[bug report] scsi: ufs: core: mcq: Configure resource regions

[Dan Carpenter <error27@gmail.com>]

Hello Asutosh Das,

The patch c263b4ef737e: "scsi: ufs: core: mcq: Configure resource
regions" from Jan 13, 2023, leads to the following Smatch static
checker warning:

drivers/ufs/host/ufs-qcom.c:1455 ufs_qcom_mcq_config_resource() warn: passing zero to 'PTR_ERR'
drivers/ufs/host/ufs-qcom.c:1469 ufs_qcom_mcq_config_resource() info: returning a literal zero is cleaner

drivers/ufs/host/ufs-qcom.c
    1425 static int ufs_qcom_mcq_config_resource(struct ufs_hba *hba)
    1426 {
    1427         struct platform_device *pdev = to_platform_device(hba->dev);
    1428         struct ufshcd_res_info *res;
    1429         struct resource *res_mem, *res_mcq;
    1430         int i, ret = 0;
    1431 
    1432         memcpy(hba->res, ufs_res_info, sizeof(ufs_res_info));
    1433 
    1434         for (i = 0; i < RES_MAX; i++) {
    1435                 res = &hba->res[i];
    1436                 res->resource = platform_get_resource_byname(pdev,
    1437                                                              IORESOURCE_MEM,
    1438                                                              res->name);
    1439                 if (!res->resource) {
    1440                         dev_info(hba->dev, "Resource %s not provided\n", res->name);
    1441                         if (i == RES_UFS)
    1442                                 return -ENOMEM;
    1443                         continue;
    1444                 } else if (i == RES_UFS) {
    1445                         res_mem = res->resource;
    1446                         res->base = hba->mmio_base;
    1447                         continue;
    1448                 }
    1449 
    1450                 res->base = devm_ioremap_resource(hba->dev, res->resource);
    1451                 if (IS_ERR(res->base)) {
    1452                         dev_err(hba->dev, "Failed to map res %s, err=%d\n",
    1453                                          res->name, (int)PTR_ERR(res->base));
    1454                         res->base = NULL;
                                 ^^^^^^^^^^^^^^^^

--> 1455                         ret = PTR_ERR(res->base);
                                 ^^^^^^^^^^^^^^^^^^^^^^^^
Need to preserve the error code beforse setting this to NULL.

    1456                         return ret;
    1457                 }
    1458         }
    1459 
    1460         /* MCQ resource provided in DT */
    1461         res = &hba->res[RES_MCQ];
    1462         /* Bail if MCQ resource is provided */
    1463         if (res->base)
    1464                 goto out;
    1465 
    1466         /* Explicitly allocate MCQ resource from ufs_mem */
    1467         res_mcq = devm_kzalloc(hba->dev, sizeof(*res_mcq), GFP_KERNEL);
    1468         if (!res_mcq)
    1469                 return ret;

Return -ENOMEM;

    1470 
    1471         res_mcq->start = res_mem->start +
    1472                          MCQ_SQATTR_OFFSET(hba->mcq_capabilities);
    1473         res_mcq->end = res_mcq->start + hba->nr_hw_queues * MCQ_QCFG_SIZE - 1;
    1474         res_mcq->flags = res_mem->flags;
    1475         res_mcq->name = "mcq";
    1476 
    1477         ret = insert_resource(&iomem_resource, res_mcq);
    1478         if (ret) {
    1479                 dev_err(hba->dev, "Failed to insert MCQ resource, err=%d\n",
    1480                         ret);
    1481                 goto insert_res_err;
    1482         }
    1483 
    1484         res->base = devm_ioremap_resource(hba->dev, res_mcq);
    1485         if (IS_ERR(res->base)) {
    1486                 dev_err(hba->dev, "MCQ registers mapping failed, err=%d\n",
    1487                         (int)PTR_ERR(res->base));
    1488                 ret = PTR_ERR(res->base);
    1489                 goto ioremap_err;
    1490         }
    1491 
    1492 out:
    1493         hba->mcq_base = res->base;
    1494         return 0;
    1495 ioremap_err:
    1496         res->base = NULL;
    1497         remove_resource(res_mcq);
    1498 insert_res_err:
    1499         devm_kfree(hba->dev, res_mcq);

No need to call devm_kfree().  The whole point of devm_ is that it's
automatic.

    1500         return ret;
    1501 }

regards,
dan carpenter