scsi: add support for multiple hardware queues

Allow a SCSI LLD to declare how many hardware queues it supports
by setting Scsi_Host.nr_hw_queues before calling scsi_add_host().

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index fc0a8a0c0a34..38f8c85957b6 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -2106,7 +2106,7 @@ int scsi_mq_setup_tags(struct Scsi_Host *shost)
 
         memset(&shost->tag_set, 0, sizeof(shost->tag_set));
         shost->tag_set.ops = &scsi_mq_ops;
-        shost->tag_set.nr_hw_queues = 1;
+        shost->tag_set.nr_hw_queues = shost->nr_hw_queues ? : 1;
         shost->tag_set.queue_depth = shost->can_queue;
         shost->tag_set.cmd_size = cmd_size;
         shost->tag_set.numa_node = NUMA_NO_NODE;