improve transport error handling. To fix report of a BAD_TARGET transport error but the utility still continued. introduce SG_LIB_TRANSPORT_ERROR [35] exit status

git-svn-id: https://svn.bingwo.ca/repos/sg3_utils/trunk@910 6180dd3e-e324-4e3e-922d-17de1ae2f315

35 files changed, 531 insertions, 287 deletions

diff --git a/COVERAGE b/COVERAGE
index 3c5c9ffa..434ebc21 100644
--- a/COVERAGE
+++ b/COVERAGE
@@ -46,8 +46,8 @@ ORWRITE(32)         sg_write_x
 PERSISTENT RESERVE IN       sg_persist, ++
 PERSISTENT RESERVE OUT      sg_persist, ++
 POPULATE TOKEN      ddpt, ddptctl, ++
-PRE-FETCH(10)	    sg_seek
-PRE-FETCH(16)	    sg_seek
+PRE-FETCH(10)       sg_seek
+PRE-FETCH(16)       sg_seek
 PREVENT ALLOW MEDIUM REMOVAL        sg_prevent, ++
 READ(6)             sg_dd, sgm_dd, sgp_dd, sg_read
 READ(10)            sg_dd, sgm_dd, sgp_dd, sg_read
@@ -76,18 +76,18 @@ REPORT ALL ROD TOKENS    ddptctl ++
 REPORT IDENTIFYING INFORMATION  sg_ident, ++ (2)
 REPORT LUNS         sg_luns, ++
 REPORT PROVISIONING INITIALIZATION PATTERN    sg_rep_pip, ++
+REPORT REALMS       sg_rep_zones
 REPORT REFERRALS    sg_referrals, ++
 REPORT SUPPORTED OPERATION CODES              sg_opcodes
 REPORT SUPPORTED TASK MANAGEMENT FUNCTIONS    sg_opcodes
 REPORT TARGET PORT GROUPS       sg_rtpg, sg_stpg ++
 REPORT TIMESTAMP    sg_timestamp
-REPORT ZONE DOMAINS  sg_rep_zones
-REPORT REALMS       sg_rep_zones
 REPORT ZONES        sg_rep_zones
+REPORT ZONE DOMAINS  sg_rep_zones
 REQUEST SENSE       sg_requests, ++
 RESET WRITE POINTER sg_reset_wp
 SANITIZE            sg_sanitize
-SEEK(10)	    sg_seek ++
+SEEK(10)            sg_seek ++
 SEND DIAGNOSTIC     sg_senddiag, sg_ses, sg_ses_microcode ++
 SEQUENTIALIZE ZONE  sg_zone
 SET IDENTIFYING INFORMATION  sg_ident, ++ (3)
@@ -156,7 +156,7 @@ Write zeroes        [SCSI WRITE SAME(10,zeros) -->SNTL--> Write zeroes]
                     [SCSI WRITE SAME(16,zeros) -->SNTL--> Write zeroes]
 Flush               [SCSI SYNCHRONIZE CACHE -->SNTL--> Flush]
 Set Features        [SCSI MODE SELECT(10) -->SNTL--> Set Features]
-		       only for WCE in Caching page
+                       only for WCE in Caching page
 
 The following SCSI commands do nothing (currently) in the SNTL but
 do return GOOD status: TEST UNIT READY, START STOP UNIT, REPORT LUNS
@@ -180,4 +180,4 @@ THIRD PARTY COPY IN (0x83).
 
 
 Douglas Gilbert
-7th June 2021
+30th August 2021
diff --git a/ChangeLog b/ChangeLog
index 906c3ceb..a1c8ce01 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -2,7 +2,10 @@ Each utility has its own version number, date of last change and
 some description at the top of its ".c" file. All utilities in the main
 directory have their own "man" pages. There is also a sg3_utils man page.
 
-Changelog for pre-release sg3_utils-1.47 [20210816] [svn: r909]
+Changelog for pre-release sg3_utils-1.47 [20210830] [svn: r910]
+  - transport error handling improved. To fix report of a
+    BAD_TARGET transport error but the utility still continued.
+    - introduce SG_LIB_TRANSPORT_ERROR [35] exit status
   - sg_rep_zones: add support for REPORT ZONE DOMAINS and
     REPORT REALMS in this utility
   - sg_raw: fix prints of NVMe NVM command names
diff --git a/debian/changelog b/debian/changelog
index 69bbf786..58bc639d 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -2,7 +2,7 @@ sg3-utils (1.47-0.1) unstable; urgency=low
 
   * New upstream version
 
- -- Douglas Gilbert <dgilbert@interlog.com>  Mon, 16 Aug 2021 17:00:00 -0400
+ -- Douglas Gilbert <dgilbert@interlog.com>  Mon, 30 Aug 2021 17:00:00 -0400
 
 sg3-utils (1.46-0.1) unstable; urgency=low
 
diff --git a/doc/sg3_utils.8 b/doc/sg3_utils.8
index a8ad41ec..d4ff0456 100644
--- a/doc/sg3_utils.8
+++ b/doc/sg3_utils.8
@@ -441,6 +441,12 @@ this is a Windows only exit status and indicates that the Windows error
 number (32 bits) cannot meaningfully be mapped to an equivalent Unix error
 number returned as the exit status (7 bits).
 .TP
+.B 35
+a transport error has occurred. This will either be in the driver (e.g. HBA
+driver) or in the interconnect between the host (initiator) and the
+device (target).  For example in SAS an expander can run out of paths and
+thus be unable to return the user data for a READ command.
+.TP
 .B 36
 no error has occurred plus the utility wants to convey a boolean value
 of false. The corresponding true value is conveyed by a 0 exit status.
diff --git a/include/sg_lib.h b/include/sg_lib.h
index 857f0d1c..35b44d69 100644
--- a/include/sg_lib.h
+++ b/include/sg_lib.h
@@ -472,6 +472,7 @@ bool sg_exit2str(int exit_status, bool longer, int b_len, char * b);
 #define SG_LIB_CAT_MISCOMPARE 14 /* sense key, probably verify
                                   *       [sk,asc,ascq: 0xe,*,*] */
 #define SG_LIB_FILE_ERROR 15    /* device or other file problem */
+/* for 17 and 18, see below */
 #define SG_LIB_CAT_NO_SENSE 20  /* sense data with key of "no sense"
                                  *       [sk,asc,ascq: 0x0,*,*] */
 #define SG_LIB_CAT_RECOVERED 21 /* Successful command after recovered err
@@ -490,8 +491,10 @@ bool sg_exit2str(int exit_status, bool longer, int b_len, char * b);
 #define SG_LIB_CAT_TASK_ABORTED 29 /* SCSI status, this command aborted by? */
 #define SG_LIB_CONTRADICT 31    /* error involving two or more cl options */
 #define SG_LIB_LOGIC_ERROR 32   /* unexpected situation in code */
+/* for 33 see SG_LIB_CAT_TIMEOUT below */
 #define SG_LIB_WINDOWS_ERR 34   /* Windows error number don't fit in 7 bits so
                                  * map to a single value for exit statuses */
+#define SG_LIB_TRANSPORT_ERROR 35	/* driver or interconnect */
 #define SG_LIB_OK_FALSE 36      /* no error, reporting false (cf. no error,
                                  * reporting true is SG_LIB_OK_TRUE(0) ) */
 #define SG_LIB_CAT_PROTECTION 40 /* subset of aborted command (for PI, DIF)
diff --git a/include/sg_lib_data.h b/include/sg_lib_data.h
index 2f142a22..01c132ea 100644
--- a/include/sg_lib_data.h
+++ b/include/sg_lib_data.h
@@ -120,6 +120,7 @@ extern struct sg_lib_value_name_t sg_lib_zoning_in_arr[];
 extern struct sg_lib_value_name_t sg_lib_read_attr_arr[];
 extern struct sg_lib_value_name_t sg_lib_read_pos_arr[];
 extern struct sg_lib_asc_ascq_range_t sg_lib_asc_ascq_range[];
+extern struct sg_lib_simple_value_name_t sg_lib_sstatus_str_arr[];
 extern struct sg_lib_asc_ascq_t sg_lib_asc_ascq[];
 extern struct sg_lib_value_name_t sg_lib_scsi_feature_sets[];
 extern const char * sg_lib_sense_key_desc[];
diff --git a/lib/sg_cmds_basic.c b/lib/sg_cmds_basic.c
index 899caae1..844018c3 100644
--- a/lib/sg_cmds_basic.c
+++ b/lib/sg_cmds_basic.c
@@ -42,7 +42,7 @@
 #endif
 
