>From scsi driver view, it is a bit troublesome to support both blk-mq and non-blk-mq at the same time, especially when drivers need to support multi hw-queue.
This patch introduces 'force_blk_mq' to scsi_host_template so that drivers can provide blk-mq only support, so driver code can avoid the trouble for supporting both. Cc: Omar Sandoval <[email protected]>, Cc: "Martin K. Petersen" <[email protected]>, Cc: James Bottomley <[email protected]>, Cc: Christoph Hellwig <[email protected]>, Cc: Don Brace <[email protected]> Cc: Kashyap Desai <[email protected]> Cc: Mike Snitzer <[email protected]> Cc: Laurence Oberman <[email protected]> Reviewed-by: Hannes Reinecke <[email protected]> Signed-off-by: Ming Lei <[email protected]> --- drivers/scsi/hosts.c | 1 + include/scsi/scsi_host.h | 3 +++ 2 files changed, 4 insertions(+) diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c index 57bf43e34863..10f04b089392 100644 --- a/drivers/scsi/hosts.c +++ b/drivers/scsi/hosts.c @@ -477,6 +477,7 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) shost->dma_boundary = 0xffffffff; shost->use_blk_mq = scsi_use_blk_mq; + shost->use_blk_mq = scsi_use_blk_mq || !!shost->hostt->force_blk_mq; device_initialize(&shost->shost_gendev); dev_set_name(&shost->shost_gendev, "host%d", shost->host_no); diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h index 1a1df0d21ee3..6c6366f0bd15 100644 --- a/include/scsi/scsi_host.h +++ b/include/scsi/scsi_host.h @@ -452,6 +452,9 @@ struct scsi_host_template { /* True if the controller does not support WRITE SAME */ unsigned no_write_same:1; + /* True if the low-level driver supports blk-mq only */ + unsigned force_blk_mq:1; + /* * Countdown for host blocking with no commands outstanding. */ -- 2.9.5
