transport selection tweaks

[openocd.git] / src / jtag / transport.c

diff --git a/src/jtag/transport.c b/src/jtag/transport.c
index cce45fb7a246fd144e03c563a84aefc9e579198f..d290bd2cff0168fc2059b7b14446c4c1c21b6341 100644 (file)
--- a/src/jtag/transport.c
+++ b/src/jtag/transport.c
@@ -101,6 +101,10 @@ int allow_transports(struct command_context *ctx, const char **vector)
         *
         * REVISIT should we validate that?  and insist there's
         * at least one non-NULL element in that list?
+        *
+        * ... allow removals, e.g. external strapping prevents use
+        * of one transport; C code should be definitive about what
+        * can be used when all goes well.
         */
        if (allowed_transports != NULL || session) {
                LOG_ERROR("Can't modify the set of allowed transports.");
@@ -116,6 +120,8 @@ int allow_transports(struct command_context *ctx, const char **vector)
                                vector[0]);
                return transport_select(ctx, vector [0]);
        } else {
+               /* guard against user config errors */
+               LOG_WARNING("must select a transport.");
                while (*vector)
                        LOG_DEBUG("allow transport '%s'", *vector++);
                return ERROR_OK;
@@ -304,13 +310,14 @@ COMMAND_HANDLER(handle_transport_select)
        /* Is this transport supported by our debug adapter?
         * Example, "JTAG-only" means SWD is not supported.
         *
-        * NOTE:  requires adapter to have been set up, including
-        * declaring transport via C code or Tcl script.
+        * NOTE:  requires adapter to have been set up, with
+        * transports declared via C.
         */
        if (!allowed_transports) {
                LOG_ERROR("Debug adapter doesn't support any transports?");
                return ERROR_FAIL;
        }
+
        for (unsigned i = 0; allowed_transports[i]; i++) {
 
                if (strcmp(allowed_transports[i], CMD_ARGV[0]) == 0)