The function csio_config_device_caps() defined in file drivers/scsi/csiostor/csio_hw.c returns the value of variable rv at the end. By reviewing the source code of the caller of csio_config_device_caps(), we can infer that variable rv should takes a non-zero value on failures. However, after the check of variable rv at line 1376, its value must be 0. As a result, 0 will be returned even if the subsequent calls to csio_mb_issue() (at line 1389) or csio_mb_fw_retval() (at line 1394) fails. I guess letting rv receives the return value of csio_hw_validate_caps() at line 1375 may be a typo. Does the author means "retval" instead of "rv"? Codes related to this bug are summarised as follows.

csio_config_device_caps @@ drivers/scsi/csiostor/csio_hw.c
1347 static int
1348 csio_config_device_caps(struct csio_hw *hw)
1349 {
1350     struct csio_mb  *mbp;
1351     enum fw_retval retval;
1352     int rv = -EINVAL;
1353 
1354     mbp = mempool_alloc(hw->mb_mempool, GFP_ATOMIC);
1355     if (!mbp) {
1356         CSIO_INC_STATS(hw, n_err_nomem);
1357         return -ENOMEM;
1358     }
         ...
1374     /* Validate device capabilities */
1375     rv = csio_hw_validate_caps(hw, mbp); // use "retval" instead of "rv"?
1376     if (rv != 0)
1377         goto out;
1378 
1379     /* Don't config device capabilities if already configured */
1380     if (hw->fw_state == CSIO_DEV_STATE_INIT) {
1381         rv = 0;
1382         goto out;
1383     }
1384 
1385     /* Write back desired device capabilities */
1386     csio_mb_caps_config(hw, mbp, CSIO_MB_DEFAULT_TMO, true, true,
1387                 false, true, NULL);
1388 
1389     if (csio_mb_issue(hw, mbp)) {
1390         csio_err(hw, "Issue of FW_CAPS_CONFIG_CMD(w) failed!\n");
             // on this error, the return value is 0
1391         goto out;
1392     }
1393 
1394     retval = csio_mb_fw_retval(mbp);
1395     if (retval != FW_SUCCESS) {
1396         csio_err(hw, "FW_CAPS_CONFIG_CMD(w) returned %d!\n", retval);
             // on this error, the return value is 0
1397         goto out;
1398     }
1399 
1400     rv = 0;
1401 out:
1402     mempool_free(mbp, hw->mb_mempool);
1403     return rv;
1404 }

Thanks very much!