[PATCH] Fix kernel panic issue after removing igb driver

[marshall.shao@dell.com]

From: Marshall Shao <Marshall.Shao@dell.com>

This patch fixes a kernel panic issue after removing the igb driver 
from the usermode.

A delayed work will be schedule in igb_ptp_init(),

	if (adapter->ptp_flags & IGB_PTP_OVERFLOW_CHECK)
		INIT_DELAYED_WORK(&adapter->ptp_overflow_work,
				  igb_ptp_overflow_check);

If CONFIG_PTP_1588_CLOCK is not enabled, the delayed work cannot be
cancelled when igb_ptp_suspend is called.

Signed-off-by: Marshall Shao <Marshall.Shao@dell.com>
---
 drivers/net/ethernet/intel/igb/igb_ptp.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/intel/igb/igb_ptp.c b/drivers/net/ethernet/intel/igb/igb_ptp.c
index 405886ee5261..b21822ea1c7d 100644
--- a/drivers/net/ethernet/intel/igb/igb_ptp.c
+++ b/drivers/net/ethernet/intel/igb/igb_ptp.c
@@ -1435,12 +1435,12 @@ void igb_ptp_sdp_init(struct igb_adapter *adapter)
  */
 void igb_ptp_suspend(struct igb_adapter *adapter)
 {
-	if (!(adapter->ptp_flags & IGB_PTP_ENABLED))
-		return;
-
 	if (adapter->ptp_flags & IGB_PTP_OVERFLOW_CHECK)
 		cancel_delayed_work_sync(&adapter->ptp_overflow_work);
 
+	if (!(adapter->ptp_flags & IGB_PTP_ENABLED))
+		return;
+
 	cancel_work_sync(&adapter->ptp_tx_work);
 	if (adapter->ptp_tx_skb) {
 		dev_kfree_skb_any(adapter->ptp_tx_skb);
-- 
2.34.1