diff --git a/include/net/nfc/digital.h b/include/net/nfc/digital.h index 36acecd5f06c..81af21e9bcd4 100644 --- a/include/net/nfc/digital.h +++ b/include/net/nfc/digital.h @@ -122,6 +122,16 @@ typedef void (*nfc_digital_cmd_complete_t)(struct nfc_digital_dev *ddev, * switch_rf to turn the radio on. A call to in|tg_configure_hw must turn * the device radio on. * @abort_cmd: Discard the last sent command. + * + * Notes: Asynchronous functions have a timeout parameter. It is the driver + * responsibility to call the digital stack back through the + * nfc_digital_cmd_complete_t callback when no RF respsonse has been + * received within the specified time (in milliseconds). In that case the + * driver must set the resp sk_buff to ERR_PTR(-ETIMEDOUT). + * Since the digital stack serializes commands to be sent, it's mandatory + * for the driver to handle the timeout correctly. Otherwise the stack + * would not be able to send new commands, waiting for the reply of the + * current one. */ struct nfc_digital_ops { int (*in_configure_hw)(struct nfc_digital_dev *ddev, int type,