X-Git-Url: https://review.openocd.org/gitweb?a=blobdiff_plain;f=src%2Fjtag%2Fdrivers%2Fdriver.c;h=e52816d3ab7a2ea44e4105f7b068d8c7b85c9905;hb=HEAD;hp=fae2aad2296e8dbd33be27c446a0561c9e31b611;hpb=8d3728f931888d2e9a9bc5a31d26c8327649e676;p=openocd.git

diff --git a/src/jtag/drivers/driver.c b/src/jtag/drivers/driver.c
index fae2aad229..e52816d3ab 100644
--- a/src/jtag/drivers/driver.c
+++ b/src/jtag/drivers/driver.c
@@ -116,12 +116,21 @@ int interface_jtag_add_dr_scan(struct jtag_tap *active, int in_num_fields,
 	/* count devices in bypass */
 
 	size_t bypass_devices = 0;
+	size_t all_devices = 0;
 
 	for (struct jtag_tap *tap = jtag_tap_next_enabled(NULL); tap; tap = jtag_tap_next_enabled(tap)) {
+		all_devices++;
+
 		if (tap->bypass)
 			bypass_devices++;
 	}
 
+	if (all_devices == bypass_devices) {
+		LOG_ERROR("At least one TAP shouldn't be in BYPASS mode");
+
+		return ERROR_FAIL;
+	}
+
 	struct jtag_command *cmd = cmd_queue_alloc(sizeof(struct jtag_command));
 	struct scan_command *scan = cmd_queue_alloc(sizeof(struct scan_command));
 	struct scan_field *out_fields = cmd_queue_alloc((in_num_fields + bypass_devices) * sizeof(struct scan_field));