From fe052529e465daff25225aac769828baa88b7252 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 22 Sep 2014 15:59:31 +0200 Subject: [PATCH] scsi: move blk_mq_start_request call earlier Some ATA drivers need the dma drain size workaround, and thus need to call blk_mq_start_request before the S/G mapping. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- drivers/scsi/scsi_lib.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 86b1156edb82..5c5617ec834f 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1846,6 +1846,8 @@ static int scsi_mq_prep_fn(struct request *req) next_rq->special = bidi_sdb; } + blk_mq_start_request(req); + return scsi_setup_cmnd(sdev, req); } @@ -1880,17 +1882,19 @@ static int scsi_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *req, if (!scsi_host_queue_ready(q, shost, sdev)) goto out_dec_target_busy; + if (!(req->cmd_flags & REQ_DONTPREP)) { ret = prep_to_mq(scsi_mq_prep_fn(req)); if (ret) goto out_dec_host_busy; req->cmd_flags |= REQ_DONTPREP; + } else { + blk_mq_start_request(req); } scsi_init_cmd_errh(cmd); cmd->scsi_done = scsi_mq_done; - blk_mq_start_request(req); reason = scsi_dispatch_cmd(cmd); if (reason) { scsi_set_blocked(cmd, reason); -- 2.20.1