 
-static const char * const version_str = "1.98 20210601";
+static const char * const version_str = "1.99 20210830";
 
 
 #define SENSE_BUFF_LEN 64       /* Arbitrary, could be larger */
@@ -434,9 +434,12 @@ sg_ll_inquiry_com(struct sg_pt_base * ptvp, int sg_fd, bool cmddt, bool evpd,
     resid = get_scsi_pt_resid(ptvp);
     if (residp)
         *residp = resid;
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -653,9 +656,12 @@ sg_ll_test_unit_ready_com(struct sg_pt_base * ptvp, int sg_fd, int pack_id,
     set_scsi_pt_packet_id(ptvp, pack_id);
     res = do_scsi_pt(ptvp, -1, DEF_PT_TIMEOUT, verbose);
     ret = sg_cmds_process_resp(ptvp, tur_s, res, noisy, verbose, &sense_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         if (progress) {
             int slen = get_scsi_pt_sense_len(ptvp);
 
@@ -768,9 +774,12 @@ sg_ll_request_sense_com(struct sg_pt_base * ptvp, int sg_fd, bool desc,
     set_scsi_pt_data_in(ptvp, (uint8_t *)resp, mx_resp_len);
     res = do_scsi_pt(ptvp, -1, DEF_PT_TIMEOUT, verbose);
     ret = sg_cmds_process_resp(ptvp, rq_s, res, noisy, verbose, &sense_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -860,9 +869,12 @@ sg_ll_report_luns_com(struct sg_pt_base * ptvp, int sg_fd, int select_report,
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, verbose);
     ret = sg_cmds_process_resp(ptvp, report_luns_s, res, noisy, verbose,
                                &sense_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
diff --git a/lib/sg_cmds_basic2.c b/lib/sg_cmds_basic2.c
index ba06920e..06bbda62 100644
--- a/lib/sg_cmds_basic2.c
+++ b/lib/sg_cmds_basic2.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999-2020 Douglas Gilbert.
+ * Copyright (c) 1999-2021 Douglas Gilbert.
  * All rights reserved.
  * Use of this source code is governed by a BSD-style
  * license that can be found in the BSD_LICENSE file.
@@ -121,9 +121,12 @@ sg_ll_sync_cache_10(int sg_fd, bool sync_nv, bool immed, int group,
     set_scsi_pt_sense(ptvp, sense_b, sizeof(sense_b));
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, verbose);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, verbose, &sense_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -174,9 +177,12 @@ sg_ll_readcap_16(int sg_fd, bool pmi, uint64_t llba, void * resp,
     set_scsi_pt_data_in(ptvp, (uint8_t *)resp, mx_resp_len);
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, verbose);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, verbose, &sense_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -224,9 +230,12 @@ sg_ll_readcap_10(int sg_fd, bool pmi, unsigned int lba, void * resp,
     set_scsi_pt_data_in(ptvp, (uint8_t *)resp, mx_resp_len);
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, verbose);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, verbose, &sense_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -279,9 +288,12 @@ sg_ll_mode_sense6(int sg_fd, bool dbd, int pc, int pg_code, int sub_pg_code,
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, verbose);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, verbose, &sense_cat);
     resid = get_scsi_pt_resid(ptvp);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -379,9 +391,12 @@ sg_ll_mode_sense10_v2(int sg_fd, bool llbaa, bool dbd, int pc, int pg_code,
     resid = get_scsi_pt_resid(ptvp);
     if (residp)
         *residp = resid;
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -463,9 +478,12 @@ sg_ll_mode_select6_v2(int sg_fd, bool pf, bool rtd, bool sp, void * paramp,
     set_scsi_pt_data_out(ptvp, (uint8_t *)paramp, param_len);
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, verbose);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, verbose, &sense_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -531,9 +549,12 @@ sg_ll_mode_select10_v2(int sg_fd, bool pf, bool rtd, bool sp, void * paramp,
     set_scsi_pt_data_out(ptvp, (uint8_t *)paramp, param_len);
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, verbose);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, verbose, &sense_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -829,9 +850,12 @@ sg_ll_log_sense_v2(int sg_fd, bool ppc, bool sp, int pc, int pg_code,
     resid = get_scsi_pt_resid(ptvp);
     if (residp)
         *residp = resid;
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -908,9 +932,12 @@ sg_ll_log_select(int sg_fd, bool pcr, bool sp, int pc, int pg_code,
     set_scsi_pt_data_out(ptvp, paramp, param_len);
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, verbose);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, verbose, &sense_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -985,9 +1012,12 @@ sg_ll_start_stop_unit_com(struct sg_pt_base * ptvp, int sg_fd, bool immed,
     }
     res = do_scsi_pt(ptvp, -1, START_PT_TIMEOUT, verbose);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, verbose, &sense_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -1065,9 +1095,12 @@ sg_ll_prevent_allow(int sg_fd, int prevent, bool noisy, int verbose)
     set_scsi_pt_sense(ptvp, sense_b, sizeof(sense_b));
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, verbose);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, verbose, &sense_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
diff --git a/lib/sg_cmds_extra.c b/lib/sg_cmds_extra.c
index e55e8075..cbcc8444 100644
--- a/lib/sg_cmds_extra.c
+++ b/lib/sg_cmds_extra.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999-2020 Douglas Gilbert.
+ * Copyright (c) 1999-2021 Douglas Gilbert.
  * All rights reserved.
  * Use of this source code is governed by a BSD-style
  * license that can be found in the BSD_LICENSE file.
@@ -150,9 +150,12 @@ sg_ll_get_lba_status16(int sg_fd, uint64_t start_llba, uint8_t rt,
     set_scsi_pt_data_in(ptvp, (uint8_t *)resp, alloc_len);
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, vb);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, vb, &s_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (s_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -226,9 +229,12 @@ sg_ll_get_lba_status32(int sg_fd, uint64_t start_llba, uint32_t scan_len,
     set_scsi_pt_data_in(ptvp, (uint8_t *)resp, alloc_len);
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, vb);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, vb, &s_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (s_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -296,9 +302,12 @@ sg_ll_report_tgt_prt_grp2(int sg_fd, void * resp, int mx_resp_len,
     set_scsi_pt_data_in(ptvp, (uint8_t *)resp, mx_resp_len);
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, vb);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, vb, &s_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (s_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -360,9 +369,12 @@ sg_ll_set_tgt_prt_grp(int sg_fd, void * paramp, int param_len, bool noisy,
     set_scsi_pt_data_out(ptvp, (uint8_t *)paramp, param_len);
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, vb);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, vb, &s_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (s_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -412,9 +424,12 @@ sg_ll_report_referrals(int sg_fd, uint64_t start_llba, bool one_seg,
     set_scsi_pt_data_in(ptvp, (uint8_t *)resp, mx_resp_len);
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, vb);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, vb, &s_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (s_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -512,9 +527,12 @@ sg_ll_send_diag_com(struct sg_pt_base * ptvp, int sg_fd, int st_code,
     set_scsi_pt_data_out(ptvp, (uint8_t *)paramp, param_len);
     res = do_scsi_pt(ptvp, -1, tmout, vb);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, vb, &s_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (s_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -616,9 +634,12 @@ sg_ll_receive_diag_com(struct sg_pt_base * ptvp, int sg_fd, bool pcv,
     resid = get_scsi_pt_resid(ptvp);
     if (residp)
         *residp = resid;
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (s_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -722,9 +743,12 @@ sg_ll_read_defect10(int sg_fd, bool req_plist, bool req_glist, int dl_format,
     set_scsi_pt_data_in(ptvp, (uint8_t *)resp, mx_resp_len);
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, vb);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, vb, &s_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (s_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -782,9 +806,12 @@ sg_ll_read_media_serial_num(int sg_fd, void * resp, int mx_resp_len,
     set_scsi_pt_data_in(ptvp, (uint8_t *)resp, mx_resp_len);
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, vb);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, vb, &s_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (s_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -845,9 +872,12 @@ sg_ll_report_id_info(int sg_fd, int itype, void * resp, int max_resp_len,
     set_scsi_pt_data_in(ptvp, (uint8_t *)resp, max_resp_len);
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, vb);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, vb, &s_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (s_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -911,9 +941,12 @@ sg_ll_set_id_info(int sg_fd, int itype, void * paramp, int param_len,
     set_scsi_pt_data_out(ptvp, (uint8_t *)paramp, param_len);
