Merge tag 'pci-v5.11-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

Pull PCI updates from Bjorn Helgaas:
 "Enumeration:
   - Decode PCIe 64 GT/s link speed (Gustavo Pimentel)
   - Remove unused HAVE_PCI_SET_MWI (Heiner Kallweit)
   - Reduce pci_set_cacheline_size() message to debug level (Heiner
     Kallweit)
   - Fix pci_slot_release() NULL pointer dereference (Jubin Zhong)
   - Unify ECAM constants in native PCI Express drivers (Krzysztof
     Wilczyński)
   - Return u8 from pci_find_capability() and similar (Puranjay Mohan)
   - Return u16 from pci_find_ext_capability() and similar (Bjorn
     Helgaas)
   - Fix ACPI companion lookup for device 0 on the root bus (Rafael J.
     Wysocki)

  Resource management:
   - Keep both device and resource name for config space remaps
     (Alexander Lobakin)
   - Bounds-check command-line resource alignment requests (Bjorn
     Helgaas)
   - Fix overflow in command-line resource alignment requests (Colin Ian
     King)

  Driver binding:
   - Avoid duplicate IDs in driver dynamic IDs list (Zhenzhong Duan)

  Power management:
   - Save/restore Precision Time Measurement Capability for
     suspend/resume (David E. Box)
   - Disable PTM during suspend to save power (David E. Box)
   - Add sysfs attribute for device power state (Maximilian Luz)
   - Rename pci_wakeup_bus() to pci_resume_bus() (Mika Westerberg)
   - Do not generate wakeup event when runtime resuming device (Mika
     Westerberg)
   - Save/restore ASPM L1SS Capability for suspend/resume (Vidya Sagar)

  Virtualization:
   - Mark AMD Raven iGPU ATS as broken in some platforms (Alex Deucher)
   - Add function 1 DMA alias quirk for Marvell 9215 SATA controller
     (Bjorn Helgaas)

  MSI:
   - Disable MSI for Pericom PCIe-USB adapter (Andy Shevchenko)
   - Improve warnings for 32-bit-limited MSI support (Vidya Sagar)

  Error handling:
   - Cache RCEC EA Capability offset in pci_init_capabilities() (Sean V
     Kelley)
   - Rename reset_link() to reset_subordinates() (Sean V Kelley)
   - Write AER Capability only when we control it (Sean V Kelley)
   - Clear AER status only when we control AER (Sean V Kelley)
   - Bind RCEC devices to the Root Port driver (Qiuxu Zhuo)
   - Recover from RCiEP AER errors (Qiuxu Zhuo)
   - Recover from RCEC AER errors (Sean V Kelley)
   - Add pcie_link_rcec() to associate RCiEPs (Sean V Kelley)
   - Add pcie_walk_rcec() to RCEC AER handling (Sean V Kelley)
   - Add pcie_walk_rcec() to RCEC PME handling (Sean V Kelley)
   - Add RCEC AER error injection support (Qiuxu Zhuo)

  Broadcom iProc PCIe controller driver:
   - Fix out-of-bound array accesses (Bharat Gooty)
   - Invalidate correct PAXB inbound windows (Roman Bacik)
   - Enhance PCIe Link information display (Srinath Mannam)

  Cadence PCIe controller driver:
   - Make "cdns,max-outbound-regions" property optional (Kishon Vijay
     Abraham I)

  Intel VMD host bridge driver:
   - Offset client MSI-X vectors (Jon Derrick)
   - Update type of __iomem pointers (Krzysztof Wilczyński)

  NVIDIA Tegra PCIe controller driver:
   - Move "dbi" accesses to post common DWC initialization (Vidya Sagar)
   - Read "dbi" base address to program in application logic (Vidya
     Sagar)
   - Fix ASPM-L1SS advertisement disable code (Vidya Sagar)
   - Set DesignWare IP version (Vidya Sagar)
   - Continue unconfig sequence even if parts fail (Vidya Sagar)
   - Check return value of tegra_pcie_init_controller() (Vidya Sagar)
   - Disable LTSSM during L2 entry (Vidya Sagar)

  Qualcomm PCIe controller driver:
   - Document PCIe bindings for SM8250 SoC (Manivannan Sadhasivam)
   - Add SM8250 SoC support (Manivannan Sadhasivam)
   - Add support for configuring BDF to SID mapping for SM8250
     (Manivannan Sadhasivam)

  Renesas R-Car PCIe controller driver:
   - rcar: Drop unused members from struct rcar_pcie_host (Lad
     Prabhakar)
   - PCI: rcar-pci-host: Document r8a774e1 bindings (Lad Prabhakar)
   - PCI: rcar-pci-host: Convert bindings to json-schema (Yoshihiro
     Shimoda)
   - PCI: rcar-pci-host: Document r8a77965 bindings (Yoshihiro Shimoda)

  Samsung Exynos PCIe controller driver:
   - Rework driver to support Exynos5433 PCIe PHY (Jaehoon Chung)
   - Rework driver to support Exynos5433 variant (Jaehoon Chung)
   - Drop samsung,exynos5440-pcie binding (Marek Szyprowski)
   - Add the samsung,exynos-pcie binding (Marek Szyprowski)
   - Add the samsung,exynos-pcie-phy binding (Marek Szyprowski)

