On Mon, Jul 14, 2025 at 04:50:45PM -0700, Sathyanarayanan Kuppuswamy wrote: > > On 7/14/25 4:00 PM, Sathyanarayanan Kuppuswamy wrote: > > > > On 7/13/25 7:31 AM, Lukas Wunner wrote: > > > Bjorn suggests to "set host->native_pcie_hotplug up front based on > > > CONFIG_HOTPLUG_PCI_PCIE and pcie_ports_native, and pciehp_is_native() > > > would collapse to just an accessor for host->native_pcie_hotplug". > > > > > > Unfortunately only half of this is possible: > > > > > > The check for pcie_ports_native can indeed be moved out of > > > pciehp_is_native() and into acpi_pci_root_create(). > > > > > > The check for CONFIG_HOTPLUG_PCI_PCIE however cannot be eliminated: > > > > > > get_port_device_capability() needs to know whether platform firmware has > > > granted PCIe Native Hot-Plug control to the operating system. If it has > > > and CONFIG_HOTPLUG_PCI_PCIE is disabled, the function disables hotplug > > > interrupts in case BIOS left them enabled. > > > > > > If host->native_pcie_hotplug would be set up front based on > > > CONFIG_HOTPLUG_PCI_PCIE, it would later on be impossible for > > > get_port_device_capability() to tell whether it can safely disable hotplug > > > interrupts: It wouldn't know whether Native Hot-Plug control was granted. > > > > Since pcie_ports_native is a PCI driver specific override option, I am not > > sure it is worth referring to this option in ACPI driver, just to reduce the > > number of pcie_ports_native checks from 2 to 1. > > Never mind. It looks like the goal is to simplify the > pciehp_is_native() call. I would actually like to see more uses of pcie_ports_native removed. It's basically an override of the OS/platform negotiation for control of features, so I think it would make sense to test it somewhere in the negotiate_os_control() rats nest or in acpi_pci_root_create(). > > > Link: https://lore.kernel.org/r/20250627025607.GA1650254@bhelgaas/ > > > Suggested-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> > > > Signed-off-by: Lukas Wunner <lukas@xxxxxxxxx> > > > --- > > > drivers/acpi/pci_root.c | 3 ++- > > > drivers/pci/pci-acpi.c | 3 --- > > > drivers/pci/pcie/portdrv.c | 2 +- > > > 3 files changed, 3 insertions(+), 5 deletions(-) > > > > > > diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c > > > index 74ade4160314..f3de0dc9c533 100644 > > > --- a/drivers/acpi/pci_root.c > > > +++ b/drivers/acpi/pci_root.c > > > @@ -1028,7 +1028,8 @@ struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root, > > > goto out_release_info; > > > host_bridge = to_pci_host_bridge(bus->bridge); > > > - if (!(root->osc_control_set & OSC_PCI_EXPRESS_NATIVE_HP_CONTROL)) > > > + if (!pcie_ports_native && > > > + !(root->osc_control_set & OSC_PCI_EXPRESS_NATIVE_HP_CONTROL)) > > > host_bridge->native_pcie_hotplug = 0; > > > if (!(root->osc_control_set & OSC_PCI_SHPC_NATIVE_HP_CONTROL)) > > > host_bridge->native_shpc_hotplug = 0; > > > diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c > > > index ed7ed66a595b..b513826ea293 100644 > > > --- a/drivers/pci/pci-acpi.c > > > +++ b/drivers/pci/pci-acpi.c > > > @@ -820,9 +820,6 @@ bool pciehp_is_native(struct pci_dev *bridge) > > > if (!IS_ENABLED(CONFIG_HOTPLUG_PCI_PCIE)) > > > return false; > > > - if (pcie_ports_native) > > > - return true; > > > - > > > host = pci_find_host_bridge(bridge->bus); > > > return host->native_pcie_hotplug; > > > } > > > diff --git a/drivers/pci/pcie/portdrv.c b/drivers/pci/pcie/portdrv.c > > > index d1b68c18444f..fa83ebdcfecb 100644 > > > --- a/drivers/pci/pcie/portdrv.c > > > +++ b/drivers/pci/pcie/portdrv.c > > > @@ -223,7 +223,7 @@ static int get_port_device_capability(struct pci_dev *dev) > > > if (dev->is_pciehp && > > > (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT || > > > pci_pcie_type(dev) == PCI_EXP_TYPE_DOWNSTREAM) && > > > - (pcie_ports_native || host->native_pcie_hotplug)) { > > > + host->native_pcie_hotplug) { > > > services |= PCIE_PORT_SERVICE_HP; > > > /* > > > -- > Sathyanarayanan Kuppuswamy > Linux Kernel Developer >
