diff --git a/scst/include/scst.h b/scst/include/scst.h
index 24a510ff6..95c7b18d9 100644
--- a/scst/include/scst.h
+++ b/scst/include/scst.h
@@ -360,11 +360,14 @@ enum scst_exec_context {
 /* Set if the cmd is aborted by other initiator */
 #define SCST_CMD_ABORTED_OTHER		1
 
+/* Set if the cmd is aborted and counted in cmd_done_wait_count */
+#define SCST_CMD_DONE_COUNTED		2
+
 /* Set if no response should be sent to the target about this cmd */
-#define SCST_CMD_NO_RESP		2
+#define SCST_CMD_NO_RESP		3
 
 /* Set if the cmd is dead and can be destroyed at any time */
-#define SCST_CMD_CAN_BE_DESTROYED	3
+#define SCST_CMD_CAN_BE_DESTROYED	4
 
 /*************************************************************
  ** Tgt_dev's async. flags (tgt_dev_flags)
@@ -386,10 +389,6 @@ enum scst_exec_context {
 
 #define SCST_TGT_DEV_CLUST_POOL			11
 
-#ifdef CONFIG_SCST_DEBUG_TM
-#define SCST_TGT_DEV_UNDER_TM_DBG		20
-#endif
-
 /*************************************************************
  ** Name of the entry in /proc
  *************************************************************/
diff --git a/scst/src/Makefile b/scst/src/Makefile
index bd9fe746f..665575420 100644
--- a/scst/src/Makefile
+++ b/scst/src/Makefile
@@ -128,7 +128,7 @@ EXTRA_CFLAGS += -DCONFIG_SCST_EXTRACHECKS
 #EXTRA_CFLAGS += -DCONFIG_SCST_TRACING
 
 EXTRA_CFLAGS += -DCONFIG_SCST_DEBUG -g
-#EXTRA_CFLAGS += -DCONFIG_SCST_DEBUG_TM -UCONFIG_SCST_TM_DBG_GO_OFFLINE
+#EXTRA_CFLAGS += -DCONFIG_SCST_DEBUG_TM -DCONFIG_SCST_TM_DBG_GO_OFFLINE
 #EXTRA_CFLAGS += -DCONFIG_SCST_DEBUG_RETRY
 #EXTRA_CFLAGS += -DCONFIG_SCST_DEBUG_OOM
 #EXTRA_CFLAGS += -DCONFIG_SCST_DEBUG_SN
diff --git a/scst/src/scst_lib.c b/scst/src/scst_lib.c
index 021d7eee2..8195a310a 100644
--- a/scst/src/scst_lib.c
+++ b/scst/src/scst_lib.c
@@ -3594,7 +3594,7 @@ static int tm_dbg_passed_cmds_count;
 static int tm_dbg_state;
 static int tm_dbg_on_state_passes;
 static DEFINE_TIMER(tm_dbg_timer, tm_dbg_timer_fn, 0, 0);
-static wait_queue_head_t *tm_dbg_p_cmd_list_waitQ;
+struct scst_tgt_dev *tm_dbg_tgt_dev;
 
 static const int tm_dbg_on_state_num_passes[] = { 5, 1, 0x7ffffff };
 
@@ -3603,29 +3603,35 @@ static void tm_dbg_init_tgt_dev(struct scst_tgt_dev *tgt_dev,
 {
 	if ((acg_dev->acg == scst_default_acg) && (acg_dev->lun == 0)) {
 		unsigned long flags;
+
+		if (tm_dbg_tgt_dev != NULL)
+			tm_dbg_deinit_tgt_dev(tm_dbg_tgt_dev);
+
 		/* Do TM debugging only for LUN 0 */
 		spin_lock_irqsave(&scst_tm_dbg_lock, flags);
-		tm_dbg_p_cmd_list_waitQ =
-			&tgt_dev->dev->p_cmd_lists->cmd_list_waitQ;
 		tm_dbg_state = INIT_TM_DBG_STATE;
 		tm_dbg_on_state_passes =
 			tm_dbg_on_state_num_passes[tm_dbg_state];
-		__set_bit(SCST_TGT_DEV_UNDER_TM_DBG, &tgt_dev->tgt_dev_flags);
+		tm_dbg_tgt_dev = tgt_dev;
 		PRINT_INFO("LUN 0 connected from initiator %s is under "
-			"TM debugging", tgt_dev->sess->tgt->tgtt->name);
+			"TM debugging (tgt_dev %p)",
+			tgt_dev->sess->initiator_name, tgt_dev);
 		spin_unlock_irqrestore(&scst_tm_dbg_lock, flags);
 	}
+	return;
 }
 
