1 files changed, 10 insertions, 3 deletions

diff --git a/miscutils/i2c_tools.c b/miscutils/i2c_tools.c
index 03bb03974..7034dc9a8 100644
--- a/miscutils/i2c_tools.c
+++ b/miscutils/i2c_tools.c
@@ -379,8 +379,12 @@ static int i2c_dev_open(int i2cbus)
         sprintf(filename, "/dev/i2c-%d", i2cbus);
         fd = open(filename, O_RDWR);
         if (fd < 0) {
-                filename[8] = '/'; /* change to "/dev/i2c/%d" */
-                fd = xopen(filename, O_RDWR);
+                if (errno == ENOENT) {
+                        filename[8] = '/'; /* change to "/dev/i2c/%d" */
+                        fd = xopen(filename, O_RDWR);
+                } else {
+                        bb_perror_msg_and_die("can't open '%s'", filename);
+                }
         }
 
         return fd;
@@ -1284,13 +1288,16 @@ int i2cdetect_main(int argc UNUSED_PARAM, char **argv)
         unsigned opts;
 
         opt_complementary = "q--r:r--q:" /* mutually exclusive */
-                        "-1:?3"; /* from 1 to 3 args */
+                        "?3"; /* up to 3 args */
         opts = getopt32(argv, optstr);
         argv += optind;
 
         if (opts & opt_l)
                 list_i2c_busses_and_exit();
 
+        if (!argv[0])
+                bb_show_usage();
+
         bus_num = i2c_bus_lookup(argv[0]);
         fd = i2c_dev_open(bus_num);
         get_funcs_matrix(fd, &funcs);