ipath in OFED 1.0 Release Notes
===============================
June 2006

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


1. MSI (Message Signalled Interrupt) support required with QLogic HCAs
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The QLogic adapter require MSI (Message Signalled Interrupt) to
be configured on. In addition, some Linux distributions
will require 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 QLogic adapter will not work correctly 
unless the system is configured with CONFIC_PCI_MSI=y.

1.2 Systems installed with QLogic adapter 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 RPMs 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 FC4 with the QLogic adapters, it is recommended to 
use the 2.6.16 kernel.

3. Known Issues:
----------------
The ipath driver cannot be loaded on ia64 RedHat 4.0 U2.
