On Friday 05 of October 2012 16:10:43 Yinghai Lu wrote: > On Fri, Oct 5, 2012 at 4:01 PM, Rafael J. Wysocki <rjw@xxxxxxx> wrote: > > On Thursday 04 of October 2012 15:46:39 Yinghai Lu wrote: > >> > Your patches seem to affect all devices in the ACPI namespace added after > >> > boot, though, not only host bridges. > >> > >> yes, but it still should be safe. > > > > I'm not really sure of that (what about undock/dock, for exmaple?) and it's > > damn ugly. > > only one acpi_driver has .start , that is acpi_pci_root_driver. > > should be clean than with .add/start pair. > > > > >> > And the problem seems to be that the scanning of the ACPI namespace and > >> > configuring the host bridge are kind of independent operations now. What > >> > we should do, actually, seems to be something like this: > >> > > >> > (1) Configure the host bridge when discovered (i.e. do what the current > >> > acpi_pci_root_add() does. > >> > (2) Parse the ACPI namespace under the host bridge (without binding ACPI > >> > drivers to the struct acpi_device objects created in the process, > >> > because they are known to correspond to PCI devices). > >> > (3) Run pci_bus_add_devices() for the bridge. > >> > > >> > in one routine. > >> > >> problem is still there. if 1 still has acpi_pci_root_add and pci_acpi_scan_root > > > > OK, so why don't we do (2) in acpi_pci_root_add(), before pci_acpi_scan_root() > > is called? > > > >> that scan pci devices. what is need is we need to bind 1 and 3 together. > > some one already walk the acpi space, and during that it create > acpi_device for pci_root > and then attach driver for that, aka acpi_pci_root_add is executing. > > Now you want to walking the acpi acpi space to create children devices > before device_add really done for that pci root > acpi device. ? > > is that some kind of nesting? Yes, basically. The idea is to do the scan of the host bridge's children in the ACPI tree synchronously within acpi_pci_root_add() instead of trying to delay the execution of it until the children have been scanned (and using notifiers to kind of trigger the driver binding, i.e. the execution of .add()). > > I don't understand now. You said previously that we need the ACPI namespace > > below the bridge to be scanned before (3), so why do you want to do (3) before > > (2) now? > > purpose is calling pci_bus_add_devices in pci_acpi_scan_root. OK, but what's the reason? Rafael -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- 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
