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 9d12650dc2ae8fc80fa8228d8a3a0d15fc6be454..8ab5d434b9c608bf4690509a9b6b0df2b344b928 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 099ef7ac615b36df5f5a800b065550f7355607aa..4ba4d05a5e4c2311f30a42f0fc641a5f81a84337 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;