[openib-general] Default of MSI on when MSI support is configured into the kernel

[Woodruff, Robert J]

    Robert> Is there any reason that we cannot just change the mtcha
    Robert> driver to use MSI by default when CONFIG_PCI_MSI is
    Robert> configured in the kernel ?  People that don't support or
    Robert> want to use MSI can always disable it when the build their
    Robert> kernel, or override the values when they do the modprobe.

Roland >It seems that at least the latest Fedora kernels for x86-64
turns on
Roland>CONFIG_PCI_MSI, which means that turning MSI on would break
things on
Roland>Opteron systems using AMD-8131 PCI-X bridges.  I think having the
Roland>default be safe but possibly not maximum peformance is better
than
Roland>being broken on some systems.  It should be possible to extend
the
Roland>interrupt test in the latest driver to set MSI automatically.
Roland>Eventually I may code this up, or someone industrious can do it
sooner.

> - R.

Ok, makes sense. 

woody