* It will contain tag, channel, and sy data instead of a node ID then.
*
* The payload buffer at @data is going to be DMA-mapped except in case of
- * quadlet-sized payload or of local (loopback) requests. Hence make sure that
- * the buffer complies with the restrictions for DMA-mapped memory. The
+ * @length <= 8 or of local (loopback) requests. Hence make sure that the
+ * buffer complies with the restrictions of the streaming DMA mapping API.
* @payload must not be freed before the @callback is called.
*
* In case of request types without payload, @data is NULL and @length is 0.
*
* Returns the RCODE. See fw_send_request() for parameter documentation.
* Unlike fw_send_request(), @data points to the payload of the request or/and
- * to the payload of the response.
+ * to the payload of the response. DMA mapping restrictions apply to outbound
+ * request payloads of >= 8 bytes but not to inbound response payloads.
*/
int fw_run_transaction(struct fw_card *card, int tcode, int destination_id,
int generation, int speed, unsigned long long offset,