From: Chad Dupuis <cdupuis@redhat.com>
Date: Fri, 19 Nov 2010 18:25:30 -0500
Subject: [net] qlge: fix deadlock when interface is going down
Message-id: <20101119182530.6308.77393.sendpatchset@localhost.localdomain>
Patchwork-id: 29522
O-Subject: [RHEL 5.6 PATCH 3/5] qlge: Fix a deadlock when the interface is going
	down.
Bugzilla: 654420
RH-Acked-by: David S. Miller <davem@redhat.com>

Bugzilla
--------

Bug 654420 (https://bugzilla.redhat.com/show_bug.cgi?id=654420)

Upstream Status
---------------

net-2.6 commit id c5dadddb8c9d310bc263f671f19fe3ba90b329fe

Further rtnl locking fix still pending.

Description
-----------

>From 8b24aebe8c541a9e81190ec53caad23e98dc493b Mon Sep 17 00:00:00 2001
From: Jitendra Kalsaria <jitendra.kalsaria@qlogic.com>
Date: Wed, 13 Oct 2010 14:04:57 -0700
Subject: [PATCH 3/5] qlge: Fix a deadlock when the interface is going down.

	Currently qlge can deadlock when the interface is going
	down, and the mpi_port_cfg_work() is executing on another
	processor. It happens because unregister_netdev() holds
	the rtnl lock, and the mpi_port_cfg_work() also request
	this lock.

	Since unregister_netdev() may wait mpi_port_cfg_work(), who
	also request the holding lock, it can cause an deadlock,

	Signed-off-by: Jitendra Kalsaria <jitendra.kalsaria@qlogic.com>

>From 8b7d7e81ee5f5c4691c37ea4dca32af3cbb42caf Mon Sep 17 00:00:00 2001
From: Jitendra Kalsaria <jitendra.kalsaria@qlogic.com>
Date: Wed, 1 Dec 2010 13:51:57 -0800
Subject: [PATCH 1/1] qlge: During mtu change, rtnl_lock is called on error case
	in ql_change_rx_buffers(), which can cause deadlock.

	Signed-off-by: Jitendra Kalsaria <jitendra.kalsaria@qlogic.com>


diff --git a/drivers/net/qlge/qlge_main.c b/drivers/net/qlge/qlge_main.c
index d10de66..789f0a5 100644
--- a/drivers/net/qlge/qlge_main.c
+++ b/drivers/net/qlge/qlge_main.c
@@ -3661,12 +3661,8 @@ static void ql_enable_napi(struct ql_adapter *qdev)
 		netif_poll_enable(qdev->rx_ring[i].dummy_netdev);
 }
 
-static int ql_adapter_down(struct ql_adapter *qdev)
+static void ql_cancel_all_work_sync(struct ql_adapter *qdev)
 {
-	int i, status = 0;
-
-	ql_link_off(qdev);
-
 	/* Don't kill the reset worker thread if we
 	 * are in the process of recovery.
 	 */
@@ -3678,6 +3674,15 @@ static int ql_adapter_down(struct ql_adapter *qdev)
 	cancel_delayed_work_sync(&qdev->mpi_core_to_log);
 	cancel_delayed_work_sync(&qdev->mpi_port_cfg_work);
 	cancel_delayed_work_sync(&qdev->link_work);
+}
+
+static int ql_adapter_down(struct ql_adapter *qdev)
+{
+	int i, status = 0;
+
+	ql_link_off(qdev);
+	
+	ql_cancel_all_work_sync(qdev);
 
 	for (i = 0; i < qdev->tx_ring_count; i++)
 		del_timer_sync(&qdev->tx_ring[i].txq_clean_timer);
@@ -3942,10 +3947,8 @@ static int ql_change_rx_buffers(struct ql_adapter *qdev)
 error:
 	QPRINTK(qdev, IFUP, ALERT,
 		"Driver up/down cycle failed, closing device.\n");
-	rtnl_lock();
 	set_bit(QL_ADAPTER_UP, &qdev->flags);
 	dev_close(qdev->ndev);
-	rtnl_unlock();
 	return status;
 }
 
@@ -4626,6 +4629,7 @@ static void __devexit qlge_remove(struct pci_dev *pdev)
 	struct ql_adapter *qdev = netdev_priv(ndev);
 
 	del_timer_sync(&qdev->eeh_timer);
+	ql_cancel_all_work_sync(qdev);
 	unregister_netdev(ndev);
 	ql_deinit_napi(qdev);
 	ql_release_all(pdev);
@@ -4646,14 +4650,7 @@ static void ql_eeh_close(struct net_device *ndev)
 	/* Disabling the timer */
 	del_timer_sync(&qdev->eeh_timer);
 
-	if (test_bit(QL_ADAPTER_UP, &qdev->flags))
-		cancel_delayed_work_sync(&qdev->asic_reset_work);
-	cancel_delayed_work_sync(&qdev->mpi_reset_work);
-	cancel_delayed_work_sync(&qdev->mpi_work);
-	cancel_delayed_work_sync(&qdev->mpi_idc_work);
-	cancel_delayed_work_sync(&qdev->mpi_core_to_log);
-	cancel_delayed_work_sync(&qdev->mpi_port_cfg_work);
-	cancel_delayed_work_sync(&qdev->link_work);
+	ql_cancel_all_work_sync(qdev);
 
 	for (i = 0; i < qdev->tx_ring_count; i++)
 		del_timer_sync(&qdev->tx_ring[i].txq_clean_timer);