[SCSI] mpt2sas: fix crash due to Watchdog is active while OS in standby mode

Fix oops ocurring at hibernation time.  This oops was due to the firmware fault
watchdog timer still running after we freed resources. To fix the issue we need
to terminate the watchdog timer at hibernation time.

Signed-off-by: Kashyap Desai <kashyap.desai@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

3 files changed, 64 insertions, 28 deletions

diff --git a/drivers/scsi/mpt2sas/mpt2sas_base.c b/drivers/scsi/mpt2sas/mpt2sas_base.c
index ed9965e4b96b..c29c4f9851b9 100644
--- a/drivers/scsi/mpt2sas/mpt2sas_base.c
+++ b/drivers/scsi/mpt2sas/mpt2sas_base.c
@@ -119,6 +119,64 @@ _base_fault_reset_work(struct work_struct *work)
         spin_unlock_irqrestore(&ioc->ioc_reset_in_progress_lock, flags);
 }
 
+/**
+ * mpt2sas_base_start_watchdog - start the fault_reset_work_q
+ * @ioc: pointer to scsi command object
+ * Context: sleep.
+ *
+ * Return nothing.
+ */
+void
+mpt2sas_base_start_watchdog(struct MPT2SAS_ADAPTER *ioc)
+{
+        unsigned long    flags;
+
+        if (ioc->fault_reset_work_q)
+                return;
+
+        /* initialize fault polling */
+        INIT_DELAYED_WORK(&ioc->fault_reset_work, _base_fault_reset_work);
+        snprintf(ioc->fault_reset_work_q_name,
+            sizeof(ioc->fault_reset_work_q_name), "poll_%d_status", ioc->id);
+        ioc->fault_reset_work_q =
+                create_singlethread_workqueue(ioc->fault_reset_work_q_name);
+        if (!ioc->fault_reset_work_q) {
+                printk(MPT2SAS_ERR_FMT "%s: failed (line=%d)\n",
+                    ioc->name, __func__, __LINE__);
+                        return;
+        }
+        spin_lock_irqsave(&ioc->ioc_reset_in_progress_lock, flags);
+        if (ioc->fault_reset_work_q)
+                queue_delayed_work(ioc->fault_reset_work_q,
+                    &ioc->fault_reset_work,
+                    msecs_to_jiffies(FAULT_POLLING_INTERVAL));
+        spin_unlock_irqrestore(&ioc->ioc_reset_in_progress_lock, flags);
+}
+
+/**
+ * mpt2sas_base_stop_watchdog - stop the fault_reset_work_q
+ * @ioc: pointer to scsi command object
+ * Context: sleep.
+ *
+ * Return nothing.
+ */
+void
+mpt2sas_base_stop_watchdog(struct MPT2SAS_ADAPTER *ioc)
+{
+        unsigned long    flags;
+        struct workqueue_struct *wq;
+
+        spin_lock_irqsave(&ioc->ioc_reset_in_progress_lock, flags);
+        wq = ioc->fault_reset_work_q;
+        ioc->fault_reset_work_q = NULL;
+        spin_unlock_irqrestore(&ioc->ioc_reset_in_progress_lock, flags);
+        if (wq) {
+                if (!cancel_delayed_work(&ioc->fault_reset_work))
+                        flush_workqueue(wq);
+                destroy_workqueue(wq);
+        }
+}
+
 #ifdef CONFIG_SCSI_MPT2SAS_LOGGING
 /**
  * _base_sas_ioc_info - verbose translation of the ioc status
@@ -3209,7 +3267,6 @@ int
 mpt2sas_base_attach(struct MPT2SAS_ADAPTER *ioc)
 {
         int r, i;
-        unsigned long    flags;
 
         dinitprintk(ioc, printk(MPT2SAS_DEBUG_FMT "%s\n", ioc->name,
             __func__));
@@ -3292,23 +3349,7 @@ mpt2sas_base_attach(struct MPT2SAS_ADAPTER *ioc)
         if (r)
                 goto out_free_resources;
 
