	     Open Fabrics Enterprise Distribution (OFED)
		    ipath in OFED 1.1 Release Notes
			  
			   October 2006


Overview
--------
ipath is the low level driver implementation for all QLogic HCAs.


1. MSI (Message Signalled Interrupt) support required with QLogic HCAs
----------------------------------------------------------------------
The QLogic adapter require MSI (Message Signalled Interrupts) to be
enabled in the kernel. In addition, the kernels provided with some Linux
distributions must be rebuilt after installation of a kernel patch to
fix the pci_msi_quirk bug introduced in the 2.6.12 kernel.

1.1. If the InfiniPath driver is being compiled on a machine without
CONFIG_PCI_MSI=y configured, a warning similar to this will appear in
dmesg at boot:

[root@sqa-00 ~]# dmesg | grep ipath
ipath_core 0000:01:00.0: infinipath0: pci_enable_msi failed: -1, interrupts may not work
ipath_core 0000:01:00.0: infinipath0: irq is 0, BIOS error?  Interrupts won't work

OpenFabrics on a QLogic adapter will not work correctly unless the kernel
is configured with CONFIG_PCI_MSI=y.

1.2. Systems with QLogic adapters and which contain the AMD8131 PCI
bridge may require installation of the pci_msi_quirk kernel patch. If
the following messages are displayed on the console during boot, or are
in /var/log/messages, you will need to install the patch.

PCI: MSI quirk detected. pci_msi_quirk set.
path_core 0000:03:00.0: pci_enable_msi failed: -22, interrupts
may not work

NOTE: This problem has been fixed in the 2.6.17 kernel.org kernel.

To install pci_msi_quirk patch and configure MSI for use with QLogic adapter
----------------------------------------------------------------------------
To remedy both of these problems simultaneously, build the
kernel RPMs yourself with stock kernel SRPMs available from your
distribution source, and install the kernel patches provided at
http://www.pathscale.com/infinipath_support/downloads-1.3.html.

See http://www.pathscale.com/docs/infinipath/1.3/msi_patch_notes.txt
for details.

Once these instructions are completed, rebuild the OFED kernel 
modules with the OFED installer.

2. Note: 
--------
When running Fedora Core 4 with the QLogic adapters, it is recommended
to use the 2.6.16 kernel.

3. Known Issues:
----------------
The ipath driver only supports the x86_64 architecture in this release.
