[PATCH 05/12] hpsa: update discovery polling

[Don Brace <don.brace@xxxxxxxxxxxxx>]

From: Bader Ali Saleh <bader.alisaleh@xxxxxxxxxxxxx>

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 <scott.benesh@xxxxxxxxxxxxx>
Reviewed-by: Scott Teel <scott.teel@xxxxxxxxxxxxx>
Reviewed-by: Kevin Barnett <kevin.barnett@xxxxxxxxxxxxx>
Signed-off-by: Don Brace <don.brace@xxxxxxxxxxxxx>
---
 drivers/scsi/hpsa.c     |   39 ++++++++++++++++++++++++++-------------
 drivers/scsi/hpsa_cmd.h |    2 ++
 2 files changed, 28 insertions(+), 13 deletions(-)

diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
index 9c491c5..6056bbd 100644
--- a/drivers/scsi/hpsa.c
+++ b/drivers/scsi/hpsa.c
@@ -3472,6 +3472,30 @@ static void hpsa_get_sas_address(struct ctlr_info *h, unsigned char *scsi3addr,
 	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)
@@ -4228,6 +4252,8 @@ static void hpsa_update_scsi_devices(struct ctlr_info *h)
 	 */
 	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) {
@@ -4298,18 +4324,6 @@ static void hpsa_update_scsi_devices(struct ctlr_info *h)
 		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;
 
@@ -8247,7 +8261,6 @@ static void hpsa_rescan_ctlr_worker(struct work_struct *work)
 	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");
diff --git a/drivers/scsi/hpsa_cmd.h b/drivers/scsi/hpsa_cmd.h
index 78c3b64..21a726e 100644
--- a/drivers/scsi/hpsa_cmd.h
+++ b/drivers/scsi/hpsa_cmd.h
@@ -780,6 +780,8 @@ struct bmic_identify_physical_device {
 	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;