* taken from: http://unixwiz.net/techtips/gnu-c-attributes.html)
*/
#ifndef __GNUC__
-# define __attribute__(x) /*NOTHING*/
+# define __attribute__(x) /* NOTHING */
#endif
/* Control shared library symbols visibility */
static int open_device(am7xxx_context *ctx,
unsigned int device_index,
- libusb_device* usb_dev,
+ libusb_device *usb_dev,
am7xxx_device **dev)
{
int ret;
*/
current_configuration = -1;
- libusb_get_configuration((*dev)->usb_device, ¤t_configuration);
+ ret = libusb_get_configuration((*dev)->usb_device,
+ ¤t_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
+ * be detached before setting the configuration, but in
+ * practice this is not necessary for most devices.
+ *
+ * For example something like the following function would be
+ * called:
+ * libusb_detach_all_kernel_drivers((*dev)->usb_device);
+ */
ret = libusb_set_configuration((*dev)->usb_device,
(*dev)->desc->configuration);
if (ret < 0) {
* http://libusb.sourceforge.net/api-1.0/caveats.html
*/
current_configuration = -1;
- libusb_get_configuration((*dev)->usb_device, ¤t_configuration);
+ ret = libusb_get_configuration((*dev)->usb_device,
+ ¤t_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;
unsigned int open_device_index, am7xxx_device **dev)
{
ssize_t num_devices;
- libusb_device** list;
+ libusb_device **list;
unsigned int current_index;
int i;
int ret;