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, vb);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, vb, &s_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (s_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -1004,9 +1037,12 @@ sg_ll_format_unit_v2(int sg_fd, int fmtpinfo, bool longlist, bool fmtdata,
     set_scsi_pt_data_out(ptvp, (uint8_t *)paramp, param_len);
     res = do_scsi_pt(ptvp, sg_fd, tmout, vb);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, vb, &s_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (s_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -1059,9 +1095,12 @@ sg_ll_reassign_blocks(int sg_fd, bool longlba, bool longlist, void * paramp,
     set_scsi_pt_data_out(ptvp, (uint8_t *)paramp, param_len);
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, vb);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, vb, &s_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (s_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -1111,9 +1150,12 @@ sg_ll_persistent_reserve_in(int sg_fd, int rq_servact, void * resp,
     set_scsi_pt_data_in(ptvp, (uint8_t *)resp, mx_resp_len);
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, vb);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, vb, &s_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (s_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -1180,9 +1222,12 @@ sg_ll_persistent_reserve_out(int sg_fd, int rq_servact, int rq_scope,
     set_scsi_pt_data_out(ptvp, (uint8_t *)paramp, param_len);
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, vb);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, vb, &s_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (s_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -1256,9 +1301,12 @@ sg_ll_read_long10(int sg_fd, bool pblock, bool correct, unsigned int lba,
     set_scsi_pt_data_in(ptvp, (uint8_t *)resp, xfer_len);
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, vb);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, vb, &s_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (s_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -1346,9 +1394,12 @@ sg_ll_read_long16(int sg_fd, bool pblock, bool correct, uint64_t llba,
     set_scsi_pt_data_in(ptvp, (uint8_t *)resp, xfer_len);
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, vb);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, vb, &s_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (s_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -1437,9 +1488,12 @@ sg_ll_write_long10(int sg_fd, bool cor_dis, bool wr_uncor, bool pblock,
     set_scsi_pt_data_out(ptvp, (uint8_t *)data_out, xfer_len);
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, vb);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, vb, &s_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (s_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -1517,9 +1571,12 @@ sg_ll_write_long16(int sg_fd, bool cor_dis, bool wr_uncor, bool pblock,
     set_scsi_pt_data_out(ptvp, (uint8_t *)data_out, xfer_len);
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, vb);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, vb, &s_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (s_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -1602,9 +1659,12 @@ sg_ll_verify10(int sg_fd, int vrprotect, bool dpo, int bytchk,
         set_scsi_pt_data_out(ptvp, (uint8_t *)data_out, data_out_len);
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, vb);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, vb, &s_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (s_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -1681,9 +1741,12 @@ sg_ll_verify16(int sg_fd, int vrprotect, bool dpo, int bytchk, uint64_t llba,
         set_scsi_pt_data_out(ptvp, (uint8_t *)data_out, data_out_len);
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, vb);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, vb, &s_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (s_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -1921,9 +1984,12 @@ sg_ll_read_buffer(int sg_fd, int mode, int buffer_id, int buffer_offset,
     set_scsi_pt_data_in(ptvp, (uint8_t *)resp, mx_resp_len);
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, vb);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, vb, &s_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (s_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -1994,9 +2060,12 @@ sg_ll_write_buffer(int sg_fd, int mode, int buffer_id, int buffer_offset,
     set_scsi_pt_data_out(ptvp, (uint8_t *)paramp, param_len);
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, vb);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, vb, &s_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (s_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -2071,9 +2140,12 @@ sg_ll_write_buffer_v2(int sg_fd, int mode, int m_specific, int buffer_id,
     set_scsi_pt_data_out(ptvp, (uint8_t *)paramp, param_len);
     res = do_scsi_pt(ptvp, sg_fd, timeout_secs, vb);
     ret = sg_cmds_process_resp(ptvp, "Write buffer", res, noisy, vb, &s_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (s_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -2137,9 +2209,12 @@ sg_ll_unmap_v2(int sg_fd, bool anchor, int group_num, int timeout_secs,
     set_scsi_pt_data_out(ptvp, (uint8_t *)paramp, param_len);
     res = do_scsi_pt(ptvp, sg_fd, tmout, vb);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, vb, &s_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (s_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -2183,9 +2258,12 @@ sg_ll_read_block_limits(int sg_fd, void * resp, int mx_resp_len,
     set_scsi_pt_data_in(ptvp, (uint8_t *)resp, mx_resp_len);
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, vb);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, vb, &s_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (s_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -2250,9 +2328,12 @@ sg_ll_receive_copy_results(int sg_fd, int sa, int list_id, void * resp,
     set_scsi_pt_data_in(ptvp, (uint8_t *)resp, mx_resp_len);
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, vb);
     ret = sg_cmds_process_resp(ptvp, b, res, noisy, vb, &s_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (s_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -2309,9 +2390,12 @@ sg_ll_extended_copy(int sg_fd, void * paramp, int param_len, bool noisy,
     set_scsi_pt_data_out(ptvp, (uint8_t *)paramp, param_len);
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, vb);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, vb, &s_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (s_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -2386,9 +2470,12 @@ sg_ll_3party_copy_out(int sg_fd, int sa, unsigned int list_id, int group_num,
     set_scsi_pt_data_out(ptvp, (uint8_t *)paramp, param_len);
     res = do_scsi_pt(ptvp, sg_fd, tmout, vb);
     ret = sg_cmds_process_resp(ptvp, cname, res, noisy, vb, &s_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (s_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -2490,9 +2577,12 @@ sg_ll_pre_fetch_x(int sg_fd, bool do_seek10, bool cdb16, bool immed,
         }
     }
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, vb, &s_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (s_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
diff --git a/lib/sg_cmds_mmc.c b/lib/sg_cmds_mmc.c
index c1dabd74..e3629559 100644
--- a/lib/sg_cmds_mmc.c
+++ b/lib/sg_cmds_mmc.c
@@ -84,9 +84,12 @@ sg_ll_set_cd_speed(int sg_fd, int rot_control, int drv_read_speed,
     set_scsi_pt_sense(ptvp, sense_b, sizeof(sense_b));
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, verbose);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, verbose, &sense_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_NOT_READY:
         case SG_LIB_CAT_UNIT_ATTENTION:
@@ -157,9 +160,12 @@ sg_ll_get_config(int sg_fd, int rt, int starting, void * resp,
     set_scsi_pt_data_in(ptvp, (uint8_t *)resp, mx_resp_len);
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, verbose);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, verbose, &sense_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_INVALID_OP:
         case SG_LIB_CAT_ILLEGAL_REQ:
@@ -250,9 +256,12 @@ sg_ll_get_performance(int sg_fd, int data_type, unsigned int starting_lba,
     set_scsi_pt_data_in(ptvp, (uint8_t *)resp, mx_resp_len);
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, verbose);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, verbose, &sense_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_INVALID_OP:
         case SG_LIB_CAT_ILLEGAL_REQ:
@@ -332,9 +341,12 @@ sg_ll_set_streaming(int sg_fd, int type, void * paramp, int param_len,
     set_scsi_pt_data_out(ptvp, (uint8_t *)paramp, param_len);
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, verbose);
     ret = sg_cmds_process_resp(ptvp, cdb_s, res, noisy, verbose, &sense_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_NOT_READY:
         case SG_LIB_CAT_INVALID_OP:
diff --git a/lib/sg_io_linux.c b/lib/sg_io_linux.c
index 25ccb47d..9bd4b7eb 100644
--- a/lib/sg_io_linux.c
+++ b/lib/sg_io_linux.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999-2020 Douglas Gilbert.
+ * Copyright (c) 1999-2021 Douglas Gilbert.
  * All rights reserved.
  * Use of this source code is governed by a BSD-style
  * license that can be found in the BSD_LICENSE file.
@@ -24,7 +24,7 @@
 #include "sg_pr2serr.h"
 
