On Fri, 21 Nov 2014, Yijing Wang wrote: > On 2014/11/21 0:31, Marc Zyngier wrote: > > Bjorn, Yijing, > > > > I've just realized that patch c167caf8d174 (PCI/MSI: Remove useless > > bus->msi assignment) completely breaks MSI on arm64 when using the new > > MSI stacked domain: > > Sorry, this is my first part to refactor MSI related code, now how > to get pci msi_controller depends arch > functions(pcibios_msi_controller() or arch_setup_msi_irq()), we are > working on generic pci_host_bridge, after that, we could eventually > eliminate MSI arch functions and find pci dev 's msi controller by > pci_host_bridge->get_msi_controller(). The main question is why you think that pci_host_bridge is the proper place to store that information. On x86 we have DMAR units associated to a single device. Each DMAR unit is a seperate MSI irq domain. Can you guarantee that the pci_host_bridge is the right point to provide the association of the device to the irq domain? So the real question is: What is the association level requirement to properly identify the irqdomain for a specific device on any given architecture with and without IOMMU, interrupt redirection etc. To be honest: I don't know. My gut feeling tells me that it's at the device level, but I really leave that decision to the experts in that field. Thanks, tglx -- 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