From: Mika Westerberg <mika.westerberg@linux.intel.com>
Date: Tue, 27 Mar 2018 13:48:35 +0300
Subject: PCI/DPC: Do not enable DPC if AER control is not allowed by the BIOS
Git-commit: 4e5fad429bd179a41fa8b222463397e8cc806cd1
Patch-mainline: v4.17-rc1
References: bsc#1093184
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>
Acked-by: Joerg Roedel <jroedel@suse.de>
---
drivers/pci/pcie/portdrv_acpi.c | 4 ++--
drivers/pci/pcie/portdrv_core.c | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)
--- a/drivers/pci/pcie/portdrv_acpi.c
+++ b/drivers/pci/pcie/portdrv_acpi.c
@@ -50,11 +50,11 @@ void pcie_port_acpi_setup(struct pci_dev
flags = root->osc_control_set;
- *srv_mask = PCIE_PORT_SERVICE_VC | PCIE_PORT_SERVICE_DPC;
+ *srv_mask = PCIE_PORT_SERVICE_VC;
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;
}
--- a/drivers/pci/pcie/portdrv_core.c
+++ b/drivers/pci/pcie/portdrv_core.c
@@ -254,7 +254,7 @@ static int get_port_device_capability(st
}
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;