @@ static void sky2_restart(struct work_struct *work)
                }
        }
 
-       sky2_idle_start(hw);
-
        rtnl_unlock();
 }
 
@@ -4030,11 +4029,9 @@ static int __devinit sky2_probe(struct pci_dev *pdev,
                        sky2_show_addr(dev1);
        }
 
-       setup_timer(&hw->idle_timer, sky2_idle, (unsigned long) hw);
+       setup_timer(&hw->watchdog_timer, sky2_watchdog, (unsigned long) hw);
        INIT_WORK(&hw->restart_work, sky2_restart);
 
-       sky2_idle_start(hw);
-
        pci_set_drvdata(pdev, hw);
 
        return 0;
@@ -4069,7 +4066,7 @@ static void __devexit sky2_remove(struct pci_dev *pdev)
        if (!hw)
                return;
 
-       del_timer_sync(&hw->idle_timer);
+       del_timer_sync(&hw->watchdog_timer);
 
        flush_scheduled_work();
 
@@ -4113,7 +4110,6 @@ static int sky2_suspend(struct pci_dev *pdev, pm_message_t state)
        if (!hw)
                return 0;
 
-       del_timer_sync(&hw->idle_timer);
        netif_poll_disable(hw->dev[0]);
 
        for (i = 0; i < hw->ports; i++) {
@@ -4179,7 +4175,7 @@ static int sky2_resume(struct pci_dev *pdev)
        }
 
        netif_poll_enable(hw->dev[0]);
-       sky2_idle_start(hw);
+
        return 0;
 out:
        dev_err(&pdev->dev, "resume failed (%d)\n", err);
@@ -4196,7 +4192,6 @@ static void sky2_shutdown(struct pci_dev *pdev)
        if (!hw)
                return;
 
-       del_timer_sync(&hw->idle_timer);
        netif_poll_disable(hw->dev[0]);
 
        for (i = 0; i < hw->ports; i++) {

diff --git a/drivers/net/sky2.h b/drivers/net/sky2.h
index dce4d276d4435e685232c7073ae98d26b9e1f818..72e12b7cfa40e27dd5af5e25e9294b416feef325 100644 (file)
--- a/drivers/net/sky2.h
+++ b/drivers/net/sky2.h
@@ -2045,12 +2045,13 @@ struct sky2_hw {
        u8                   chip_rev;
        u8                   pmd_type;
        u8                   ports;
+       u8                   active;
 
        struct sky2_status_le *st_le;
        u32                  st_idx;
        dma_addr_t           st_dma;
 
-       struct timer_list    idle_timer;
+       struct timer_list    watchdog_timer;
        struct work_struct   restart_work;
        int                  msi;
        wait_queue_head_t    msi_wait;