+ * Use the FW_CDEV_ISO_ macros to fill in @control.
+ *
+ * For transmit packets, the header length must be a multiple of 4 and specifies
+ * the numbers of bytes in @header that will be prepended to the packet's
+ * payload; these bytes are copied into the kernel and will not be accessed
+ * after the ioctl has returned. The sy and tag fields are copied to the iso
+ * packet header (these fields are specified by IEEE 1394a and IEC 61883-1).
+ * The skip flag specifies that no packet is to be sent in a frame; when using
+ * this, all other fields except the interrupt flag must be zero.
+ *
+ * For receive packets, the header length must be a multiple of the context's
+ * header size; if the header length is larger than the context's header size,
+ * multiple packets are queued for this entry. The sy and tag fields are
+ * ignored. If the sync flag is set, the context drops all packets until
+ * a packet with a matching sy field is received (the sync value to wait for is
+ * specified in the &fw_cdev_start_iso structure). The payload length defines
+ * how many payload bytes can be received for one packet (in addition to payload
+ * quadlets that have been defined as headers and are stripped and returned in
+ * the &fw_cdev_event_iso_interrupt structure). If more bytes are received, the
+ * additional bytes are dropped. If less bytes are received, the remaining
+ * bytes in this part of the payload buffer will not be written to, not even by
+ * the next packet, i.e., packets received in consecutive frames will not
+ * necessarily be consecutive in memory. If an entry has queued multiple
+ * packets, the payload length is divided equally among them.
+ *
+ * When a packet with the interrupt flag set has been completed, the
+ * &fw_cdev_event_iso_interrupt event will be sent. An entry that has queued
+ * multiple receive packets is completed when its last packet is completed.