 
-/* Version 1.11 20200401 */
+/* Version 1.12 20210830 */
 
 
 void
@@ -43,7 +43,7 @@ static const char * linux_host_bytes[] = {
     "DID_RESET", "DID_BAD_INTR", "DID_PASSTHROUGH", "DID_SOFT_ERROR",
     "DID_IMM_RETRY", "DID_REQUEUE", "DID_TRANSPORT_DISRUPTED",
     "DID_TRANSPORT_FAILFAST", "DID_TARGET_FAILURE", "DID_NEXUS_FAILURE",
-    "DID_ALLOC_FAILURE", "DID_MEDIUM_ERROR",
+    "DID_ALLOC_FAILURE", "DID_MEDIUM_ERROR", "DID_TRANSPORT_MARGINAL",
 };
 
 void
@@ -57,8 +57,9 @@ sg_print_host_status(int host_status)
         pr2ws("[%s] ", linux_host_bytes[host_status]);
 }
 
-/* DRIVER_* are Linux SCSI result (a 32 bit variable) bits 24:27 */
-
+/* DRIVER_* are Linux SCSI result (a 32 bit variable) bits 24:27 .
+ * These where made obsolete around lk 5.12.0 . Only DRIVER_SENSE [0x8] is
+ * defined in scsi/sg.h for backward comaptibility */
 static const char * linux_driver_bytes[] = {
     "DRIVER_OK", "DRIVER_BUSY", "DRIVER_SOFT", "DRIVER_MEDIA",
     "DRIVER_ERROR", "DRIVER_INVALID", "DRIVER_TIMEOUT", "DRIVER_HARD",
diff --git a/lib/sg_lib.c b/lib/sg_lib.c
index c5eeeddc..02102a1c 100644
--- a/lib/sg_lib.c
+++ b/lib/sg_lib.c
@@ -245,22 +245,6 @@ sg_print_command(const uint8_t * cdbp)
     sg_print_command_len(cdbp, 0);
 }
 
-/* SCSI Status values */
-static const struct sg_lib_simple_value_name_t sstatus_str_arr[] = {
-    {0x0,  "Good"},
-    {0x2,  "Check Condition"},
-    {0x4,  "Condition Met"},
-    {0x8,  "Busy"},
-    {0x10, "Intermediate (obsolete)"},
-    {0x14, "Intermediate-Condition Met (obsolete)"},
-    {0x18, "Reservation Conflict"},
-    {0x22, "Command terminated (obsolete)"},
-    {0x28, "Task Set Full"},
-    {0x30, "ACA Active"},
-    {0x40, "Task Aborted"},
-    {0xffff, NULL},
-};
-
 bool
 sg_scsi_status_is_good(int sstatus)
 {
@@ -299,7 +283,7 @@ sg_get_scsi_status_str(int scsi_status, int buff_len, char * buff)
         return;
     }
     scsi_status &= 0x7e; /* sanitize as much as possible */
-    for (sstatus_p = sstatus_str_arr; sstatus_p->name; ++sstatus_p) {
+    for (sstatus_p = sg_lib_sstatus_str_arr; sstatus_p->name; ++sstatus_p) {
         if (scsi_status == sstatus_p->value)
             break;
     }
diff --git a/lib/sg_lib_data.c b/lib/sg_lib_data.c
index ff89ac79..a132d1cb 100644
--- a/lib/sg_lib_data.c
+++ b/lib/sg_lib_data.c
@@ -19,7 +19,7 @@
 #include "sg_lib_data.h"
 
