| Message ID | 20121207062530.11051.47869.stgit@amt.stowe (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
On Thu, Dec 6, 2012 at 10:25 PM, Myron Stowe <myron.stowe@redhat.com> wrote: > The "ACPI Hot Plug PCI Controller ("acpiphp")" sub-driver may be compiled > as a module. Kernel modules are instantiated somewhat randomly - the > order in which they are linked as the kernel as built - thus if there are > any dependencies on the ordering of attaching sub-drivers, they can not be > effectively dealt with. > > This patch series resolves any potential sequencing inter-dependencies by > converting "acpiphp" sub-driver's functionality to being only supported as > statically built-in to the kernel. Inter-dependencies can then be > effectively handled by explicitly sequencing the addition of such > functionality. some slots may support both acpiphp and pciehp. if make acpiphp to be built-in, user do not have choice anymore. Thanks Yinghai -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, 2012-12-06 at 22:48 -0800, Yinghai Lu wrote: > On Thu, Dec 6, 2012 at 10:25 PM, Myron Stowe <myron.stowe@redhat.com> wrote: > > The "ACPI Hot Plug PCI Controller ("acpiphp")" sub-driver may be compiled > > as a module. Kernel modules are instantiated somewhat randomly - the > > order in which they are linked as the kernel as built - thus if there are > > any dependencies on the ordering of attaching sub-drivers, they can not be > > effectively dealt with. > > > > This patch series resolves any potential sequencing inter-dependencies by > > converting "acpiphp" sub-driver's functionality to being only supported as > > statically built-in to the kernel. Inter-dependencies can then be > > effectively handled by explicitly sequencing the addition of such > > functionality. > > some slots may support both acpiphp and pciehp. > > if make acpiphp to be built-in, user do not have choice anymore. What area are you worried about and how do we exercise that choice today? Here is my current understanding to set a little context - I see the following call chains with respect to pciehp and acpiphp: pcied_init # pciehp module_init pciehp_firmware_init pciehp_acpi_slot_detection_init parse_detect_mode #pcie, acpi, auto (default) pcie_port_service_register acpiphp_init # module_init init_acpi acpiphp_glue_init acpi_pci_register_driver(&acpi_pci_hp_driver) list_for_each_entry(root, &acpi_pci_roots, node) driver->add # for \_SB_.PCI0 add_bridge add_host_bridge bridge = kzalloc(struct acpiphp_bridge) bridge->handle = handle # \_SB_.PCI0 bridge->pci_bus = root_bus #pci_bus 0000:00 init_bridge_misc acpi_walk_namespace(..., register_slot, ...) register_slot if (device_is_managed_by_native_pciehp(pdev)) return AE_OK Does pciehp influence device_is_managed_by_native_pciehp()? If not, it seems that the acpiphp driver will never attach. Looking at ./drivers/pci/hotplug/Makefile, CONFIG_HOTPLUG_PCI_PCIE comes before CONFIG_HOTPLUG_PCI_ACPI so if pciehp and acpiphp are both configured as modules then the load order would seem to be: acpiphp, pciehp: acpiphp ignores, pciehp claims pciehp, acpiphp: pciehp claims, acpiphp ignores To complete the matrix taking built-in vs. module into account - pciehp=y, acpiphp=y pciehp, acpiphp: pciehp claims, acpiphp ignores pciehp=y, acpiphp=m pciehp, acpiphp: pciehp claims, acpiphp ignores pciehp=m, acpiphp=y acpiphp, pciehp: acpiphp ignores, pciehp claims The above combinations all seem to end up with pciehp claiming the slot which raises the question: How do we get acpiphp to claim a slot today? Thanks, Myron > > Thanks > > Yinghai -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/pci/hotplug/Kconfig b/drivers/pci/hotplug/Kconfig index b0e46de..3bf2b82 100644 --- a/drivers/pci/hotplug/Kconfig +++ b/drivers/pci/hotplug/Kconfig @@ -52,15 +52,12 @@ config HOTPLUG_PCI_IBM When in doubt, say N. config HOTPLUG_PCI_ACPI - tristate "ACPI PCI Hotplug driver" + bool "ACPI PCI Hotplug driver" depends on (!ACPI_DOCK && ACPI) || (ACPI_DOCK) help Say Y here if you have a system that supports PCI Hotplug using ACPI. - To compile this driver as a module, choose M here: the - module will be called acpiphp. - When in doubt, say N. config HOTPLUG_PCI_ACPI_IBM
The "ACPI Hot Plug PCI Controller ("acpiphp")" sub-driver may be compiled as a module. Kernel modules are instantiated somewhat randomly - the order in which they are linked as the kernel as built - thus if there are any dependencies on the ordering of attaching sub-drivers, they can not be effectively dealt with. This patch series resolves any potential sequencing inter-dependencies by converting "acpiphp" sub-driver's functionality to being only supported as statically built-in to the kernel. Inter-dependencies can then be effectively handled by explicitly sequencing the addition of such functionality. Signed-off-by: Myron Stowe <myron.stowe@redhat.com> --- drivers/pci/hotplug/Kconfig | 5 +---- 1 files changed, 1 insertions(+), 4 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html