commit 282edcece39e08d02c22492d593e4b9b94a65dff
author stephen hemminger <shemminger@vyatta.com> Thu Nov 17 14:37:35 2011 +0000
committer David S. Miller <davem@davemloft.net> Thu Nov 17 21:43:57 2011 -0500
tree a0d0c9816a5ef76bc637a573e382379600016e09
parent 738a849c8eef4787a526d95763f985b8c1cb68e4

sky2: fix hang in napi_disable

If IRQ was never initialized, then calling napi_disable() would hang.
Add more bookkeeping to track whether IRQ was ever initialized.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/marvell/sky2.c

diff --git a/drivers/net/ethernet/marvell/sky2.c b/drivers/net/ethernet/marvell/sky2.c
index d996871..7803efa 100644
--- a/drivers/net/ethernet/marvell/sky2.c
+++ b/drivers/net/ethernet/marvell/sky2.c
@@ -1723,6 +1723,8 @@
 	if (err)
 		dev_err(&pdev->dev, "cannot assign irq %d\n", pdev->irq);
 	else {
+		hw->flags |= SKY2_HW_IRQ_SETUP;
+
 		napi_enable(&hw->napi);
 		sky2_write32(hw, B0_IMSK, Y2_IS_BASE);
 		sky2_read32(hw, B0_IMSK);
@@ -2120,6 +2122,7 @@
 
 		napi_disable(&hw->napi);
 		free_irq(hw->pdev->irq, hw);
+		hw->flags &= ~SKY2_HW_IRQ_SETUP;
 	} else {
 		u32 imask;
 
@@ -3423,12 +3426,13 @@
 {
 	int i;
 
-	sky2_read32(hw, B0_IMSK);
-	sky2_write32(hw, B0_IMSK, 0);
+	if (hw->flags & SKY2_HW_IRQ_SETUP) {
+		sky2_read32(hw, B0_IMSK);
+		sky2_write32(hw, B0_IMSK, 0);
 
-	if (hw->ports > 1 || netif_running(hw->dev[0]))
 		synchronize_irq(hw->pdev->irq);
-	napi_disable(&hw->napi);
+		napi_disable(&hw->napi);
+	}
 
 	for (i = 0; i < hw->ports; i++) {
 		struct net_device *dev = hw->dev[i];
@@ -3445,7 +3449,7 @@
 
 static void sky2_all_up(struct sky2_hw *hw)
 {
-	u32 imask = 0;
+	u32 imask = Y2_IS_BASE;
 	int i;
 
 	for (i = 0; i < hw->ports; i++) {
@@ -3461,8 +3465,7 @@
 		netif_wake_queue(dev);
 	}
 
-	if (imask || hw->ports > 1) {
-		imask |= Y2_IS_BASE;
+	if (hw->flags & SKY2_HW_IRQ_SETUP) {
 		sky2_write32(hw, B0_IMSK, imask);
 		sky2_read32(hw, B0_IMSK);
 		sky2_read32(hw, B0_Y2_SP_LISR);