 static void tm_dbg_deinit_tgt_dev(struct scst_tgt_dev *tgt_dev)
 {
-	if (test_bit(SCST_TGT_DEV_UNDER_TM_DBG, &tgt_dev->tgt_dev_flags)) {
+	if (tm_dbg_tgt_dev == tgt_dev) {
 		unsigned long flags;
+		TRACE_MGMT_DBG("Deinit TM debugging tgt_dev %p", tgt_dev);
 		del_timer_sync(&tm_dbg_timer);
 		spin_lock_irqsave(&scst_tm_dbg_lock, flags);
-		tm_dbg_p_cmd_list_waitQ = NULL;
+		tm_dbg_tgt_dev = NULL;
 		spin_unlock_irqrestore(&scst_tm_dbg_lock, flags);
 	}
+	return;
 }
 
 static void tm_dbg_timer_fn(unsigned long arg)
@@ -3634,7 +3640,8 @@ static void tm_dbg_timer_fn(unsigned long arg)
 	tm_dbg_flags.tm_dbg_release = 1;
 	/* Used to make sure that all woken up threads see the new value */
 	smp_wmb();
-	wake_up_all(tm_dbg_p_cmd_list_waitQ);
+	wake_up_all(&tm_dbg_tgt_dev->dev->p_cmd_lists->cmd_list_waitQ);
+	return;
 }
 
 /* Called under scst_tm_dbg_lock and IRQs off */
@@ -3714,8 +3721,7 @@ static void tm_dbg_change_state(void)
 		case TM_DBG_STATE_ABORT:
 			TRACE_MGMT_DBG("%s", "Changing "
 			    "tm_dbg_state to RESET");
-			tm_dbg_state =
-				TM_DBG_STATE_RESET;
+			tm_dbg_state = TM_DBG_STATE_RESET;
 			tm_dbg_flags.tm_dbg_blocked = 0;
 			break;
 		case TM_DBG_STATE_RESET:
@@ -3723,13 +3729,11 @@ static void tm_dbg_change_state(void)
 #ifdef CONFIG_SCST_TM_DBG_GO_OFFLINE
 			    TRACE_MGMT_DBG("%s", "Changing "
 				    "tm_dbg_state to OFFLINE");
-			    tm_dbg_state =
-				TM_DBG_STATE_OFFLINE;
+			    tm_dbg_state = TM_DBG_STATE_OFFLINE;
 #else
 			    TRACE_MGMT_DBG("%s", "Changing "
 				    "tm_dbg_state to ABORT");
-			    tm_dbg_state =
-				TM_DBG_STATE_ABORT;
+			    tm_dbg_state = TM_DBG_STATE_ABORT;
 #endif
 			break;
 		default:
@@ -3740,7 +3744,8 @@ static void tm_dbg_change_state(void)
 	}
 
 	TRACE_MGMT_DBG("%s", "Deleting timer");
-	del_timer(&tm_dbg_timer);
+	del_timer_sync(&tm_dbg_timer);
+	return;
 }
 
 /* No locks */
@@ -3764,8 +3769,7 @@ int tm_dbg_check_cmd(struct scst_cmd *cmd)
 		    (tm_dbg_state == TM_DBG_STATE_ABORT))
 			tm_dbg_change_state();
 		spin_unlock_irqrestore(&scst_tm_dbg_lock, flags);
-	} else if (cmd->tgt_dev && test_bit(SCST_TGT_DEV_UNDER_TM_DBG,
-					&cmd->tgt_dev->tgt_dev_flags)) {
+	} else if (cmd->tgt_dev && (tm_dbg_tgt_dev == cmd->tgt_dev)) {
 		/* Delay 50th command */
 		spin_lock_irqsave(&scst_tm_dbg_lock, flags);
 		if (tm_dbg_flags.tm_dbg_blocked ||
@@ -3816,6 +3820,7 @@ void tm_dbg_release_cmd(struct scst_cmd *cmd)
 		}
 	}
 	spin_unlock_irqrestore(&scst_tm_dbg_lock, flags);
+	return;
 }
 
 /* Might be called under scst_mutex */
@@ -3824,21 +3829,10 @@ void tm_dbg_task_mgmt(struct scst_device *dev, const char *fn, int force)
 	unsigned long flags;
 
 	if (dev != NULL) {
-		struct scst_tgt_dev *tgt_dev;
-		bool found = 0;
+		if (tm_dbg_tgt_dev == NULL)
+			goto out;
 
-		spin_lock_bh(&dev->dev_lock);
-		list_for_each_entry(tgt_dev, &dev->dev_tgt_dev_list,
-					    dev_tgt_dev_list_entry) {
-			if (test_bit(SCST_TGT_DEV_UNDER_TM_DBG,
-					&tgt_dev->tgt_dev_flags)) {
-				found = 1;
-				break;
-			}
-		}
-		spin_unlock_bh(&dev->dev_lock);
-
-		if (!found)
+		if (tm_dbg_tgt_dev->dev != dev)
 			goto out;
 	}
 
