	     Open Fabrics Enterprise Distribution (OFED)
		    ehca in OFED 1.2 Release Notes

			   June 2007


Overview
--------
ehca is the low level driver implementation for all IBM GX-based HCAs.

ehca Available Parameters
--------------------------
In order to set ehca parameters, add the following line(s) to /etc/modprobe.conf:

	options ib_ehca <parameter>=<value>

whereby <parameter> is one of the following items:
- debug_level     debug level (0: no debug traces (default), 1: with debug traces)
- nr_ports        number of connected ports (default: 2)
- port_act_time   time to wait for port activation (default: 30 sec)
- scaling_code    enable scaling code (default: 1), 0: disable scaling code

New Features
------------
- Scaling code can now be turned on (default) or off at module load time.
  Enabling scaling code helps to distribute processing completions across CPUs.

Fixed Bugs
----------
- Mismatched sync/locking between completion handler and destroy cq
- Reworked irq handler to avoid/reduce missed irq events
- Removed do_mmap() and obsolete prototypes
- Serialized calls to register_mr() (Bugzilla #574)

Known Issues
------------

1. The device driver normally uses both ports. For using just one port connect
the ports as shown in Figure 1 and load the device driver by running
`modprobe ib_ehca nr_ports=1`.

 	  --------- IB Card in p570
	  |
         \ /
	+---+
        | # |
        | # |
        | # |
        | # |  <--- Port 2: NOT CONNECTED
	| # |
        |---|
        | # |
        | # |
        | # |
        | # |  <--- Port 1: CONNECTED TO THE INFINIBAND SWITCH
        | # |
        +---+

*Figure 1:* Connections if only one port is used.

NOTE: In OpenPower 720 and p550 port 1 is at the top, port 2 is at the bottom.

2. Furthermore the port(s) needs to be connected to an active switch port while
loading the ehca device driver.

3. ehca does not compile on RedHat EL4 up5 PPC64 
