Ben. Multi-MSI is a crap hardware design. Why do you think we have MSI-X? MSI-X as specced is a properly operating irq controller that we don't need kludges to support. Multi-MSI with a full set of kludges almost work but not quite fits the linux irq model. Any hardware designer who choose to implement Multi-MSI instead of MSI-X was not really concerned about having a high performance device. If we can find a way to model the portable capabilities of Multi-MSI cleanly then we can support it, and our drivers and our users and our intermediate layers won't get surprised. So far we have too close fits but neither model really works. Further this is all about driver optimization, so none of this is necessary to have working hardware. Which makes kludges much less appropriate. Modelling Multi-MSI irqs as normal irqs requires a lot of nasty kludges. One of the kludges is allocating a continuous chunk of irq targets, and the resulting fragmentation issues that you get when you start allowing different sized allocations. Overall if Multi-MSI was to become common I think we would really regret it. Eric -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
