On Tue, May 29, 2018 at 07:01:55PM +0300, Mika Westerberg wrote:
> When a system is using native PCIe hotplug for Thunderbolt it will be
> only present in the system when there is a device connected. This pretty
> much follows the BIOS assisted hotplug behaviour.
> ...
> +static void acpiphp_native_scan_bridge(struct pci_dev *bridge)
> +{
> + struct pci_bus *bus = bridge->subordinate;
> + struct pci_dev *dev;
> + int max;
> +
> + if (!bus)
> + return;
> +
> + max = bus->busn_res.start;
> + /* Scan already configured non-hotplug bridges */
> + for_each_pci_bridge(dev, bus) {
> + if (!dev->is_hotplug_bridge)
Here we test "dev->is_hotplug_bridge" and below we use
"hotplug_is_native(bus->self)". Is the difference significant, or
should we use hotplug_is_native() here as well?
If we do need to use is_hotplug_bridge here, maybe a comment about the
difference would be helpful.
> + max = pci_scan_bridge(bus, dev, max, 0);
> + }
> +
> + /* Scan non-hotplug bridges that need to be reconfigured */
> + for_each_pci_bridge(dev, bus) {
> + if (!dev->is_hotplug_bridge)
> + max = pci_scan_bridge(bus, dev, max, 1);
> + }
> +}
> +
> /**
> * enable_slot - enable, configure a slot
> * @slot: slot to be enabled
> @@ -442,25 +466,42 @@ static void enable_slot(struct acpiphp_slot *slot)
> struct pci_dev *dev;
> struct pci_bus *bus = slot->bus;
> struct acpiphp_func *func;
> - int max, pass;
> - LIST_HEAD(add_list);
>
> - acpiphp_rescan_slot(slot);
> - max = acpiphp_max_busnr(bus);
> - for (pass = 0; pass < 2; pass++) {
> + if (bus->self && hotplug_is_native(bus->self)) {
> + /*
> + * If native hotplug is used, it will take care of hotplug
> + * slot management and resource allocation for hotplug
> + * bridges. However, ACPI hotplug may still be used for
> + * non-hotplug bridges to bring in additional devices such
> + * as Thunderbolt host controller.
> + */
> for_each_pci_bridge(dev, bus) {
> - if (PCI_SLOT(dev->devfn) != slot->device)
> - continue;
> -
> - max = pci_scan_bridge(bus, dev, max, pass);
> - if (pass && dev->subordinate) {
> - check_hotplug_bridge(slot, dev);
> - pcibios_resource_survey_bus(dev->subordinate);
> - __pci_bus_size_bridges(dev->subordinate, &add_list);
> + if (PCI_SLOT(dev->devfn) == slot->device)
> + acpiphp_native_scan_bridge(dev);
> + }
> + pci_assign_unassigned_bridge_resources(bus->self);
> + } else {
