[PATCH 1/5] libsas: disable scanning lun > 0 on ata devices

[Dan Williams <dan.j.williams@intel.com>]

Currently mvsas and pm8001 have custom ->slave_alloc implementations to
achieve this.  Uplevel it for all libsas drivers as isci encounters problems
with atapi devices when scanning past lun0.

Just do what Darrick suggested [1], and limit the scan for ata devices.

[1] http://marc.info/?l=linux-scsi&m=116604101119861&w=2

Cc: Darrick Wong <djwong@us.ibm.com>
Cc: Xiangliang Yu <yuxiangl@marvell.com>
Cc: Jack Wang <jack_wang@usish.com>
Cc: Mark Salyzyn <msalyzyn@us.xyratex.com>
Cc: Luben Tuikov <ltuikov@yahoo.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/scsi/scsi_transport_sas.c |   10 ++++++++--
 1 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/scsi_transport_sas.c b/drivers/scsi/scsi_transport_sas.c
index c6fcf76..9d9330a 100644
--- a/drivers/scsi/scsi_transport_sas.c
+++ b/drivers/scsi/scsi_transport_sas.c
@@ -1545,8 +1545,14 @@ int sas_rphy_add(struct sas_rphy *rphy)
 
 	if (identify->device_type == SAS_END_DEVICE &&
 	    rphy->scsi_target_id != -1) {
-		scsi_scan_target(&rphy->dev, 0,
-				rphy->scsi_target_id, SCAN_WILD_CARD, 0);
+		int lun;
+
+		if (identify->target_port_protocols & SAS_PROTOCOL_SSP)
+			lun = SCAN_WILD_CARD;
+		else
+			lun = 0;
+
+		scsi_scan_target(&rphy->dev, 0, rphy->scsi_target_id, lun, 0);
 	}
 
 	return 0;