 
-const char * sg_lib_version_str = "2.81 20210526";
+const char * sg_lib_version_str = "2.82 20210830";
 /* spc6r05, sbc5r01, zbc2r10 */
 
 
@@ -34,6 +34,22 @@ int sg_lib_pdt_decay_arr[32] = {
     0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, PDT_WLUN, PDT_UNKNOWN
 };
 
+/* SCSI Status values */
+struct sg_lib_simple_value_name_t sg_lib_sstatus_str_arr[] = {
+    {0x0,  "Good"},
+    {0x2,  "Check Condition"},
+    {0x4,  "Condition Met"},
+    {0x8,  "Busy"},
+    {0x10, "Intermediate (obsolete)"},
+    {0x14, "Intermediate-Condition Met (obsolete)"},
+    {0x18, "Reservation Conflict"},
+    {0x22, "Command terminated (obsolete)"},
+    {0x28, "Task Set Full"},
+    {0x30, "ACA Active"},
+    {0x40, "Task Aborted"},
+    {0xffff, NULL},
+};
+
 #ifdef SG_SCSI_STRINGS
 struct sg_lib_value_name_t sg_lib_normal_opcodes[] = {
     {0, 0, "Test Unit Ready"},
@@ -1805,6 +1821,8 @@ struct sg_value_2names_t sg_exit_str_arr[] = {
     {31, "Contradict", "command line options contradict or select bad mode"},
     {32, "Logic error", "unexpected situation, contact author"},
     {33, "SCSI command timeout", NULL},         /* OS timed out command */
+    {34, "Windows error number", "doesn't fit in 7 bits"},
+    {35, "Transport error", "driver or interconnect error"}, 
     {36, "No errors (false)", NULL},
     {40, "Aborted command, protection error", NULL},
     {41, "Aborted command, protection error with Info field", NULL},
diff --git a/lib/sg_pt_linux.c b/lib/sg_pt_linux.c
index cd9083d0..c6fb9755 100644
--- a/lib/sg_pt_linux.c
+++ b/lib/sg_pt_linux.c
@@ -7,7 +7,7 @@
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
-/* sg_pt_linux version 1.52 20210423 */
+/* sg_pt_linux version 1.53 20210830 */
 
 
 #include <stdio.h>
@@ -71,8 +71,11 @@ static const char * linux_host_bytes[] = {
     "DID_NEXUS_FAILURE (reservation conflict)",
     "DID_ALLOC_FAILURE",
     "DID_MEDIUM_ERROR",
+    "DID_TRANSPORT_MARGINAL",	/*0x14 */
 };
 
+/* These where made obsolete around lk 5.12.0 . Only DRIVER_SENSE [0x8] is
+ * defined in scsi/sg.h for backward comaptibility */
 static const char * linux_driver_bytes[] = {
     "DRIVER_OK", "DRIVER_BUSY", "DRIVER_SOFT", "DRIVER_MEDIA",
     "DRIVER_ERROR", "DRIVER_INVALID", "DRIVER_TIMEOUT", "DRIVER_HARD",
diff --git a/sg3_utils.spec b/sg3_utils.spec
index 5e5dbc69..346d7e01 100644
--- a/sg3_utils.spec
+++ b/sg3_utils.spec
@@ -84,7 +84,7 @@ fi
 %{_libdir}/*.la
 
 %changelog
-* Mon Aug 16 2021 - dgilbert at interlog dot com
+* Mon Aug 30 2021 - dgilbert at interlog dot com
 - track t10 changes
   * sg3_utils-1.47
 
diff --git a/src/sg_bg_ctl.c b/src/sg_bg_ctl.c
index d7df6587..a1ca3f23 100644
--- a/src/sg_bg_ctl.c
+++ b/src/sg_bg_ctl.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016-2019 Douglas Gilbert.
+ * Copyright (c) 2016-2021 Douglas Gilbert.
  * All rights reserved.
  * Use of this source code is governed by a BSD-style
  * license that can be found in the BSD_LICENSE file.
@@ -35,7 +35,7 @@
  * device. Based on sbc4r10.pdf .
  */
 
-static const char * version_str = "1.11 20191220";
+static const char * version_str = "1.12 20210830";
 
 #define BACKGROUND_CONTROL_SA 0x15
 
@@ -118,9 +118,12 @@ sg_ll_background_control(int sg_fd, unsigned int bo_ctl, unsigned int bo_time,
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, verbose);
     ret = sg_cmds_process_resp(ptvp, cmd_name, res, noisy, verbose,
                                &sense_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
diff --git a/src/sg_compare_and_write.c b/src/sg_compare_and_write.c
index adf27779..e3762021 100644
--- a/src/sg_compare_and_write.c
+++ b/src/sg_compare_and_write.c
@@ -1,5 +1,5 @@
 /*
-*  Copyright (c) 2012-2020, Kaminario Technologies LTD
+*  Copyright (c) 2012-2021, Kaminario Technologies LTD
 *  All rights reserved.
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions are met:
@@ -56,7 +56,7 @@
 #include "sg_unaligned.h"
 #include "sg_pr2serr.h"
 
-static const char * version_str = "1.29 20200509";
+static const char * version_str = "1.30 20210830";
 
 #define DEF_BLOCK_SIZE 512
 #define DEF_NUM_BLOCKS (1)
@@ -292,8 +292,8 @@ parse_args(int argc, char* argv[], struct opts_t * op)
                         goto out_err;
                 }
         }
-	if (op->version_given && (! op->verbose_given))
-		return 0;
+        if (op->version_given && (! op->verbose_given))
+                return 0;
         if (NULL == op->device_name) {
                 pr2serr("missing device name!\n");
                 goto out_err;
@@ -385,9 +385,12 @@ sg_ll_compare_and_write(int sg_fd, uint8_t * buff, int blocks,
         res = do_scsi_pt(ptvp, sg_fd, DEF_TIMEOUT_SECS, verbose);
         ret = sg_cmds_process_resp(ptvp, "COMPARE AND WRITE", res,
                                    noisy, verbose, &sense_cat);
-        if (-1 == ret)
+        if (-1 == ret) {
+            if (get_scsi_pt_transport_err(ptvp))
+                ret = SG_LIB_TRANSPORT_ERROR;
+            else
                 ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-        else if (-2 == ret) {
+        } else if (-2 == ret) {
                 switch (sense_cat) {
                 case SG_LIB_CAT_RECOVERED:
                 case SG_LIB_CAT_NO_SENSE:
diff --git a/src/sg_format.c b/src/sg_format.c
index e629104e..0d9b3185 100644
--- a/src/sg_format.c
+++ b/src/sg_format.c
@@ -40,7 +40,7 @@
 #include "sg_pr2serr.h"
 #include "sg_pt.h"
 
-static const char * version_str = "1.62 20201223";
+static const char * version_str = "1.63 20210830";
 
