X-Git-Url: https://git.ao2.it/libam7xxx.git/blobdiff_plain/313d4a702aefeac3c8360141ae9037a8fdd47746..9e24b798ba1376655756c55fd157661148799422:/src/am7xxx.c
diff --git a/src/am7xxx.c b/src/am7xxx.c
index 321a193..94b01ac 100644
--- a/src/am7xxx.c
+++ b/src/am7xxx.c
@@ -34,7 +34,7 @@
* 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 */
@@ -385,8 +385,8 @@ static int read_data(am7xxx_device *dev, uint8_t *buffer, unsigned int len)
ret = libusb_bulk_transfer(dev->usb_device, 0x81, buffer, len, &transferred, 0);
if (ret != 0 || (unsigned int)transferred != len) {
- error(dev->ctx, "ret: %d\ttransferred: %d (expected %u)\n",
- ret, transferred, len);
+ error(dev->ctx, "%s. Transferred: %d (expected %u)\n",
+ libusb_error_name(ret), transferred, len);
return ret;
}
@@ -404,8 +404,8 @@ static int send_data(am7xxx_device *dev, uint8_t *buffer, unsigned int len)
ret = libusb_bulk_transfer(dev->usb_device, 0x1, buffer, len, &transferred, 0);
if (ret != 0 || (unsigned int)transferred != len) {
- error(dev->ctx, "ret: %d\ttransferred: %d (expected %u)\n",
- ret, transferred, len);
+ error(dev->ctx, "%s. Transferred: %d (expected %u)\n",
+ libusb_error_name(ret), transferred, len);
return ret;
}
@@ -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",
@@ -704,7 +704,7 @@ static am7xxx_device *find_device(am7xxx_context *ctx,
static int open_device(am7xxx_context *ctx,
unsigned int device_index,
- libusb_device* usb_dev,
+ libusb_device *usb_dev,
am7xxx_device **dev)
{
int ret;
@@ -725,7 +725,7 @@ static int open_device(am7xxx_context *ctx,
ret = libusb_open(usb_dev, &((*dev)->usb_device));
if (ret < 0) {
- debug(ctx, "libusb_open failed\n");
+ debug(ctx, "libusb_open failed: %s\n", libusb_error_name(ret));
goto out;
}
@@ -734,22 +734,53 @@ static int open_device(am7xxx_context *ctx,
*/
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, before setting a new configuration, kernel
+ * drivers should be detached from _all_ interfaces; for
+ * example calling something like the following "invented"
+ * function _before_ setting the new configuration:
+ *
+ * libusb_detach_all_kernel_drivers((*dev)->usb_device);
+ *
+ * However, in practice, this is not necessary for most
+ * devices as they have only one configuration.
+ *
+ * When a device only has one configuration:
+ *
+ * - if there was a kernel driver bound to the device, it
+ * had already set the configuration and the call below
+ * will be skipped;
+ *
+ * - if no kernel driver was bound to the device, the call
+ * below will suceed.
+ */
ret = libusb_set_configuration((*dev)->usb_device,
(*dev)->desc->configuration);
if (ret < 0) {
- debug(ctx, "libusb_set_configuration failed\n");
+ debug(ctx, "libusb_set_configuration failed: %s\n",
+ libusb_error_name(ret));
debug(ctx, "Cannot set configuration %hhu\n",
(*dev)->desc->configuration);
goto out_libusb_close;
}
}
+ libusb_set_auto_detach_kernel_driver((*dev)->usb_device, 1);
+
ret = libusb_claim_interface((*dev)->usb_device,
(*dev)->desc->interface_number);
if (ret < 0) {
- debug(ctx, "libusb_claim_interface failed\n");
+ debug(ctx, "libusb_claim_interface failed: %s\n",
+ libusb_error_name(ret));
debug(ctx, "Cannot claim interface %hhu\n",
(*dev)->desc->interface_number);
goto out_libusb_close;
@@ -759,16 +790,26 @@ 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, ¤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;
@@ -802,7 +843,7 @@ static int scan_devices(am7xxx_context *ctx, scan_op op,
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;
@@ -1060,8 +1101,10 @@ AM7XXX_PUBLIC int am7xxx_init(am7xxx_context **ctx)
(*ctx)->log_level = AM7XXX_LOG_TRACE;
ret = libusb_init(&((*ctx)->usb_context));
- if (ret < 0)
+ if (ret < 0) {
+ error(*ctx, "libusb_init failed: %s\n", libusb_error_name(ret));
goto out_free_context;
+ }
libusb_set_debug((*ctx)->usb_context, LIBUSB_LOG_LEVEL_INFO);