sky2: restore workarounds for lost interrupts

Backport of commit c59697e0

This patch restores a couple of workarounds from 2.6.16:
 * restart transmit moderation timer in case it expires during IRQ routine
 * default to having 10 HZ watchdog timer.
At this point it more important not to hang than to worry about the
power cost.
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/net/sky2.c

@@ -96,7 +96,7 @@ 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 = 0;
+static int idle_timeout = 100;
 module_param(idle_timeout, int, 0);
 MODULE_PARM_DESC(idle_timeout, "Watchdog timer for lost interrupts (ms)");
 
@@ -2442,6 +2442,13 @@ static int sky2_poll(struct net_device *dev0, int *budget)
 
 	work_done = sky2_status_intr(hw, work_limit);
 	if (work_done < work_limit) {
+		/* Bug/Errata workaround?
+		 * Need to kick the TX irq moderation timer.
+		 */
+		if (sky2_read8(hw, STAT_TX_TIMER_CTRL) == TIM_START) {
+			sky2_write8(hw, STAT_TX_TIMER_CTRL, TIM_STOP);
+			sky2_write8(hw, STAT_TX_TIMER_CTRL, TIM_START);
+		}
 		netif_rx_complete(dev0);
 
 		/* end of interrupt, re-enables also acts as I/O synchronization */