[PATCH 1/1] e1000: prevent oops when adapter is being closed and reset simultaneously

[yzhu1 <Yanjun.Zhu@windriver.com>]

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Hi, maintainers

This change is based on a similar change made to e1000e support in
commit bb9e44d0d0f4 ("e1000e: prevent oops when adapter is being closed
and reset simultaneously").  The same issue has also been observed
on the older e1000 cards.

Here, we have increased the RESET_COUNT value to 50 because there are too
many accesses to e1000 nic on stress tests to e1000 nic, it is not enough
to set RESET_COUT 25. Experimentation has shown that it is enough to set
RESET_COUNT 50.

Please help me to merge this patch. Thanks a lot.

Zhu Yanjun

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>From 54e9e48a9f878eb45f0cc6322415244d7a9f1598 Mon Sep 17 00:00:00 2001
From: yzhu1 <yanjun.zhu@windriver.com>
Date: Fri, 22 Nov 2013 15:46:48 +0800
Subject: [PATCH 1/1] e1000: prevent oops when adapter is being closed and
 reset simultaneously

This change is based on a similar change made to e1000e support in
commit bb9e44d0d0f4 ("e1000e: prevent oops when adapter is being closed
and reset simultaneously").  The same issue has also been observed
on the older e1000 cards.

Here, we have increased the RESET_COUNT value to 50 because there are too
many accesses to e1000 nic on stress tests to e1000 nic, it is not enough
to set RESET_COUT 25. Experimentation has shown that it is enough to set
RESET_COUNT 50.

Signed-off-by: yzhu1 <yanjun.zhu@windriver.com>
---
 drivers/net/ethernet/intel/e1000/e1000.h      |    5 +++++
 drivers/net/ethernet/intel/e1000/e1000_main.c |    9 +++++++++
 2 files changed, 14 insertions(+)

diff --git a/drivers/net/ethernet/intel/e1000/e1000.h b/drivers/net/ethernet/intel/e1000/e1000.h
index 58c1472..0af4a8e 100644
--- a/drivers/net/ethernet/intel/e1000/e1000.h
+++ b/drivers/net/ethernet/intel/e1000/e1000.h
@@ -83,6 +83,11 @@ struct e1000_adapter;
 
 #define E1000_MAX_INTR			10
 
+/*
+ * Count for polling __E1000_RESET condition every 10-20msec.
+ */
+#define E1000_CHECK_RESET_COUNT         50
+
 /* TX/RX descriptor defines */
 #define E1000_DEFAULT_TXD		256
 #define E1000_MAX_TXD			256
diff --git a/drivers/net/ethernet/intel/e1000/e1000_main.c b/drivers/net/ethernet/intel/e1000/e1000_main.c
index e386228..c0f5217 100644
--- a/drivers/net/ethernet/intel/e1000/e1000_main.c
+++ b/drivers/net/ethernet/intel/e1000/e1000_main.c
@@ -1440,6 +1440,10 @@ static int e1000_close(struct net_device *netdev)
 {
 	struct e1000_adapter *adapter = netdev_priv(netdev);
 	struct e1000_hw *hw = &adapter->hw;
+	int count = E1000_CHECK_RESET_COUNT;
+
+	while (test_bit(__E1000_RESETTING, &adapter->flags) && count--)
+		usleep_range(10000, 20000);
 
 	WARN_ON(test_bit(__E1000_RESETTING, &adapter->flags));
 	e1000_down(adapter);
@@ -4963,6 +4967,11 @@ static int __e1000_shutdown(struct pci_dev *pdev, bool *enable_wake)
 	netif_device_detach(netdev);
 
 	if (netif_running(netdev)) {
+		int count = E1000_CHECK_RESET_COUNT;
+
+		while (test_bit(__E1000_RESETTING, &adapter->flags) && count--)
+			usleep_range(10000, 20000);
+
 		WARN_ON(test_bit(__E1000_RESETTING, &adapter->flags));
 		e1000_down(adapter);
 	}
-- 
1.7.9.5