[PATCH] sky2: poke coalescing timer to fix hang

Need to restart the interrupt coalescing timer after clearing the interrupt,
to avoid races with interrupt timer and processing.

Patch from Carl-Daniel Halfinger

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c
index cf7fd28d6776..629809433cb3 100644
--- a/drivers/net/sky2.c
+++ b/drivers/net/sky2.c
@@ -1895,6 +1895,17 @@ static int sky2_poll(struct net_device *dev0, int *budget)
 
         sky2_write32(hw, STAT_CTRL, SC_STAT_CLR_IRQ);
 
+        /*
+         * Kick the STAT_LEV_TIMER_CTRL timer.
+         * This fixes my hangs on Yukon-EC (0xb6) rev 1.
+         * The if clause is there to start the timer only if it has been
+         * configured correctly and not been disabled via ethtool.
+         */
+        if (sky2_read8(hw, STAT_LEV_TIMER_CTRL) == TIM_START) {
+                sky2_write8(hw, STAT_LEV_TIMER_CTRL, TIM_STOP);
+                sky2_write8(hw, STAT_LEV_TIMER_CTRL, TIM_START);
+        }
+
         hwidx = sky2_read16(hw, STAT_PUT_IDX);
         BUG_ON(hwidx >= STATUS_RING_SIZE);
         rmb();