am7xxx: release the interface when needed in open_device()

[libam7xxx.git] / src / am7xxx.c

diff --git a/src/am7xxx.c b/src/am7xxx.c
index 6595ccf..2ba9561 100644 (file)
--- a/src/am7xxx.c
+++ b/src/am7xxx.c
@@ -734,7 +734,14 @@ static int open_device(am7xxx_context *ctx,
         */
 
        current_configuration = -1;
-       libusb_get_configuration((*dev)->usb_device, &current_configuration);
+       ret = libusb_get_configuration((*dev)->usb_device,
+                                      &current_configuration);
+       if (ret < 0) {
+               debug(ctx, "libusb_get_configuration failed: %s\n",
+                     libusb_error_name(ret));
+               goto out_libusb_close;
+       }
+
        if (current_configuration != (*dev)->desc->configuration) {
                /*
                 * In principle kernel drivers bound to each interface should
@@ -772,16 +779,26 @@ static int open_device(am7xxx_context *ctx,
         * http://libusb.sourceforge.net/api-1.0/caveats.html
         */
        current_configuration = -1;
-       libusb_get_configuration((*dev)->usb_device, &current_configuration);
+       ret = libusb_get_configuration((*dev)->usb_device,
+                                      &current_configuration);
+       if (ret < 0) {
+               debug(ctx, "libusb_get_configuration after claim failed: %s\n",
+                     libusb_error_name(ret));
+               goto out_libusb_release_interface;
+       }
+
        if (current_configuration != (*dev)->desc->configuration) {
-               debug(ctx, "libusb configuration changed\n");
-               debug(ctx, "Cannot claim interface %hhu\n",
-                     (*dev)->desc->interface_number);
-               goto out_libusb_close;
+               debug(ctx, "libusb configuration changed (expected: %hhu, current: %hhu\n",
+                     (*dev)->desc->configuration, current_configuration);
+               ret = -EINVAL;
+               goto out_libusb_release_interface;
        }
 out:
        return ret;
 
+out_libusb_release_interface:
+       libusb_release_interface((*dev)->usb_device,
+                                (*dev)->desc->interface_number);
 out_libusb_close:
        libusb_close((*dev)->usb_device);
        (*dev)->usb_device = NULL;