e1000: Do not perform reset in reset_task if we are already down (#148)

Signed-off-by: Guohan Lu <lguohan@gmail.com>

patch/e1000-Do-not-perform-reset-in-reset_task-if-we-are-a.patch

@@ -0,0 +1,65 @@
+From 49ee3c2ab5234757bfb56a0b3a3cb422f427e3a3 Mon Sep 17 00:00:00 2001
+From: Alexander Duyck <alexander.h.duyck@linux.intel.com>
+Date: Fri, 17 Apr 2020 09:35:31 -0700
+Subject: [PATCH] e1000: Do not perform reset in reset_task if we are already
+ down
+
+We are seeing a deadlock in e1000 down when NAPI is being disabled. Looking
+over the kernel function trace of the system it appears that the interface
+is being closed and then a reset is hitting which deadlocks the interface
+as the NAPI interface is already disabled.
+
+To prevent this from happening I am disabling the reset task when
+__E1000_DOWN is already set. In addition code has been added so that we set
+the __E1000_DOWN while holding the __E1000_RESET flag in e1000_close in
+order to guarantee that the reset task will not run after we have started
+the close call.
+
+Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
+Tested-by: Maxim Zhukov <mussitantesmortem@gmail.com>
+Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
+---
+ drivers/net/ethernet/intel/e1000/e1000_main.c | 18 ++++++++++++++----
+ 1 file changed, 14 insertions(+), 4 deletions(-)
+
+diff --git a/drivers/net/ethernet/intel/e1000/e1000_main.c b/drivers/net/ethernet/intel/e1000/e1000_main.c
+index 05bc6e216bca..d9fa4600f745 100644
+--- a/drivers/net/ethernet/intel/e1000/e1000_main.c
++++ b/drivers/net/ethernet/intel/e1000/e1000_main.c
+@@ -542,8 +542,13 @@ void e1000_reinit_locked(struct e1000_adapter *adapter)
+ 	WARN_ON(in_interrupt());
+ 	while (test_and_set_bit(__E1000_RESETTING, &adapter->flags))
+ 		msleep(1);
+-	e1000_down(adapter);
+-	e1000_up(adapter);
++
++	/* only run the task if not already down */
++	if (!test_bit(__E1000_DOWN, &adapter->flags)) {
++		e1000_down(adapter);
++		e1000_up(adapter);
++	}
++
+ 	clear_bit(__E1000_RESETTING, &adapter->flags);
+ }
+
+@@ -1433,10 +1438,15 @@ int e1000_close(struct net_device *netdev)
+ 	struct e1000_hw *hw = &adapter->hw;
+ 	int count = E1000_CHECK_RESET_COUNT;
+
+-	while (test_bit(__E1000_RESETTING, &adapter->flags) && count--)
++	while (test_and_set_bit(__E1000_RESETTING, &adapter->flags) && count--)
+ 		usleep_range(10000, 20000);
+
+-	WARN_ON(test_bit(__E1000_RESETTING, &adapter->flags));
++	WARN_ON(count < 0);
++
++	/* signal that we're down so that the reset task will no longer run */
++	set_bit(__E1000_DOWN, &adapter->flags);
++	clear_bit(__E1000_RESETTING, &adapter->flags);
++
+ 	e1000_down(adapter);
+ 	e1000_power_down_phy(adapter);
+ 	e1000_free_irq(adapter);
+-- 
+2.17.1
+

patch/series

@@ -30,6 +30,7 @@ driver-support-optoe-EOF_fix.patch
 driver-support-optoe-chunk-offset-fix.patch
 driver-support-optoe-QSFP_DD.patch
 driver-net-tg3-add-param-short-preamble-and-reset.patch
+e1000-Do-not-perform-reset-in-reset_task-if-we-are-a.patch
 # (Marvel)
 # 0042-Marvell-a385-Micron-4G-flash-support.patch
 # 0042-armhf-additional-configs.patch