[PATCH 01/10] hpsa: do not attempt to flush the cache on locked up controllers

["Stephen M. Cameron" <scameron@beardog.cce.hp.com>]

From: Stephen M. Cameron <scameron@beardog.cce.hp.com>

There's no point in trying since it can't work, and if you do
try, it will just hang the system on shutdown.

Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
---
 drivers/scsi/hpsa.c |    9 +++++++++
 1 files changed, 9 insertions(+), 0 deletions(-)

diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
index 891c86b..d6ddc7f 100644
--- a/drivers/scsi/hpsa.c
+++ b/drivers/scsi/hpsa.c
@@ -4942,6 +4942,15 @@ static void hpsa_flush_cache(struct ctlr_info *h)
 {
 	char *flush_buf;
 	struct CommandList *c;
+	unsigned long flags;
+
+	/* Don't bother trying to flush the cache if locked up */
+	spin_lock_irqsave(&h->lock, flags);
+	if (unlikely(h->lockup_detected)) {
+		spin_unlock_irqrestore(&h->lock, flags);
+		return;
+	}
+	spin_unlock_irqrestore(&h->lock, flags);
 
 	flush_buf = kzalloc(4, GFP_KERNEL);
 	if (!flush_buf)