Merge tag 'pci-v3.11-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

Pull PCI changes from Bjorn Helgaas:
 "PCI device hotplug
    - Add pci_alloc_dev() interface (Gu Zheng)
    - Add pci_bus_get()/put() for reference counting (Jiang Liu)
    - Fix SR-IOV reference count issues (Jiang Liu)
    - Remove unused acpi_pci_roots list (Jiang Liu)

  MSI
    - Conserve interrupt resources on x86 (Alexander Gordeev)

  AER
    - Force fatal severity when component has been reset (Betty Dall)
    - Reset link below Root Port as well as Downstream Port (Betty Dall)
    - Fix "Firmware first" flag setting (Bjorn Helgaas)
    - Don't parse HEST for non-PCIe devices (Bjorn Helgaas)

  ASPM
    - Warn when we can't disable ASPM as driver requests (Bjorn Helgaas)

  Miscellaneous
    - Add CircuitCo PCI IDs (Darren Hart)
    - Add AMD CZ SATA and SMBus PCI IDs (Shane Huang)
    - Work around Ivytown NTB BAR size issue (Jon Mason)
    - Detect invalid initial BAR values (Kevin Hao)
    - Add pcibios_release_device() (Sebastian Ott)
    - Fix powerpc & sparc PCI_UNKNOWN power state usage (Bjorn Helgaas)"

* tag 'pci-v3.11-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (51 commits)
  MAINTAINERS: Add ACPI folks for ACPI-related things under drivers/pci
  PCI: Add CircuitCo vendor ID and subsystem ID
  PCI: Use pdev->pm_cap instead of pci_find_capability(..,PCI_CAP_ID_PM)
  PCI: Return early on allocation failures to unindent mainline code
  PCI: Simplify IOV implementation and fix reference count races
  PCI: Drop redundant setting of bus->is_added in virtfn_add_bus()
  unicore32/PCI: Remove redundant call of pci_bus_add_devices()
  m68k/PCI: Remove redundant call of pci_bus_add_devices()
  PCI / ACPI / PM: Use correct power state strings in messages
  PCI: Fix comment typo for pcie_pme_remove()
  PCI: Rename pci_release_bus_bridge_dev() to pci_release_host_bridge_dev()
  PCI: Fix refcount issue in pci_create_root_bus() error recovery path
  ia64/PCI: Clean up pci_scan_root_bus() usage
  PCI/AER: Reset link for devices below Root Port or Downstream Port
  ACPI / APEI: Force fatal AER severity when component has been reset
  PCI/AER: Remove "extern" from function declarations
  PCI/AER: Move AER severity defines to aer.h
  PCI/AER: Set dev->__aer_firmware_first only for matching devices
  PCI/AER: Factor out HEST device type matching
  PCI/AER: Don't parse HEST table for non-PCIe devices
  ...

1 files changed, 22 insertions, 7 deletions

diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index d320df6375a2..403a44374ed5 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -714,19 +714,12 @@ void pcie_aspm_powersave_config_link(struct pci_dev *pdev)
 	up_read(&pci_bus_sem);
 }
 
-/*
- * pci_disable_link_state - disable pci device's link state, so the link will
- * never enter specific states
- */
 static void __pci_disable_link_state(struct pci_dev *pdev, int state, bool sem,
 				     bool force)
 {
 	struct pci_dev *parent = pdev->bus->self;
 	struct pcie_link_state *link;
 
-	if (aspm_disabled && !force)
-		return;
-
 	if (!pci_is_pcie(pdev))
 		return;
 
@@ -736,6 +729,19 @@ static void __pci_disable_link_state(struct pci_dev *pdev, int state, bool sem,
 	if (!parent || !parent->link_state)
 		return;
 
+	/*
+	 * A driver requested that ASPM be disabled on this device, but
+	 * if we don't have permission to manage ASPM (e.g., on ACPI
+	 * systems we have to observe the FADT ACPI_FADT_NO_ASPM bit and
+	 * the _OSC method), we can't honor that request.  Windows has
+	 * a similar mechanism using "PciASPMOptOut", which is also
+	 * ignored in this situation.
+	 */
+	if (aspm_disabled && !force) {
+		dev_warn(&pdev->dev, "can't disable ASPM; OS doesn't have ASPM control\n");
+		return;
+	}
+
 	if (sem)
 		down_read(&pci_bus_sem);
 	mutex_lock(&aspm_lock);
@@ -761,6 +767,15 @@ void pci_disable_link_state_locked(struct pci_dev *pdev, int state)
 }
 EXPORT_SYMBOL(pci_disable_link_state_locked);
 
+/**
+ * pci_disable_link_state - Disable device's link state, so the link will
+ * never enter specific states.  Note that if the BIOS didn't grant ASPM
+ * control to the OS, this does nothing because we can't touch the LNKCTL
+ * register.
+ *
+ * @pdev: PCI device
+ * @state: ASPM link state to disable
+ */
 void pci_disable_link_state(struct pci_dev *pdev, int state)
 {
 	__pci_disable_link_state(pdev, state, true, false);