scsi: hisi_sas: Move evaluation of hisi_hba in hisi_sas_task_prep()

In evaluating hisi_hba, the sas_port may be NULL, so for safety relocate
the the check to value possible NULL deference.

Signed-off-by: Luo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c
index 791787b..a084311 100644 (file)
--- a/drivers/scsi/hisi_sas/hisi_sas_main.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
@@ -287,13 +287,13 @@ static int hisi_sas_task_prep(struct sas_task *task,
                              int *pass)
 {
        struct domain_device *device = task->dev;
-       struct hisi_hba *hisi_hba = dev_to_hisi_hba(device);
+       struct hisi_hba *hisi_hba;
        struct hisi_sas_device *sas_dev = device->lldd_dev;
        struct hisi_sas_port *port;
        struct hisi_sas_slot *slot;
        struct hisi_sas_cmd_hdr *cmd_hdr_base;
        struct asd_sas_port *sas_port = device->port;
-       struct device *dev = hisi_hba->dev;
+       struct device *dev;
        int dlvry_queue_slot, dlvry_queue, rc, slot_idx;
        int n_elem = 0, n_elem_req = 0, n_elem_resp = 0;
        struct hisi_sas_dq *dq;
@@ -314,6 +314,9 @@ static int hisi_sas_task_prep(struct sas_task *task,
                return -ECOMM;
        }
 
+       hisi_hba = dev_to_hisi_hba(device);
+       dev = hisi_hba->dev;
+
        if (DEV_IS_GONE(sas_dev)) {
                if (sas_dev)
                        dev_info(dev, "task prep: device %d not ready\n",