Re: [PATCH v1 4/9] PCI/portdrv: Disable port driver in compat mode

From: Rafael J. Wysocki
Date: Wed Mar 07 2018 - 05:28:40 EST


On Wednesday, March 7, 2018 7:13:45 AM CET Bjorn Helgaas wrote:
> From: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
>
> The "pcie_ports=compat" kernel parameter sets pcie_ports_disabled, which is
> intended to disable the PCIe port driver. But even when it was disabled,
> we registered pcie_portdriver so we could work around a BIOS PME issue (see
> fe31e69740ed ("PCI/PCIe: Clear Root PME Status bits early during system
> resume")).
>
> Registering the driver meant that the pcie_portdrv_probe() path called
> pci_enable_device(), pci_save_state(), pm_runtime_set_autosuspend_delay(),
> pm_runtime_use_autosuspend(), etc., even when the driver was disabled.
>
> We've since moved the BIOS PME workaround from the port driver to the core,
> so stop registering the PCIe port driver in compat mode.
>
> This means "pcie_ports=compat" will now be basically the same as turning
> off CONFIG_PCIEPORTBUS completely.
>
> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> ---
> drivers/pci/pcie/portdrv_core.c | 3 ---
> drivers/pci/pcie/portdrv_pci.c | 2 +-
> 2 files changed, 1 insertion(+), 4 deletions(-)
>
> diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
> index ef3bad4ad010..9db77c683732 100644
> --- a/drivers/pci/pcie/portdrv_core.c
> +++ b/drivers/pci/pcie/portdrv_core.c
> @@ -212,9 +212,6 @@ static int get_port_device_capability(struct pci_dev *dev)
> int services = 0;
> int cap_mask = 0;
>
> - if (pcie_ports_disabled)
> - return 0;
> -
> cap_mask = PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP
> | PCIE_PORT_SERVICE_VC;
> if (pci_aer_available())
> diff --git a/drivers/pci/pcie/portdrv_pci.c b/drivers/pci/pcie/portdrv_pci.c
> index f91afd09e356..c08ebd237242 100644
> --- a/drivers/pci/pcie/portdrv_pci.c
> +++ b/drivers/pci/pcie/portdrv_pci.c
> @@ -262,7 +262,7 @@ static int __init pcie_portdrv_init(void)
> int retval;
>
> if (pcie_ports_disabled)
> - return pci_register_driver(&pcie_portdriver);
> + return -EACCES;
>
> dmi_check_system(pcie_portdrv_dmi_table);
>
>
>

Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>