[PATCH 2/2] scsi: set sc_data_direction to DMA_NONE for no-transfer commands

[Christoph Hellwig <hch@xxxxxx>]

No having the special DMA_NONE logic makes libata rather unhappy.

Fixes: 40b93836a136 ("scsi: core: Use rq_dma_dir in scsi_setup_cmnd()")
Reported-by: Qian Cai <cai@xxxxxxxxxx>
Reported-by: Naresh Kamboju <naresh.kamboju@xxxxxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
 drivers/scsi/scsi_lib.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 6b0fccda9af2ee..1a2e9bab42efab 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1545,7 +1545,10 @@ static blk_status_t scsi_prepare_cmd(struct request *req)
 	cmd->request = req;
 	cmd->tag = req->tag;
 	cmd->prot_op = SCSI_PROT_NORMAL;
-	cmd->sc_data_direction = rq_dma_dir(req);
+	if (blk_rq_bytes(req))
+		cmd->sc_data_direction = rq_dma_dir(req);
+	else
+		cmd->sc_data_direction = DMA_NONE;
 
 	sg = (void *)cmd + sizeof(struct scsi_cmnd) + shost->hostt->cmd_size;
 	cmd->sdb.table.sgl = sg;
-- 
2.28.0