X-Git-Url: https://git.ao2.it/libam7xxx.git/blobdiff_plain/224afa9a6451c66e07cf5bf8912245c1f4563e2e..bc54402f45a199d3aba10c42b1ee9cf2b0197fa2:/src/am7xxx.c diff --git a/src/am7xxx.c b/src/am7xxx.c index 8837e41..3ba56f3 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", @@ -704,10 +704,11 @@ 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; + int current_configuration; *dev = find_device(ctx, device_index); if (*dev == NULL) { @@ -724,7 +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; } @@ -732,26 +733,72 @@ static int open_device(am7xxx_context *ctx, * to close it again before bailing out. */ - ret = libusb_set_configuration((*dev)->usb_device, - (*dev)->desc->configuration); + current_configuration = -1; + ret = libusb_get_configuration((*dev)->usb_device, + ¤t_configuration); if (ret < 0) { - debug(ctx, "libusb_set_configuration failed\n"); - debug(ctx, "Cannot set configuration %hhu\n", - (*dev)->desc->configuration); + 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) { + 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; } + + /* Checking that the configuration has not changed, as suggested in + * http://libusb.sourceforge.net/api-1.0/caveats.html + */ + current_configuration = -1; + 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 (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; @@ -767,13 +814,13 @@ typedef enum { * This is where the central logic of multi-device support is. * * When 'op' == SCAN_OP_BUILD_DEVLIST the parameters 'open_device_index' and - * 'dev' are ignored; the function returns 0 on success and a negative value + * 'dev' are ignored; the function returns 0 on success or a negative value * on error. * * When 'op' == SCAN_OP_OPEN_DEVICE the function opens the supported USB * device with index 'open_device_index' and returns the correspondent * am7xxx_device in the 'dev' parameter; the function returns the value from - * open_device(), which is 0 on success, 1 if the device was already open and + * open_device(), which is 0 on success, 1 if the device was already open or * a negative value on error. * * NOTES: @@ -785,7 +832,7 @@ 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;