scsi: hpsa: update discovery polling

Correct a corner case where newly created volumes are not detected
automatically on an external RAID controller that has no configured
volumes during initial device discovery.

The fix is to set the discovery_polling flag when an external RAID
controller is detected. This causes a device rescan every 20-30 seconds,
so that newly created volumes will be detected automatically.

Reviewed-by: Scott Benesh <[e-mail]>
Reviewed-by: Scott Teel <[e-mail]>
Reviewed-by: Kevin Barnett <[e-mail]>
Signed-off-by: Don Brace <[e-mail]>
Signed-off-by: Martin K. Petersen <[e-mail]>

drivers/scsi/hpsa.c

···
 	dev->sas_address = sa;
 }
 
+static void hpsa_ext_ctrl_present(struct ctlr_info *h,
+	struct ReportExtendedLUNdata *physdev)
+{
+	u32 nphysicals;
+	int i;
+
+	if (h->discovery_polling)
+		return;
+
+	nphysicals = (get_unaligned_be32(physdev->LUNListLength) / 24) + 1;
+
+	for (i = 0; i < nphysicals; i++) {
+		if (physdev->LUN[i].device_type ==
+			BMIC_DEVICE_TYPE_CONTROLLER
+			&& !is_hba_lunid(physdev->LUN[i].lunid)) {
+			dev_info(&h->pdev->dev,
+				"External controller present, activate discovery polling and disable rld caching\n");
+			hpsa_disable_rld_caching(h);
+			h->discovery_polling = 1;
+			break;
+		}
+	}
+}
+
 /* Get a device id from inquiry page 0x83 */
 static bool hpsa_vpd_page_supported(struct ctlr_info *h,
 	unsigned char scsi3addr[], u8 page)
···
 	 */
 	ndevs_to_allocate = nphysicals + nlogicals + MAX_EXT_TARGETS + 1;
 
+	hpsa_ext_ctrl_present(h, physdev_list);
+
 	/* Allocate the per device structures */
 	for (i = 0; i < ndevs_to_allocate; i++) {
 		if (i >= HPSA_MAX_DEVICES) {
···
 
 		figure_bus_target_lun(h, lunaddrbytes, tmpdevice);
 		this_device = currentsd[ncurrent];
-
-		/* Turn on discovery_polling if there are ext target devices.
-		 * Event-based change notification is unreliable for those.
-		 */
-		if (!h->discovery_polling) {
-			if (tmpdevice->external) {
-				h->discovery_polling = 1;
-				dev_info(&h->pdev->dev,
-					"External target, activate discovery polling.\n");
-			}
-		}
-
 
 		*this_device = *tmpdevice;
 		this_device->physical_device = physical_device;
···
 	if (h->drv_req_rescan || hpsa_offline_devices_ready(h)) {
 		hpsa_perform_rescan(h);
 	} else if (h->discovery_polling) {
-		hpsa_disable_rld_caching(h);
 		if (hpsa_luns_changed(h)) {
 			dev_info(&h->pdev->dev,
 				"driver discovery polling rescan.\n");

drivers/scsi/hpsa_cmd.h

···
 	u8     phys_bay_in_box;  /* phys drv bay this drive resides */
 	__le32 rpm;              /* Drive rotational speed in rpm */
 	u8     device_type;       /* type of drive */
+#define BMIC_DEVICE_TYPE_CONTROLLER	0x07
+
 	u8     sata_version;     /* only valid when drive_type is SATA */
 	__le64 big_total_block_count;
 	__le64 ris_starting_lba;