On Tue, Mar 27, 2018 at 01:48:35PM +0300, Mika Westerberg wrote:
> Commit eed85ff4c0da ("PCI/DPC: Enable DPC only if AER is available")
> made DPC control dependent whether AER is enabled in the OS. However, it
> does not take into account situations where BIOS has not given OS
> control of AER:
>
> acpi PNP0A08:00: _OSC: OS supports [ExtendedConfig ASPM ClockPM Segments MSI]
> acpi PNP0A08:00: _OSC: platform does not support [AER]
> acpi PNP0A08:00: _OSC: OS now controls [PCIeHotplug PME PCIeCapability]
>
> I think here it is better not to enable DPC even if the capability is
> available because then it would be against what "Determination of DPC
> Control" note in PCIe 4.0 sec 6.1.10 recommends.
>
> Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
Applied to pci/portdrv for v4.17, thanks!
> ---
> Changes from v1:
>
> * Rebased on top of pci.git/pci/portdrv
> * Dropped the other patch that disables interrupt generation during
> suspend because there is development on-going to get rid of separate
> PCIe portdrv and move everything to the PCI core instead.
>
> drivers/pci/pcie/portdrv_acpi.c | 4 ++--
> drivers/pci/pcie/portdrv_core.c | 2 +-
> 2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/pci/pcie/portdrv_acpi.c b/drivers/pci/pcie/portdrv_acpi.c
> index 9d12650dc2ae..8ab5d434b9c6 100644
> --- a/drivers/pci/pcie/portdrv_acpi.c
> +++ b/drivers/pci/pcie/portdrv_acpi.c
> @@ -47,11 +47,11 @@ void pcie_port_acpi_setup(struct pci_dev *port, int *srv_mask)
>
> flags = root->osc_control_set;
>
> - *srv_mask = PCIE_PORT_SERVICE_DPC;
> + *srv_mask = 0;
> if (flags & OSC_PCI_EXPRESS_NATIVE_HP_CONTROL)
> *srv_mask |= PCIE_PORT_SERVICE_HP;
> if (flags & OSC_PCI_EXPRESS_PME_CONTROL)
> *srv_mask |= PCIE_PORT_SERVICE_PME;
> if (flags & OSC_PCI_EXPRESS_AER_CONTROL)
> - *srv_mask |= PCIE_PORT_SERVICE_AER;
> + *srv_mask |= PCIE_PORT_SERVICE_AER | PCIE_PORT_SERVICE_DPC;
> }
> diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
> index a1f838f2646a..eb463966094e 100644
> --- a/drivers/pci/pcie/portdrv_core.c
> +++ b/drivers/pci/pcie/portdrv_core.c
> @@ -236,7 +236,7 @@ static int get_port_device_capability(struct pci_dev *dev)
> }
>
> if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC) &&
> - pci_aer_available())
> + pci_aer_available() && services & PCIE_PORT_SERVICE_AER)
> services |= PCIE_PORT_SERVICE_DPC;
>
> return services;
> --
> 2.16.2
>
> --
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