Hi everyone, Yesterday at the Plumbers Conference we talked briefly about removing the PCI_MSI Kconfig option (and just always building MSI support). Coincidentally, I just had a colleague ask me for help because MSI wasn't working on a Fedora 9 system. I investigated a little and discovered that current Fedora kernels are built with CONFIG_PCI_MSI=y but have an extra patch added that defaults MSI to off (and requires booting with "pci=msi" to enable MSI). So it seems one way forward would be to get rid of CONFIG_PCI_MSI and always build MSI support, but add something like CONFIG_PCI_MSI_DEFAULT that allows someone to configure whether to default to allowing MSI (but with the "pci=nomsi" boot option possible), or to default to the Fedora case (no MSI used unless booted with "pci=msi"). Unfortunately, this doesn't reduce the number of Kconfig options we have, but I'm assuming that the Fedora guys can tell us hair-raising stories of boxes that won't boot if a driver enables MSI, and given that they need the "MSI off" default, I think having the same possibility in mainline is a reasonable idea. The alternative is for Fedora to put "pci=nomsi" on their command line by default, but the upgrade issues in adding that to existing setups are probably insurmountable. So does building MSI always but adding PCI_MSI_DEFAULT make sense to everyone? Ben, any PowerPC issues with that? I can supply patches if we agree. - Roland -- 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
