From c96f90776325ceb9fcda278cba8bc85e287d8d15 Mon Sep 17 00:00:00 2001
From: "nagalakshmi.nandigama@lsi.com" <nagalakshmi.nandigama@lsi.com>
Date: Thu, 1 Dec 2011 07:52:56 +0530
Subject: [PATCH 036/130] SCSI: mpt2sas: Release spinlock for the raid device
 list before blocking it

commit 30c43282f3d347f47f9e05199d2b14f56f3f2837 upstream.

Added code to release the spinlock that is used to protect the
raid device list before calling a function that can block. The
blocking was causing a reschedule, and subsequently it is tried
to acquire the same lock, resulting in a panic (NMI Watchdog
detecting a CPU lockup).

Signed-off-by: Nagalakshmi Nandigama <nagalakshmi.nandigama@lsi.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 drivers/scsi/mpt2sas/mpt2sas_scsih.c |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/mpt2sas/mpt2sas_scsih.c b/drivers/scsi/mpt2sas/mpt2sas_scsih.c
index d570573..3a4f666 100644
--- a/drivers/scsi/mpt2sas/mpt2sas_scsih.c
+++ b/drivers/scsi/mpt2sas/mpt2sas_scsih.c
@@ -6714,6 +6714,7 @@ _scsih_mark_responding_raid_device(struct MPT2SAS_ADAPTER *ioc, u64 wwid,
 			} else
 				sas_target_priv_data = NULL;
 			raid_device->responding = 1;
+			spin_unlock_irqrestore(&ioc->raid_device_lock, flags);
 			starget_printk(KERN_INFO, raid_device->starget,
 			    "handle(0x%04x), wwid(0x%016llx)\n", handle,
 			    (unsigned long long)raid_device->wwid);
@@ -6724,16 +6725,16 @@ _scsih_mark_responding_raid_device(struct MPT2SAS_ADAPTER *ioc, u64 wwid,
 			 */
 			_scsih_init_warpdrive_properties(ioc, raid_device);
 			if (raid_device->handle == handle)
-				goto out;
+				return;
 			printk(KERN_INFO "\thandle changed from(0x%04x)!!!\n",
 			    raid_device->handle);
 			raid_device->handle = handle;
 			if (sas_target_priv_data)
 				sas_target_priv_data->handle = handle;
-			goto out;
+			return;
 		}
 	}
- out:
+
 	spin_unlock_irqrestore(&ioc->raid_device_lock, flags);
 }
 
-- 
1.7.7.4

