From: Raghava Aditya Renukunta <RaghavaAditya.Renukunta@microsemi.com>
Date: Tue, 26 Dec 2017 20:34:44 -0800
Subject: scsi: aacraid: Block concurrent hotplug event handling
Patch-mainline: v4.16-rc1
Git-commit: 3395614e48e26c6b05f87662ef354bca38999d2a
References: FATE#325927

Currently driver will attempt to process hotplug events concurrently based
on the FW interrupt.

Protect safw update function with a scan mutex.

Signed-off-by: Raghava Aditya Renukunta <RaghavaAditya.Renukunta@microsemi.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Johannes Thumshirn <jthumshirn@suse.de>
---
 drivers/scsi/aacraid/aacraid.h |    1 +
 drivers/scsi/aacraid/commsup.c |    2 ++
 drivers/scsi/aacraid/linit.c   |    1 +
 3 files changed, 4 insertions(+)

--- a/drivers/scsi/aacraid/aacraid.h
+++ b/drivers/scsi/aacraid/aacraid.h
@@ -1565,6 +1565,7 @@ struct aac_dev
 	spinlock_t		fib_lock;
 
 	struct mutex		ioctl_mutex;
+	struct mutex		scan_mutex;
 	struct aac_queue_block *queues;
 	/*
 	 *	The user API will use an IOCTL to register itself to receive
--- a/drivers/scsi/aacraid/commsup.c
+++ b/drivers/scsi/aacraid/commsup.c
@@ -1968,7 +1968,9 @@ static void aac_handle_sa_aif(struct aac
 	case SA_AIF_LDEV_CHANGE:
 	case SA_AIF_BPCFG_CHANGE:
 
+		mutex_lock(&dev->scan_mutex);
 		aac_update_safw_host_devices(dev, AAC_RESCAN);
+		mutex_unlock(&dev->scan_mutex);
 		break;
 
 	case SA_AIF_BPSTAT_CHANGE:
--- a/drivers/scsi/aacraid/linit.c
+++ b/drivers/scsi/aacraid/linit.c
@@ -1686,6 +1686,7 @@ static int aac_probe_one(struct pci_dev
 	spin_lock_init(&aac->fib_lock);
 
 	mutex_init(&aac->ioctl_mutex);
+	mutex_init(&aac->scan_mutex);
 	/*
 	 *	Map in the registers from the adapter.
 	 */