libata: fix NCQ devices behind port multipliers

For devices behind sata port multipliers, we have to make sure that
they share a tag map since all tags for that PMP must be unique.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 4b95c4387e9e..bbb30d882f05 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -1107,6 +1107,15 @@ static int ata_scsi_dev_config(struct scsi_device *sdev,
 
                 depth = min(sdev->host->can_queue, ata_id_queue_depth(dev->id));
                 depth = min(ATA_MAX_QUEUE - 1, depth);
+
+                /*
+                 * If this device is behind a port multiplier, we have
+                 * to share the tag map between all devices on that PMP.
+                 * Set up the shared tag map here and we get automatic.
+                 */
+                if (dev->link->ap->pmp_link)
+                        scsi_init_shared_tag_map(sdev->host, ATA_MAX_QUEUE - 1);
+
                 scsi_set_tag_type(sdev, MSG_SIMPLE_TAG);
                 scsi_activate_tcq(sdev, depth);
         }