[PATCH][Disco] scsi: libsas: Check SMP PHY control function result

[dann frazier]

From: John Garry <john.garry at huawei.com>

BugLink: https://bugs.launchpad.net/bugs/1822680

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 at huawei.com>
Signed-off-by: John Garry <john.garry at huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen at oracle.com>
(cherry picked from commit 01929a65dfa13e18d89264ab1378854a91857e59)
Signed-off-by: dann frazier <dann.frazier at canonical.com>
---
 drivers/scsi/libsas/sas_expander.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c
index b5d31e7cbbf1f..bc0bdd4eafe62 100644
--- a/drivers/scsi/libsas/sas_expander.c
+++ b/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;
-- 
2.20.1