-        /* initialize fault polling */
-        INIT_DELAYED_WORK(&ioc->fault_reset_work, _base_fault_reset_work);
-        snprintf(ioc->fault_reset_work_q_name,
-            sizeof(ioc->fault_reset_work_q_name), "poll_%d_status", ioc->id);
-        ioc->fault_reset_work_q =
-                create_singlethread_workqueue(ioc->fault_reset_work_q_name);
-        if (!ioc->fault_reset_work_q) {
-                printk(MPT2SAS_ERR_FMT "%s: failed (line=%d)\n",
-                    ioc->name, __func__, __LINE__);
-                        goto out_free_resources;
-        }
-        spin_lock_irqsave(&ioc->ioc_reset_in_progress_lock, flags);
-        if (ioc->fault_reset_work_q)
-                queue_delayed_work(ioc->fault_reset_work_q,
-                    &ioc->fault_reset_work,
-                    msecs_to_jiffies(FAULT_POLLING_INTERVAL));
-        spin_unlock_irqrestore(&ioc->ioc_reset_in_progress_lock, flags);
+        mpt2sas_base_start_watchdog(ioc);
         return 0;
 
  out_free_resources:
@@ -3341,20 +3382,11 @@ mpt2sas_base_attach(struct MPT2SAS_ADAPTER *ioc)
 void
 mpt2sas_base_detach(struct MPT2SAS_ADAPTER *ioc)
 {
-        unsigned long    flags;
-        struct workqueue_struct *wq;
 
         dexitprintk(ioc, printk(MPT2SAS_DEBUG_FMT "%s\n", ioc->name,
             __func__));
 
-        spin_lock_irqsave(&ioc->ioc_reset_in_progress_lock, flags);
-        wq = ioc->fault_reset_work_q;
-        ioc->fault_reset_work_q = NULL;
-        spin_unlock_irqrestore(&ioc->ioc_reset_in_progress_lock, flags);
-        if (!cancel_delayed_work(&ioc->fault_reset_work))
-                flush_workqueue(wq);
-        destroy_workqueue(wq);
-
+        mpt2sas_base_stop_watchdog(ioc);
         mpt2sas_base_free_resources(ioc);
         _base_release_memory_pools(ioc);
         kfree(ioc->pfacts);
diff --git a/drivers/scsi/mpt2sas/mpt2sas_base.h b/drivers/scsi/mpt2sas/mpt2sas_base.h
index 286c185fa9e4..a29935726e7a 100644
--- a/drivers/scsi/mpt2sas/mpt2sas_base.h
+++ b/drivers/scsi/mpt2sas/mpt2sas_base.h
@@ -673,6 +673,8 @@ typedef void (*MPT_CALLBACK)(struct MPT2SAS_ADAPTER *ioc, u16 smid, u8 VF_ID,
 
 /* base shared API */
 extern struct list_head mpt2sas_ioc_list;
+void mpt2sas_base_start_watchdog(struct MPT2SAS_ADAPTER *ioc);
+void mpt2sas_base_stop_watchdog(struct MPT2SAS_ADAPTER *ioc);
 
 int mpt2sas_base_attach(struct MPT2SAS_ADAPTER *ioc);
 void mpt2sas_base_detach(struct MPT2SAS_ADAPTER *ioc);
diff --git a/drivers/scsi/mpt2sas/mpt2sas_scsih.c b/drivers/scsi/mpt2sas/mpt2sas_scsih.c
index 25c8d8294af6..2e9a4445596f 100644
--- a/drivers/scsi/mpt2sas/mpt2sas_scsih.c
+++ b/drivers/scsi/mpt2sas/mpt2sas_scsih.c
@@ -5824,6 +5824,7 @@ _scsih_suspend(struct pci_dev *pdev, pm_message_t state)
         struct MPT2SAS_ADAPTER *ioc = shost_priv(shost);
         u32 device_state;
 
+        mpt2sas_base_stop_watchdog(ioc);
         flush_scheduled_work();
         scsi_block_requests(shost);
         device_state = pci_choose_state(pdev, state);
@@ -5866,6 +5867,7 @@ _scsih_resume(struct pci_dev *pdev)
 
         mpt2sas_base_hard_reset_handler(ioc, CAN_SLEEP, SOFT_RESET);
         scsi_unblock_requests(shost);
+        mpt2sas_base_start_watchdog(ioc);
         return 0;
 }
 #endif /* CONFIG_PM */