diff options
| author | Karl Palsson <karlp@tweak.net.au> | 2018-07-26 01:11:25 +0300 |
|---|---|---|
| committer | Karl Palsson <karlp@tweak.net.au> | 2018-08-17 03:15:01 +0300 |
| commit | f4bbe7c5bb39086a748810e83220e4e5a336bf50 (patch) | |
| tree | ab8974ad03fc6825f82075e976ca4ae12525dbaf | |
| parent | c55ec70f496d61c8731ccc08e15af500ab61beee (diff) | |
usb: prevent registering duplicate config callbacks
Originally discussed at https://github.com/libopencm3/libopencm3/pull/722
| -rw-r--r-- | include/libopencm3/usb/usbd.h | 3 | ||||
| -rw-r--r-- | lib/usb/usb_standard.c | 3 |
2 files changed, 5 insertions, 1 deletions
diff --git a/include/libopencm3/usb/usbd.h b/include/libopencm3/usb/usbd.h index 04b22c84..96d2c1d5 100644 --- a/include/libopencm3/usb/usbd.h +++ b/include/libopencm3/usb/usbd.h @@ -139,7 +139,8 @@ extern int usbd_register_control_callback(usbd_device *usbd_dev, uint8_t type, /* <usb_standard.c> */ /** Registers a "Set Config" callback - * @return 0 if successful + * @return 0 if successful or already existed. + * @return -1 if no more space was available for callbacks. */ extern int usbd_register_set_config_callback(usbd_device *usbd_dev, usbd_set_config_callback callback); diff --git a/lib/usb/usb_standard.c b/lib/usb/usb_standard.c index fbe89d05..4ce7a8b1 100644 --- a/lib/usb/usb_standard.c +++ b/lib/usb/usb_standard.c @@ -46,6 +46,9 @@ int usbd_register_set_config_callback(usbd_device *usbd_dev, for (i = 0; i < MAX_USER_SET_CONFIG_CALLBACK; i++) { if (usbd_dev->user_callback_set_config[i]) { + if (usbd_dev->user_callback_set_config[i] == callback) { + return 0; + } continue; } |