 
 #define RW_ERROR_RECOVERY_PAGE 1  /* can give alternate with --mode=MP */
@@ -308,9 +308,12 @@ sg_ll_format_medium(int sg_fd, bool verify, bool immed, int format,
         res = do_scsi_pt(ptvp, sg_fd, timeout, verbose);
         ret = sg_cmds_process_resp(ptvp, fm_s, res, noisy, verbose,
                                    &sense_cat);
-        if (-1 == ret)
+        if (-1 == ret) {
+            if (get_scsi_pt_transport_err(ptvp))
+                ret = SG_LIB_TRANSPORT_ERROR;
+            else
                 ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-        else if (-2 == ret) {
+        } else if (-2 == ret) {
                 switch (sense_cat) {
                 case SG_LIB_CAT_RECOVERED:
                 case SG_LIB_CAT_NO_SENSE:
@@ -367,9 +370,12 @@ sg_ll_format_with_preset(int sg_fd, bool immed, bool fmtmaxlba,
         res = do_scsi_pt(ptvp, sg_fd, timeout, verbose);
         ret = sg_cmds_process_resp(ptvp, fwp_s, res, noisy, verbose,
                                    &sense_cat);
-        if (-1 == ret)
+        if (-1 == ret) {
+            if (get_scsi_pt_transport_err(ptvp))
+                ret = SG_LIB_TRANSPORT_ERROR;
+            else
                 ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-        else if (-2 == ret) {
+        } else if (-2 == ret) {
                 switch (sense_cat) {
                 case SG_LIB_CAT_RECOVERED:
                 case SG_LIB_CAT_NO_SENSE:
diff --git a/src/sg_get_elem_status.c b/src/sg_get_elem_status.c
index 389a3792..94f1813e 100644
--- a/src/sg_get_elem_status.c
+++ b/src/sg_get_elem_status.c
@@ -37,7 +37,7 @@
  * given SCSI device.
  */
 
-static const char * version_str = "1.04 20210803";      /* sbc4r19 */
+static const char * version_str = "1.05 20210830";      /* sbc4r19 */
 
 
 #ifndef UINT32_MAX
@@ -174,9 +174,12 @@ sg_ll_get_phy_elem_status(int sg_fd, uint32_t starting_elem, uint8_t filter,
     res = do_scsi_pt(ptvp, -1, DEF_PT_TIMEOUT, verbose);
     ret = sg_cmds_process_resp(ptvp, cmd_name, res, noisy, verbose,
                                &sense_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
diff --git a/src/sg_opcodes.c b/src/sg_opcodes.c
index 4abe9f17..ffa7823c 100644
--- a/src/sg_opcodes.c
+++ b/src/sg_opcodes.c
@@ -33,7 +33,7 @@
 
 #include "sg_pt.h"
 
-static const char * version_str = "0.70 20210610";    /* spc6r05 */
+static const char * version_str = "0.71 20210830";    /* spc6r05 */
 
 
 #define SENSE_BUFF_LEN 64       /* Arbitrary, could be larger */
@@ -222,9 +222,12 @@ do_rsoc(struct sg_pt_base * ptvp, bool rctd, int rep_opts, int rq_opcode,
     set_scsi_pt_data_in(ptvp, (uint8_t *)resp, mx_resp_len);
     res = do_scsi_pt(ptvp, -1, DEF_TIMEOUT_SECS, verbose);
     ret = sg_cmds_process_resp(ptvp, rsoc_s, res, noisy, verbose, &sense_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -278,9 +281,12 @@ do_rstmf(struct sg_pt_base * ptvp, bool repd, void * resp, int mx_resp_len,
     res = do_scsi_pt(ptvp, -1, DEF_TIMEOUT_SECS, verbose);
     ret = sg_cmds_process_resp(ptvp, rstmf_s, res, noisy, verbose,
                                &sense_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
diff --git a/src/sg_read_attr.c b/src/sg_read_attr.c
index 3f5d6528..87124d3c 100644
--- a/src/sg_read_attr.c
+++ b/src/sg_read_attr.c
@@ -39,7 +39,7 @@
  * and decodes the response. Based on spc5r08.pdf
  */
 
-static const char * version_str = "1.14 20210610";
+static const char * version_str = "1.15 20210830";
 
 #define MAX_RATTR_BUFF_LEN (1024 * 1024)
 #define DEF_RATTR_BUFF_LEN (1024 * 8)
@@ -283,9 +283,12 @@ sg_ll_read_attr(int sg_fd, void * resp, int * residp, bool noisy,
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, op->verbose);
     ret = sg_cmds_process_resp(ptvp, "read attribute", res, noisy,
                                op->verbose, &sense_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
diff --git a/src/sg_read_buffer.c b/src/sg_read_buffer.c
index 33aa1673..e3dae423 100644
--- a/src/sg_read_buffer.c
+++ b/src/sg_read_buffer.c
@@ -39,7 +39,7 @@
  * device.
  */
 
-static const char * version_str = "1.31 20210608";      /* spc6r05 */
+static const char * version_str = "1.32 20210830";      /* spc6r05 */
 
 
 #ifndef SG_READ_BUFFER_10_CMD
@@ -194,9 +194,12 @@ sg_ll_read_buffer_10(int sg_fd, int rb_mode, int rb_mode_sp, int rb_id,
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, verbose);
     ret = sg_cmds_process_resp(ptvp, "Read buffer(10)", res, noisy, verbose,
                                &sense_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -259,9 +262,12 @@ sg_ll_read_buffer_16(int sg_fd, int rb_mode, int rb_mode_sp, int rb_id,
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, verbose);
     ret = sg_cmds_process_resp(ptvp, "Read buffer(16)", res, noisy, verbose,
                                &sense_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
diff --git a/src/sg_rep_pip.c b/src/sg_rep_pip.c
index 56d12e53..f800d81a 100644
--- a/src/sg_rep_pip.c
+++ b/src/sg_rep_pip.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014-2020 Douglas Gilbert.
+ * Copyright (c) 2014-2021 Douglas Gilbert.
  * All rights reserved.
  * Use of this source code is governed by a BSD-style
  * license that can be found in the BSD_LICENSE file.
@@ -39,7 +39,7 @@
  * sbc4r21.pdf
  */
 
-static const char * version_str = "1.01 20200605";
+static const char * version_str = "1.02 20210830";
 
 #define MAX_RPIP_BUFF_LEN (1024 * 1024)
 #define DEF_RPIP_BUFF_LEN 512
@@ -123,9 +123,12 @@ sg_ll_report_pip(int sg_fd, void * resp, int mx_resp_len, int * residp,
     set_scsi_pt_data_in(ptvp, (uint8_t *)resp, mx_resp_len);
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, verbose);
     ret = sg_cmds_process_resp(ptvp, rpip_s, res, noisy, verbose, &sense_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
diff --git a/src/sg_rep_zones.c b/src/sg_rep_zones.c
index 4c601f00..e968d295 100644
--- a/src/sg_rep_zones.c
+++ b/src/sg_rep_zones.c
@@ -39,7 +39,7 @@
  * Based on zbc2r10.pdf
  */
 