@@ -3853,8 +3847,8 @@ void tm_dbg_task_mgmt(struct scst_device *dev, const char *fn, int force)
 		 * value.
 		 */
 		smp_wmb();
-		if (tm_dbg_p_cmd_list_waitQ != NULL)
-			wake_up_all(tm_dbg_p_cmd_list_waitQ);
+		if (tm_dbg_tgt_dev != NULL)
+			wake_up_all(&tm_dbg_tgt_dev->dev->p_cmd_lists->cmd_list_waitQ);
 	} else {
 		TRACE_MGMT_DBG("%s: while OFFLINE state, doing nothing", fn);
 	}
diff --git a/scst/src/scst_targ.c b/scst/src/scst_targ.c
index 224e63581..a9bd93ca4 100644
--- a/scst/src/scst_targ.c
+++ b/scst/src/scst_targ.c
@@ -2087,6 +2087,14 @@ static int scst_exec(struct scst_cmd **active_cmd)
 		int rc;
 
 		cmd->sent_for_exec = 1;
+		/*
+		 * To sync with scst_abort_cmd(). The above assignment must
+		 * be before SCST_CMD_ABORTED test, done later in
+		 * scst_check_local_events(). It's far from here, so the order
+		 * is virtually guaranteed, but let's have it just in case.
+		 */
+		smp_mb();
+
 		cmd->scst_cmd_done = scst_cmd_done_local;
 		cmd->state = SCST_CMD_STATE_LOCAL_EXEC;
 
@@ -3657,6 +3665,9 @@ void scst_done_cmd_mgmt(struct scst_cmd *cmd)
 
 	spin_lock_irqsave(&scst_mcmd_lock, flags);
 
+	if (!test_bit(SCST_CMD_DONE_COUNTED, &cmd->cmd_flags))
+		goto out_unlock;
+
 	list_for_each_entry(mstb, &cmd->mgmt_cmd_list,
 			cmd_mgmt_cmd_list_entry) {
 		struct scst_mgmt_cmd *mcmd = mstb->mcmd;
@@ -3683,6 +3694,7 @@ void scst_done_cmd_mgmt(struct scst_cmd *cmd)
 		}
 	}
 
+out_unlock:
 	spin_unlock_irqrestore(&scst_mcmd_lock, flags);
 
 	if (wake)
@@ -3928,9 +3940,11 @@ void scst_abort_cmd(struct scst_cmd *cmd, struct scst_mgmt_cmd *mcmd,
 
 		mcmd->cmd_finish_wait_count++;
 
-		if (!cmd->done) {
-			TRACE_MGMT_DBG("cmd %p (tag %llu) not done yet",
-				       cmd, (long long unsigned int)cmd->tag);
+		if (cmd->sent_for_exec && !cmd->done) {
+			TRACE_MGMT_DBG("cmd %p (tag %llu) is being executed "
+				"and not done yet", cmd,
+				(long long unsigned int)cmd->tag);
+			set_bit(SCST_CMD_DONE_COUNTED, &cmd->cmd_flags);
 			mcmd->cmd_done_wait_count++;
 		}
 	}
@@ -4086,6 +4100,8 @@ static int scst_abort_task_set(struct scst_mgmt_cmd *mcmd)
 
 	__scst_abort_task_set(mcmd, tgt_dev);
 
+	tm_dbg_task_mgmt(mcmd->mcmd_tgt_dev->dev, "ABORT TASK SET", 0);
+
 	scst_unblock_aborted_cmds(0);
 
 	scst_call_dev_task_mgmt_fn(mcmd, tgt_dev, 0);
@@ -4169,6 +4185,8 @@ static int scst_clear_task_set(struct scst_mgmt_cmd *mcmd)
 					&UA_tgt_devs);
 	}
 
+	tm_dbg_task_mgmt(mcmd->mcmd_tgt_dev->dev, "CLEAR TASK SET", 0);
+
 	scst_unblock_aborted_cmds(1);
 
 	mutex_unlock(&scst_mutex);
@@ -4505,6 +4523,10 @@ static int scst_abort_all_nexus_loss_sess(struct scst_mgmt_cmd *mcmd,
 			rc = scst_call_dev_task_mgmt_fn(mcmd, tgt_dev, 0);
 			if (rc < 0 && mcmd->status == SCST_MGMT_STATUS_SUCCESS)
 				mcmd->status = rc;
+
+			tm_dbg_task_mgmt(tgt_dev->dev, "NEXUS LOSS SESS or "
+				"ABORT ALL SESS or UNREG SESS",
+				(mcmd->fn == SCST_UNREG_SESS_TM));
 		}
 	}
 
@@ -4584,6 +4606,9 @@ static int scst_abort_all_nexus_loss_tgt(struct scst_mgmt_cmd *mcmd,
 					    (mcmd->status == SCST_MGMT_STATUS_SUCCESS))
 						mcmd->status = rc;
 				}
+
+				tm_dbg_task_mgmt(tgt_dev->dev, "NEXUS LOSS or "
+					"ABORT ALL", 0);
 			}
 		}
 	}