hpsa: Retry driver initiated commands on unit attention.

There are a some commands initiated by the driver which
are neither ioctls nor normal i/o.  If any of these commands
completes with UNIT ATTENTION, they should be retried.
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Mike Miller <mikem@beardog.cce.hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/scsi/hpsa.c

@@ -1173,7 +1173,7 @@ static void hpsa_map_one(struct pci_dev *pdev,
 	cp->Header.SGTotal = (__u16) 1; /* total sgs in this cmd list */
 }
 
-static void hpsa_scsi_do_simple_cmd_core(struct ctlr_info *h,
+static inline void hpsa_scsi_do_simple_cmd_core(struct ctlr_info *h,
 	struct CommandList *c)
 {
 	DECLARE_COMPLETION_ONSTACK(wait);
@@ -1183,6 +1183,19 @@ static void hpsa_scsi_do_simple_cmd_core(struct ctlr_info *h,
 	wait_for_completion(&wait);
 }
 
+static void hpsa_scsi_do_simple_cmd_with_retry(struct ctlr_info *h,
+	struct CommandList *c, int data_direction)
+{
+	int retry_count = 0;
+
+	do {
+		memset(c->err_info, 0, sizeof(c->err_info));
+		hpsa_scsi_do_simple_cmd_core(h, c);
+		retry_count++;
+	} while (check_for_unit_attention(h, c) && retry_count <= 3);
+	hpsa_pci_unmap(h->pdev, c, 1, data_direction);
+}
+
 static void hpsa_scsi_interpret_error(struct CommandList *cp)
 {
 	struct ErrorInfo *ei;
@@ -1262,9 +1275,7 @@ static int hpsa_scsi_do_inquiry(struct ctlr_info *h, unsigned char *scsi3addr,
 	rc = fill_cmd(c, HPSA_INQUIRY, h, buf, bufsize, page, scsi3addr,
 		TYPE_CMD);
 	if (rc == 0) {
-		hpsa_scsi_do_simple_cmd_core(h, c);
-		hpsa_pci_unmap(h->pdev, c, 1, PCI_DMA_FROMDEVICE);
-
+		hpsa_scsi_do_simple_cmd_with_retry(h, c, PCI_DMA_FROMDEVICE);
 		ei = c->err_info;
 		if (ei->CommandStatus != 0 &&
 		    ei->CommandStatus != CMD_DATA_UNDERRUN) {
@@ -1369,8 +1380,7 @@ static int hpsa_scsi_do_report_luns(struct ctlr_info *h, int logical,
 
 	if (extended_response)
 		c->Request.CDB[1] = extended_response;
-	hpsa_scsi_do_simple_cmd_core(h, c);
-	hpsa_pci_unmap(h->pdev, c, 1, PCI_DMA_FROMDEVICE);
+	hpsa_scsi_do_simple_cmd_with_retry(h, c, PCI_DMA_FROMDEVICE);
 	ei = c->err_info;
 	if (ei->CommandStatus != 0 &&
 	    ei->CommandStatus != CMD_DATA_UNDERRUN) {