(raid->regTypeReqOnRead != REGION_TYPE_UNUSED))))
                        pRAID_Context->regLockFlags = REGION_TYPE_EXCLUSIVE;
                else if (raid->level == 1) {
-                       pd = MR_ArPdGet(arRef, physArm + 1, map);
+                       physArm = physArm + 1;
+                       pd = MR_ArPdGet(arRef, physArm, map);
                        if (pd != MR_PD_INVALID)
                                *pDevHandle = MR_PdDevHandleGet(pd, map);
                }
                        pRAID_Context->regLockFlags = REGION_TYPE_EXCLUSIVE;
                else if (raid->level == 1) {
                        /* Get alternate Pd. */
-                       pd = MR_ArPdGet(arRef, physArm + 1, map);
+                       physArm = physArm + 1;
+                       pd = MR_ArPdGet(arRef, physArm, map);
                        if (pd != MR_PD_INVALID)
                                /* Get dev handle from Pd */
                                *pDevHandle = MR_PdDevHandleGet(pd, map);