-static const char * version_str = "1.26 20210726";
+static const char * version_str = "1.27 20210830";
 
 #define MAX_RZONES_BUFF_LEN (1024 * 1024)
 #define DEF_RZONES_BUFF_LEN (1024 * 8)
@@ -216,9 +216,12 @@ sg_ll_report_zzz(int sg_fd, int serv_act, uint64_t zs_lba, bool partial,
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, vb);
     ret = sg_cmds_process_resp(ptvp, "report zone/domain/realm", res, noisy,
                                vb, &sense_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
diff --git a/src/sg_requests.c b/src/sg_requests.c
index f27c60d6..99e42dd9 100644
--- a/src/sg_requests.c
+++ b/src/sg_requests.c
@@ -34,7 +34,7 @@
  * This program issues the SCSI command REQUEST SENSE to the given SCSI device.
  */
 
-static const char * version_str = "1.36 20210610";
+static const char * version_str = "1.37 20210830";
 
 #define MAX_REQS_RESP_LEN 255
 #define DEF_REQS_RESP_LEN 252
@@ -331,7 +331,10 @@ main(int argc, char * argv[])
                                          verbose, &sense_cat);
             }
             if (-1 == n) {
-                ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+                if (get_scsi_pt_transport_err(ptvp))
+                    ret = SG_LIB_TRANSPORT_ERROR;
+                else
+                    ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
                 goto finish;
             } else if (-2 == n) {
                 switch (sense_cat) {
@@ -424,7 +427,10 @@ main(int argc, char * argv[])
                                      verbose, &sense_cat);
         }
         if (-1 == n) {
-            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+            if (get_scsi_pt_transport_err(ptvp))
+                ret = SG_LIB_TRANSPORT_ERROR;
+            else
+                ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
             goto finish;
         } else if (-2 == n) {
             switch (sense_cat) {
diff --git a/src/sg_reset_wp.c b/src/sg_reset_wp.c
index 7f265490..3a99a722 100644
--- a/src/sg_reset_wp.c
+++ b/src/sg_reset_wp.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014-2019 Douglas Gilbert.
+ * Copyright (c) 2014-2021 Douglas Gilbert.
  * All rights reserved.
  * Use of this source code is governed by a BSD-style
  * license that can be found in the BSD_LICENSE file.
@@ -37,7 +37,7 @@
  * device. Based on zbc-r04c.pdf .
  */
 
-static const char * version_str = "1.14 20191220";
+static const char * version_str = "1.15 20210830";
 
 #define SG_ZONING_OUT_CMDLEN 16
 #define RESET_WRITE_POINTER_SA 0x4
@@ -113,9 +113,12 @@ sg_ll_reset_write_pointer(int sg_fd, uint64_t zid, uint16_t zc, bool all,
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, verbose);
     ret = sg_cmds_process_resp(ptvp, "reset write pointer", res, noisy,
                                verbose, &sense_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
diff --git a/src/sg_sanitize.c b/src/sg_sanitize.c
index 04a8ee90..6865e463 100644
--- a/src/sg_sanitize.c
+++ b/src/sg_sanitize.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011-2020 Douglas Gilbert.
+ * Copyright (c) 2011-2021 Douglas Gilbert.
  * All rights reserved.
  * Use of this source code is governed by a BSD-style
  * license that can be found in the BSD_LICENSE file.
@@ -33,7 +33,7 @@
 #include "sg_unaligned.h"
 #include "sg_pr2serr.h"
 
-static const char * version_str = "1.15 20201223";
+static const char * version_str = "1.16 20210830";
 
 /* Not all environments support the Unix sleep() */
 #if defined(MSC_VER) || defined(__MINGW32__)
@@ -245,9 +245,12 @@ do_sanitize(int sg_fd, const struct opts_t * op, const void * param_lstp,
     res = do_scsi_pt(ptvp, sg_fd, timeout, op->verbose);
     ret = sg_cmds_process_resp(ptvp, "Sanitize", res, true /*noisy */,
                                op->verbose, &sense_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
diff --git a/src/sg_stream_ctl.c b/src/sg_stream_ctl.c
index 61bb40f8..3f1ff844 100644
--- a/src/sg_stream_ctl.c
+++ b/src/sg_stream_ctl.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018-2020 Douglas Gilbert.
+ * Copyright (c) 2018-2021 Douglas Gilbert.
  * All rights reserved.
  * Use of this source code is governed by a BSD-style
  * license that can be found in the BSD_LICENSE file.
@@ -35,7 +35,7 @@
  * to the given SCSI device. Based on sbc4r15.pdf .
  */
 
-static const char * version_str = "1.09 20200724";
+static const char * version_str = "1.10 20210830";
 
 #define STREAM_CONTROL_SA 0x14
 #define GET_STREAM_STATUS_SA 0x16
@@ -142,9 +142,12 @@ sg_ll_get_stream_status(int sg_fd, uint16_t s_str_id, uint8_t * resp,
     res = do_scsi_pt(ptvp, -1, DEF_PT_TIMEOUT, verbose);
     ret = sg_cmds_process_resp(ptvp, cmd_name, res, noisy, verbose,
                                &sense_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -209,9 +212,12 @@ sg_ll_stream_control(int sg_fd, uint32_t str_ctl, uint16_t str_id,
     res = do_scsi_pt(ptvp, -1, DEF_PT_TIMEOUT, verbose);
     ret = sg_cmds_process_resp(ptvp, cmd_name, res, noisy, verbose,
                                &sense_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
diff --git a/src/sg_sync.c b/src/sg_sync.c
index a40c1970..751b25c8 100644
--- a/src/sg_sync.c
+++ b/src/sg_sync.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2004-2019 Douglas Gilbert.
+ * Copyright (c) 2004-2021 Douglas Gilbert.
  * All rights reserved.
  * Use of this source code is governed by a BSD-style
  * license that can be found in the BSD_LICENSE file.
@@ -37,7 +37,7 @@
  * (e.g. disks).
  */
 
-static const char * version_str = "1.25 20191220";
+static const char * version_str = "1.26 20210830";
 
 #define SYNCHRONIZE_CACHE16_CMD     0x91
 #define SYNCHRONIZE_CACHE16_CMDLEN  16
@@ -129,9 +129,12 @@ sg_ll_sync_cache_16(int sg_fd, bool sync_nv, bool immed, int group,
     res = do_scsi_pt(ptvp, sg_fd, to_secs, verbose);
     ret = sg_cmds_process_resp(ptvp, "synchronize cache(16)", res,
                                noisy, verbose, &sense_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
diff --git a/src/sg_timestamp.c b/src/sg_timestamp.c
index cc3d054b..58f12975 100644
--- a/src/sg_timestamp.c
+++ b/src/sg_timestamp.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015-2019 Douglas Gilbert.
+ * Copyright (c) 2015-2021 Douglas Gilbert.
  * All rights reserved.
  * Use of this source code is governed by a BSD-style
  * license that can be found in the BSD_LICENSE file.
@@ -37,7 +37,7 @@
  * to the given SCSI device. Based on spc5r07.pdf .
  */
 
