On Fri, Sep 28, 2012 at 4:46 PM, Bjorn Helgaas <bhelgaas@xxxxxxxxxx> wrote: > On Thu, Sep 27, 2012 at 2:11 AM, Yinghai Lu <yinghai@xxxxxxxxxx> wrote: >> aka stop acpi root driver in this sequence: acpiphp, iommu, ioapic. >> >> Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx> >> --- >> drivers/acpi/pci_root.c | 2 +- >> 1 files changed, 1 insertions(+), 1 deletions(-) >> >> diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c >> index a27cbb57..012f40d 100644 >> --- a/drivers/acpi/pci_root.c >> +++ b/drivers/acpi/pci_root.c >> @@ -672,7 +672,7 @@ static int acpi_pci_root_remove(struct acpi_device *device, int type) >> pci_stop_root_bus(root->bus); >> >> mutex_lock(&acpi_pci_root_lock); >> - list_for_each_entry(driver, &acpi_pci_drivers, node) >> + list_for_each_entry_reverse(driver, &acpi_pci_drivers, node) >> if (driver->remove) >> driver->remove(root); > > This seems sort of OK just because we call the ->add() methods in > forward order, so it is symmetric to call the ->remove() methods in > reverse order. > > But I'm uncomfortable with using this as a way to enforce ->remove() > ordering across acpiphp, iommu, and ioapic. That seems fragile. > > What are the dependencies between these drivers that require this ordering? ioapic should come at first, and iommu and last is acpiphp. iommu will check if intr-mapping is corresponding to ioapic controller number. also dmar controller will need one normal irq without intr-remapping for error handling. need to use link sequence in Makefile to make sure iommu come at first. -Yinghai -- 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
