1) LDC_MODE_RELIABLE is deprecated an unused by anything, plus
   it and LDC_MODE_STREAM were mis-numbered.

2) read_stream() should try to read as much as possible into
   the per-LDC stream buffer area, so do not trim the read_nonraw()
   length by the caller's size parameter.

3) Send data ACKs when necessary in read_nonraw().

4) In read_nonraw() when we get a pure ACK, advance the RX head
   unconditionally past it.

5) Provide the ACKID field in the ldcdgb() packet dump in read_nonraw().
   This helps debugging stream mode LDC channel problems.

6) Decrease verbosity of rx_data_wait() so that it is more useful.
   A debugging message each loop iteration is too much.

7) In process_data_ack() stop the loop checking when we hit lp->tx_tail
   not lp->tx_head.

8) Set the seqid field properly in send_data_nack().
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Virtual devices on Sun Logical Domains are built on top
of a virtual channel framework.  This, with help of hypervisor
interfaces, provides a link layer protocol with basic
handshaking over which virtual device clients and servers
communicate.

Built on top of this is a VIO device protocol which has it's
own handshaking and message types.  At this layer attributes
are exchanged (disk size, network device addresses, etc.)
descriptor rings are registered, and data transfers are
triggers and replied to.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>