PCI/DPC: Do not enable DPC if AER control is not allowed by the BIOS

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@linux.intel.com>
Signed-off-by: Bjorn Helgaas <helgaas@kernel.org>

diff --git a/drivers/pci/pcie/portdrv_acpi.c b/drivers/pci/pcie/portdrv_acpi.c
index 9d12650..8ab5d43 100644 (file)
--- 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 099ef7a..4ba4d05 100644 (file)
--- a/drivers/pci/pcie/portdrv_core.c
+++ b/drivers/pci/pcie/portdrv_core.c
@@ -242,7 +242,7 @@ 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;