  Synopsys DesignWare PCIe controller driver:
   - Support multiple ATU memory regions (Rob Herring)
   - Move intel-gw ATU offset out of driver match data (Rob Herring)
   - Move "dbi", "dbi2", and "addr_space" resource setup into common
     code (Rob Herring)
   - Remove intel-gw unneeded function wrappers (Rob Herring)
   - Ensure all outbound ATU windows are reset (Rob Herring)
   - Use the common MSI irq_chip in dra7xx (Rob Herring)
   - Drop the .set_num_vectors() host op (Rob Herring)
   - Move MSI interrupt setup into DWC common code (Rob Herring)
   - Rework MSI initialization (Rob Herring)
   - Move link handling into common code (Rob Herring)
   - Move dw_pcie_msi_init() into core (Rob Herring)
   - Move dw_pcie_setup_rc() to DWC common code (Rob Herring)
   - Remove unnecessary wrappers around dw_pcie_host_init() (Rob
     Herring)
   - Drop keystone duplicated 'num-viewport'" (Rob Herring)
   - Move inbound and outbound windows to common struct (Rob Herring)
   - Detect number of iATU windows (Rob Herring)
   - Warn if non-prefetchable memory aperture size is > 32-bit (Vidya
     Sagar)
   - Add support to program ATU for >4GB memory (Vidya Sagar)
   - Set 32-bit DMA mask for MSI target address allocation (Vidya Sagar)

  TI J721E PCIe driver:
   - Fix "ti,syscon-pcie-ctrl" to take argument (Kishon Vijay Abraham I)
   - Add host mode dt-bindings for TI's J7200 SoC (Kishon Vijay Abraham
     I)
   - Add EP mode dt-bindings for TI's J7200 SoC (Kishon Vijay Abraham I)
   - Get offset within "syscon" from "ti,syscon-pcie-ctrl" phandle arg
     (Kishon Vijay Abraham I)

  TI Keystone PCIe controller driver:
   - Enable compile-testing on !ARM (Alex Dewar)"

* tag 'pci-v5.11-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (100 commits)
  PCI: Add function 1 DMA alias quirk for Marvell 9215 SATA controller
  PCI/ACPI: Fix companion lookup for device 0 on the root bus
  PCI: Keep both device and resource name for config space remaps
  PCI: xgene: Removed unused ".bus_shift" initialisers from pci-xgene.c
  PCI: vmd: Update type of the __iomem pointers
  PCI: iproc: Convert to use the new ECAM constants
  PCI: thunder-pem: Add constant for custom ".bus_shift" initialiser
  PCI: Unify ECAM constants in native PCI Express drivers
  PCI: Disable PTM during suspend to save power
  PCI/PTM: Save/restore Precision Time Measurement Capability for suspend/resume
  PCI: Mark AMD Raven iGPU ATS as broken in some platforms
  PCI: j721e: Get offset within "syscon" from "ti,syscon-pcie-ctrl" phandle arg
  dt-bindings: PCI: Add EP mode dt-bindings for TI's J7200 SoC
  dt-bindings: PCI: Add host mode dt-bindings for TI's J7200 SoC
  dt-bindings: pci: ti,j721e: Fix "ti,syscon-pcie-ctrl" to take argument
  PCI: dwc: Set 32-bit DMA mask for MSI target address allocation
  PCI: qcom: Add support for configuring BDF to SID mapping for SM8250
  PCI: Reduce pci_set_cacheline_size() message to debug level
  PCI: Remove unused HAVE_PCI_SET_MWI
  PCI: qcom: Add SM8250 SoC support
  ...

1 files changed, 21 insertions, 1 deletions

diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index 745a4e0c4994..53502a751914 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -1162,14 +1162,34 @@ void acpi_pci_remove_bus(struct pci_bus *bus)
 static struct acpi_device *acpi_pci_find_companion(struct device *dev)
 {
 	struct pci_dev *pci_dev = to_pci_dev(dev);
+	struct acpi_device *adev;
 	bool check_children;
 	u64 addr;
 
 	check_children = pci_is_bridge(pci_dev);
 	/* Please ref to ACPI spec for the syntax of _ADR */
 	addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn);
-	return acpi_find_child_device(ACPI_COMPANION(dev->parent), addr,
+	adev = acpi_find_child_device(ACPI_COMPANION(dev->parent), addr,
 				      check_children);
+
+	/*
+	 * There may be ACPI device objects in the ACPI namespace that are
+	 * children of the device object representing the host bridge, but don't
+	 * represent PCI devices.  Both _HID and _ADR may be present for them,
+	 * even though that is against the specification (for example, see
+	 * Section 6.1 of ACPI 6.3), but in many cases the _ADR returns 0 which
+	 * appears to indicate that they should not be taken into consideration
+	 * as potential companions of PCI devices on the root bus.
+	 *
+	 * To catch this special case, disregard the returned device object if
+	 * it has a valid _HID, addr is 0 and the PCI device at hand is on the
+	 * root bus.
+	 */
+	if (adev && adev->pnp.type.platform_id && !addr &&
+	    pci_is_root_bus(pci_dev->bus))
+		return NULL;
+
+	return adev;
 }
 
 /**