From: Xiang Chen <chenxiang66@hisilicon.com>
Date: Sat, 9 Dec 2017 01:16:33 +0800
Subject: scsi: hisi_sas: fix dma_unmap_sg() parameter
Git-commit: dc1e4730e2b636065628f8427b675788bca83d34
Patch-mainline: v4.16-rc1
References: FATE#326253

For function dma_unmap_sg(), the <nents> parameter should be number of
elements in the scatterlist prior to the mapping, not after the mapping.

Fix this usage.

Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Johannes Thumshirn <jthumshirn@suse.de>
---
 drivers/scsi/hisi_sas/hisi_sas_main.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c
index 359ec52fc2fb..d8425303eadd 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_main.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
@@ -192,7 +192,8 @@ void hisi_sas_slot_task_free(struct hisi_hba *hisi_hba, struct sas_task *task,
 
 		if (!sas_protocol_ata(task->task_proto))
 			if (slot->n_elem)
-				dma_unmap_sg(dev, task->scatter, slot->n_elem,
+				dma_unmap_sg(dev, task->scatter,
+					     task->num_scatter,
 					     task->data_dir);
 
 		if (sas_dev)
@@ -431,7 +432,8 @@ static int hisi_sas_task_prep(struct sas_task *task, struct hisi_sas_dq
 	dev_err(dev, "task prep: failed[%d]!\n", rc);
 	if (!sas_protocol_ata(task->task_proto))
 		if (n_elem)
-			dma_unmap_sg(dev, task->scatter, n_elem,
+			dma_unmap_sg(dev, task->scatter,
+				     task->num_scatter,
 				     task->data_dir);
 prep_out:
 	return rc;