-static const char * version_str = "1.14 20191220";
+static const char * version_str = "1.14 20210830";
 
 #define REP_TIMESTAMP_CMDLEN 12
 #define SET_TIMESTAMP_CMDLEN 12
@@ -220,9 +220,12 @@ sg_ll_rep_timestamp(int sg_fd, void * resp, int mx_resp_len, int * residp,
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, verbose);
     ret = sg_cmds_process_resp(ptvp, "report timestamp", res, noisy, verbose,
                                &sense_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
@@ -284,9 +287,12 @@ sg_ll_set_timestamp(int sg_fd, void * paramp, int param_len, bool noisy,
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, verbose);
     ret = sg_cmds_process_resp(ptvp, "set timestamp", res, noisy, verbose,
                                &sense_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
diff --git a/src/sg_turs.c b/src/sg_turs.c
index 9544e344..7b575911 100644
--- a/src/sg_turs.c
+++ b/src/sg_turs.c
@@ -45,7 +45,7 @@
 #include "sg_pr2serr.h"
 
 
-static const char * version_str = "3.48 20210102";
+static const char * version_str = "3.49 20210830";
 
 #define DEF_PT_TIMEOUT  60       /* 60 seconds */
 
@@ -389,7 +389,10 @@ loop_turs(struct sg_pt_base * ptvp, struct loop_res_t * resp,
             n = sg_cmds_process_resp(ptvp, "Test unit ready", rs, (0 == k),
                                      vb, &sense_cat);
             if (-1 == n) {
-                resp->ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+                if (get_scsi_pt_transport_err(ptvp))
+                    resp->ret = SG_LIB_TRANSPORT_ERROR;
+                else
+                    resp->ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
                 return k;
             } else if (-2 == n) {
                 switch (sense_cat) {
@@ -441,7 +444,7 @@ loop_turs(struct sg_pt_base * ptvp, struct loop_res_t * resp,
                     if (SG_LIB_CAT_NOT_READY == res) {
                         if (! check_for_lu_becoming(ptvp))
                             printf("device not ready\n");
-			continue;
+                        continue;
                     } else {
                         sg_get_category_sense_str(res, sizeof(b), b, vb);
                         printf("%s\n", b);
diff --git a/src/sg_write_same.c b/src/sg_write_same.c
index 23077c0a..bfbfdca7 100644
--- a/src/sg_write_same.c
+++ b/src/sg_write_same.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2009-2020 Douglas Gilbert.
+ * Copyright (c) 2009-2021 Douglas Gilbert.
  * All rights reserved.
  * Use of this source code is governed by a BSD-style
  * license that can be found in the BSD_LICENSE file.
@@ -33,7 +33,7 @@
 #include "sg_unaligned.h"
 #include "sg_pr2serr.h"
 
-static const char * version_str = "1.32 20210630";
+static const char * version_str = "1.33 20210830";
 
 
 #define ME "sg_write_same: "
@@ -276,9 +276,12 @@ do_write_same(int sg_fd, const struct opts_t * op, const void * dataoutp,
     res = do_scsi_pt(ptvp, sg_fd, op->timeout, op->verbose);
     ret = sg_cmds_process_resp(ptvp, "Write same", res, true /*noisy */,
                                op->verbose, &sense_cat);
-    if (-1 == ret)
-        ret = get_scsi_pt_os_err(ptvp);
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
diff --git a/src/sg_write_verify.c b/src/sg_write_verify.c
index 58fe9254..13030206 100644
--- a/src/sg_write_verify.c
+++ b/src/sg_write_verify.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014-2020 Douglas Gilbert
+ * Copyright (c) 2014-2021 Douglas Gilbert
  * All rights reserved.
  * Use of this source code is governed by a BSD-style
  * license that can be found in the BSD_LICENSE file.
@@ -40,7 +40,7 @@
 #include "sg_unaligned.h"
 #include "sg_pr2serr.h"
 
-static const char * version_str = "1.18 20200430";
+static const char * version_str = "1.19 20210830";
 
 
 #define ME "sg_write_verify: "
@@ -153,9 +153,12 @@ run_scsi_transaction(int sg_fd, const uint8_t *cdbp, int cdb_len,
     set_scsi_pt_data_out(ptvp, dop, do_len);
     res = do_scsi_pt(ptvp, sg_fd, timeout, verbose);
     ret = sg_cmds_process_resp(ptvp, b, res, noisy, verbose, &sense_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
diff --git a/src/sg_write_x.c b/src/sg_write_x.c
index 3b2cf5eb..3e6d1fae 100644
--- a/src/sg_write_x.c
+++ b/src/sg_write_x.c
@@ -38,7 +38,7 @@
 #include "sg_unaligned.h"
 #include "sg_pr2serr.h"
 
-static const char * version_str = "1.26 20210630";
+static const char * version_str = "1.27 20210830";
 
 /* Protection Information refers to 8 bytes of extra information usually
  * associated with each logical block and is often abbreviated to PI while
@@ -1333,9 +1333,12 @@ do_write_x(int sg_fd, const void * dataoutp, int dout_len,
     res = do_scsi_pt(ptvp, sg_fd, op->timeout, vb);
     ret = sg_cmds_process_resp(ptvp, op->cdb_name, res, true /*noisy */, vb,
                                &sense_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE:
diff --git a/src/sg_zone.c b/src/sg_zone.c
index 18a07958..f47e6f65 100644
--- a/src/sg_zone.c
+++ b/src/sg_zone.c
@@ -37,7 +37,7 @@
  * to the given SCSI device. Based on zbc-r04c.pdf .
  */
 
-static const char * version_str = "1.15 20210122";
+static const char * version_str = "1.16 20210830";
 
 #define SG_ZONING_OUT_CMDLEN 16
 #define CLOSE_ZONE_SA 0x1
@@ -70,7 +70,7 @@ static struct option long_options[] = {
 
 /* Indexed by service action */
 static const char * sa_name_arr[] = {
-    "no SA=0",			/* 0x0 */
+    "no SA=0",                  /* 0x0 */
     "Close zone",
     "Finish zone",
     "Open zone",
@@ -165,9 +165,12 @@ sg_ll_zone_out(int sg_fd, int sa, uint64_t zid, uint16_t zc, bool all,
     res = do_scsi_pt(ptvp, sg_fd, DEF_PT_TIMEOUT, verbose);
     ret = sg_cmds_process_resp(ptvp, b, res, noisy,
                                verbose, &sense_cat);
-    if (-1 == ret)
-        ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
-    else if (-2 == ret) {
+    if (-1 == ret) {
+        if (get_scsi_pt_transport_err(ptvp))
+            ret = SG_LIB_TRANSPORT_ERROR;
+        else
+            ret = sg_convert_errno(get_scsi_pt_os_err(ptvp));
+    } else if (-2 == ret) {
         switch (sense_cat) {
         case SG_LIB_CAT_RECOVERED:
         case SG_LIB_CAT_NO_SENSE: