megaraid_sas: Make tape drives visible on PERC5 controllers

The DELL PERC5 controller firmware does not list tape drives in response
to MR_DCMD_PD_LIST_QUERY. This causes tape drives not be exposed to the
OS when connected to a PERC5 controller.

This patch permits detection of tape drives connected to a PERC5
controller by exposing non-TYPE_DISK devices unconditionally.
Signed-off-by: Kashyap Desai <kashyap.desai@avagotech.com>
Signed-off-by: Sumit Saxena <sumit.saxena@avagotech.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/megaraid/megaraid_sas.h

@@ -1790,6 +1790,7 @@ struct megasas_instance {
 	u8 UnevenSpanSupport;
 
 	u8 supportmax256vd;
+	u8 allow_fw_scan;
 	u16 fw_supported_vd_count;
 	u16 fw_supported_pd_count;
 

drivers/scsi/megaraid/megaraid_sas_base.c

@@ -1760,6 +1760,20 @@ static void megasas_set_dma_alignment(struct scsi_device *sdev)
 
 static int megasas_slave_configure(struct scsi_device *sdev)
 {
+	u16 pd_index = 0;
+	struct megasas_instance *instance;
+
+	instance = megasas_lookup_instance(sdev->host->host_no);
+	if (instance->allow_fw_scan) {
+		if (sdev->channel < MEGASAS_MAX_PD_CHANNELS &&
+			sdev->type == TYPE_DISK) {
+			pd_index = (sdev->channel * MEGASAS_MAX_DEV_PER_CHANNEL) +
+				sdev->id;
+			if (instance->pd_list[pd_index].driveState !=
+				MR_PD_STATE_SYSTEM)
+				return -ENXIO;
+		}
+	}
 	megasas_set_dma_alignment(sdev);
 	/*
 	 * The RAID firmware may require extended timeouts.
@@ -1783,9 +1797,8 @@ static int megasas_slave_alloc(struct scsi_device *sdev)
 		pd_index =
 			(sdev->channel * MEGASAS_MAX_DEV_PER_CHANNEL) +
 			sdev->id;
-		if ((instance->pd_list[pd_index].driveState ==
-			MR_PD_STATE_SYSTEM) ||
-			(instance->pd_list[pd_index].driveType != TYPE_DISK)) {
+		if ((instance->allow_fw_scan || instance->pd_list[pd_index].driveState ==
+			MR_PD_STATE_SYSTEM)) {
 			return 0;
 		}
 		return -ENXIO;
@@ -4699,6 +4712,7 @@ static int megasas_init_fw(struct megasas_instance *instance)
 	case PCI_DEVICE_ID_DELL_PERC5:
 	default:
 		instance->instancet = &megasas_instance_template_xscale;
+		instance->allow_fw_scan = 1;
 		break;
 	}