Dear Russell King - ARM Linux, On Thu, 31 Jan 2013 15:08:01 +0000, Russell King - ARM Linux wrote: > On Thu, Jan 31, 2013 at 03:57:37PM +0100, Thomas Petazzoni wrote: > > Indeed. But this function never gets called with bus->number == 0, only > > with bus->number = 1, 2, 3, 4, 5, 6. So those are child busses, and > > therefore they have a parent. > > Having thought about it, yes, that's what I expect, because root bus > resources are never resized. Root bus resources are normally setup > before probing to indicate what size they _can_ be and define what > space is available to the downstream devices. > > Child busses (behind a PCI-2-PCI bridge) are a different matter - these > will be adjusted according to their on-bus devices and the windows for > them sized and allocated appropriately _within_ the confines of the > root bus resource. Ok. > > I am talking about the PCI-to-PCI bridges. I want the I/O windows > > assigned to each PCI-to-PCI bridge to be 64K aligned. The PCI-to-PCI > > bridges are devices that sit on bus 0, each giving access to the child > > buses 1, 2, 3, 4, 5, 6. > > Right, so you've just confirmed that this _is_ the right hook and it > _is_ being called at the right time. Ok. > However, I had interpreted your requirement as the _host_ bridge only > (insufficient information in your previous emails, or I missed it). Might be insufficient information, or wrong terminology on my side. > If that's what your bridge requires, then we need to detect it via > its vendor and device IDs and only apply this fixup to those bridges > which require a 64K alignment. > > So, the IDs are vendor:device = 0x11ab:0x1092 ? And let me get this > straight, it _is_ a specific requirement for this particular bridge > P2P bridge? The vendor/device ID will change. This P2P bridge is emulated. However, I'm not sure why you need to know the vendor:device ID to make the fixup specific. The fixup is already specific to those bridges, since I am just setting pci_sys_data->win_align_io to 64K for the particular buses that are downstream the problematic bridges. So it doesn't affect any other bus on the system, and therefore I don't think this fixup needs to be made specific to a given vendor:device, no? Best regards, Thomas -- Thomas Petazzoni, Free Electrons Kernel, drivers, real-time and embedded Linux development, consulting, training and support. http://free-electrons.com -- 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
