[PATCH 07/10] qla2xxx: Fix discovery issues in FC-AL topology

[Nilesh Javali <njavali@marvell.com>]

From: Arun Easi <aeasi@marvell.com>

A direct attach tape device, when gets swapped
with another, was not discovered. Fix this by
looking at loop map and reinitialize link if
there are devices present.

Reported-by: Tony Battersby <tonyb@cybernetics.com>
Tested-by: Tony Battersby <tonyb@cybernetics.com>
Link: https://lore.kernel.org/linux-scsi/baef87c3-5dad-3b47-44c1-6914bfc90108@cybernetics.com/
Cc: stable@vger.kernel.org
Signed-off-by: Arun Easi <aeasi@marvell.com>
Signed-off-by: Nilesh Javali <njavali@marvell.com>
---
 drivers/scsi/qla2xxx/qla_gbl.h  |  3 ++-
 drivers/scsi/qla2xxx/qla_init.c | 29 +++++++++++++++++++++++++++++
 drivers/scsi/qla2xxx/qla_mbx.c  |  5 ++++-
 3 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/qla2xxx/qla_gbl.h b/drivers/scsi/qla2xxx/qla_gbl.h
index 96147ca40126..5dd2932382ee 100644
--- a/drivers/scsi/qla2xxx/qla_gbl.h
+++ b/drivers/scsi/qla2xxx/qla_gbl.h
@@ -436,7 +436,8 @@ extern int
 qla2x00_get_resource_cnts(scsi_qla_host_t *);
 
 extern int
-qla2x00_get_fcal_position_map(scsi_qla_host_t *ha, char *pos_map);
+qla2x00_get_fcal_position_map(scsi_qla_host_t *ha, char *pos_map,
+		u8 *num_entries);
 
 extern int
 qla2x00_get_link_status(scsi_qla_host_t *, uint16_t, struct link_statistics *,
diff --git a/drivers/scsi/qla2xxx/qla_init.c b/drivers/scsi/qla2xxx/qla_init.c
index 83fae4c341ee..e7fe0e52c11d 100644
--- a/drivers/scsi/qla2xxx/qla_init.c
+++ b/drivers/scsi/qla2xxx/qla_init.c
@@ -5516,6 +5516,22 @@ static int qla2x00_configure_n2n_loop(scsi_qla_host_t *vha)
 	return QLA_FUNCTION_FAILED;
 }
 
+static void
+qla_reinitialize_link(scsi_qla_host_t *vha)
+{
+	int rval;
+
+	atomic_set(&vha->loop_state, LOOP_DOWN);
+	atomic_set(&vha->loop_down_timer, LOOP_DOWN_TIME);
+	rval = qla2x00_full_login_lip(vha);
+	if (rval == QLA_SUCCESS) {
+		ql_dbg(ql_dbg_disc, vha, 0xd050, "Link reinitialized\n");
+	} else {
+		ql_dbg(ql_dbg_disc, vha, 0xd051,
+			"Link reinitialization failed (%d)\n", rval);
+	}
+}
+
 /*
  * qla2x00_configure_local_loop
  *	Updates Fibre Channel Device Database with local loop devices.
@@ -5567,6 +5583,19 @@ qla2x00_configure_local_loop(scsi_qla_host_t *vha)
 		spin_unlock_irqrestore(&vha->work_lock, flags);
 
 		if (vha->scan.scan_retry < MAX_SCAN_RETRIES) {
+			u8 loop_map_entries = 0;
+			int rc;
+
+			rc = qla2x00_get_fcal_position_map(vha, NULL,
+						&loop_map_entries);
+			if (rc == QLA_SUCCESS && loop_map_entries > 1) {
+				/*
+				 * There are devices that are still not logged
+				 * in. Reinitialize to give them a chance.
+				 */
+				qla_reinitialize_link(vha);
+				return QLA_FUNCTION_FAILED;
+			}
 			set_bit(LOCAL_LOOP_UPDATE, &vha->dpc_flags);
 			set_bit(LOOP_RESYNC_NEEDED, &vha->dpc_flags);
 		}
diff --git a/drivers/scsi/qla2xxx/qla_mbx.c b/drivers/scsi/qla2xxx/qla_mbx.c
index 9a3f832c49ef..359595a64664 100644
--- a/drivers/scsi/qla2xxx/qla_mbx.c
+++ b/drivers/scsi/qla2xxx/qla_mbx.c
@@ -3068,7 +3068,8 @@ qla2x00_get_resource_cnts(scsi_qla_host_t *vha)
  *	Kernel context.
  */
 int
-qla2x00_get_fcal_position_map(scsi_qla_host_t *vha, char *pos_map)
+qla2x00_get_fcal_position_map(scsi_qla_host_t *vha, char *pos_map,
+		u8 *num_entries)
 {
 	int rval;
 	mbx_cmd_t mc;
@@ -3108,6 +3109,8 @@ qla2x00_get_fcal_position_map(scsi_qla_host_t *vha, char *pos_map)
 
 		if (pos_map)
 			memcpy(pos_map, pmap, FCAL_MAP_SIZE);
+		if (num_entries)
+			*num_entries = pmap[0];
 	}
 	dma_pool_free(ha->s_dma_pool, pmap, pmap_dma);
 
-- 
2.19.0.rc0