On Fri, Sep 19, 2008 at 10:10:20AM -0700, Roland Dreier wrote: > 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). I would query your use of the term 'briefly' -- I think we spent about twenty minutes on this aspect of 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"). What I thought we agreed on last night was: - Add support to the PCI core to let drivers report "I didn't get an MSI, suspect this machine to be broken" (patches already floating around, need one last push to get them merged). - Add support to storage drivers to use that facility, in particular AHCI. - Turn this on by default in Fedora, wait for kerneloops to pick up all the PCI hierarchy traces - Update the blacklists in the kernel - Remove the PCI_MSI config option - Remove the per-driver 'nomsi' options -- Matthew Wilcox Intel Open Source Technology Centre "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step." -- 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
