Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block
* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
libata: fix NCQ devices behind port multipliers
scsi: make sure that scsi_init_shared_tag_map() doesn't overwrite existing map
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 4b95c43..bbb30d8 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -1107,6 +1107,15 @@
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);
}
diff --git a/include/scsi/scsi_tcq.h b/include/scsi/scsi_tcq.h
index cf4c219..1723138 100644
--- a/include/scsi/scsi_tcq.h
+++ b/include/scsi/scsi_tcq.h
@@ -140,8 +140,18 @@
*/
static inline int scsi_init_shared_tag_map(struct Scsi_Host *shost, int depth)
{
- shost->bqt = blk_init_tags(depth);
- return shost->bqt ? 0 : -ENOMEM;
+ /*
+ * If the shared tag map isn't already initialized, do it now.
+ * This saves callers from having to check ->bqt when setting up
+ * devices on the shared host (for libata)
+ */
+ if (!shost->bqt) {
+ shost->bqt = blk_init_tags(depth);
+ if (!shost->bqt)
+ return -ENOMEM;
+ }
+
+ return 0;
}
/**