scsi: libsas: Check SMP PHY control function result

Currently the SMP PHY control execution result is checked, however the
function result for the command is not.

As such, we may be missing all potential errors, like SMP FUNCTION FAILED,
INVALID REQUEST FRAME LENGTH, etc., meaning the PHY control request has
failed.

In some scenarios we need to ensure the function result is accepted, so add
a check for this.
Tested-by: Jian Luo <luojian5@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/libsas/sas_expander.c

@@ -614,7 +614,14 @@ int sas_smp_phy_control(struct domain_device *dev, int phy_id,
 	}
 
 	res = smp_execute_task(dev, pc_req, PC_REQ_SIZE, pc_resp,PC_RESP_SIZE);
-
+	if (res) {
+		pr_err("ex %016llx phy%02d PHY control failed: %d\n",
+		       SAS_ADDR(dev->sas_addr), phy_id, res);
+	} else if (pc_resp[2] != SMP_RESP_FUNC_ACC) {
+		pr_err("ex %016llx phy%02d PHY control failed: function result 0x%x\n",
+		       SAS_ADDR(dev->sas_addr), phy_id, pc_resp[2]);
+		res = pc_resp[2];
+	}
 	kfree(pc_resp);
 	kfree(pc_req);
 	return res;