am7xxx: clarify a comment about copying data in send_data_async()

[libam7xxx.git] / src / am7xxx.c

diff --git a/src/am7xxx.c b/src/am7xxx.c
index b00a6be..3ba56f3 100644 (file)
--- a/src/am7xxx.c
+++ b/src/am7xxx.c
@@ -489,8 +489,8 @@ static int send_data_async(am7xxx_device *dev, uint8_t *buffer, unsigned int len
 
        /* Make a copy of the buffer so the caller can safely reuse it just
         * after libusb_submit_transfer() has returned. This technique
-        * requires more allocations than a proper double-buffering approach
-        * but it takes a lot less code. */
+        * requires more dynamic allocations compared to a proper
+        * double-buffering approach but it takes a lot less code. */
        transfer_buffer = malloc(len);
        if (transfer_buffer == NULL) {
                error(dev->ctx, "cannot allocate transfer buffer (%s)\n",
@@ -784,18 +784,21 @@ static int open_device(am7xxx_context *ctx,
        if (ret < 0) {
                debug(ctx, "libusb_get_configuration after claim failed: %s\n",
                      libusb_error_name(ret));
-               goto out_libusb_close;
+               goto out_libusb_release_interface;
        }
 
        if (current_configuration != (*dev)->desc->configuration) {
                debug(ctx, "libusb configuration changed (expected: %hhu, current: %hhu\n",
                      (*dev)->desc->configuration, current_configuration);
                ret = -EINVAL;
-               goto out_libusb_close;
+               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;