If a PCI driver leaves the device handled by it in D0 and calls
pci_save_state() on the device in its ->suspend() or ->suspend_late()
callback, it can expect the device to stay in D0 over the whole
s2idle cycle.  However, that may not be the case if there is a
spurious wakeup while the system is suspended, because in that case
pci_pm_suspend_noirq() will run again after pci_pm_resume_noirq()
which calls pci_restore_state(), via pci_pm_default_resume_early(),
so state_saved is cleared and the second iteration of
pci_pm_suspend_noirq() will invoke pci_prepare_to_sleep() which
may change the power state of the device.

To avoid that, add a new internal flag, skip_bus_pm, that will be set
by pci_pm_suspend_noirq() when it runs for the first time during the
given system suspend-resume cycle if the state of the device has
been saved already and the device is still in D0.  Setting that flag
will cause the next iterations of pci_pm_suspend_noirq() to set
state_saved for pci_pm_resume_noirq(), so that it always restores the
device state from the originally saved data, and avoid calling
pci_prepare_to_sleep() for the device.

Fixes: 33e4f80ee69b ("ACPI / PM: Ignore spurious SCI wakeups from suspend-to-idle")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

Both acpi_pci_need_resume() and acpi_dev_needs_resume() check if the
current ACPI wakeup configuration of the device matches what is
expected as far as system wakeup from sleep states is concerned, as
reflected by the device_may_wakeup() return value for the device.

However, they only should do that if wakeup.flags.valid is set for
the device's ACPI companion, because otherwise the wakeup.prepare_count
value for it is meaningless.

Add the missing wakeup.flags.valid checks to these functions.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

Pull PCI updates from Bjorn Helgaas:
 "Enumeration changes:

   - Add _HPX Type 3 settings support, which gives firmware more
     influence over device configuration (Alexandru Gagniuc)

   - Support fixed bus numbers from bridge Enhanced Allocation
     capabilities (Subbaraya Sundeep)

   - Add "external-facing" DT property to identify cases where we
     require IOMMU protection against untrusted devices (Jean-Philippe
     Brucker)

   - Enable PCIe services for host controller drivers that use managed
     host bridge alloc (Jean-Philippe Brucker)

   - Log PCIe port service messages with pci_dev, not the pcie_device
     (Frederick Lawler)

   - Convert pciehp from pciehp_debug module parameter to generic
     dynamic debug (Frederick Lawler)

  Peer-to-peer DMA:

   - Add whitelist of Root Complexes that support peer-to-peer DMA
     between Root Ports (Christian König)

  Native controller drivers:

   - Add PCI host bridge DMA ranges for bridges that can't DMA
     everywhere, e.g., iProc (Srinath Mannam)

   - Add Amazon Annapurna Labs PCIe host controller driver (Jonathan
     Chocron)

   - Fix Tegra MSI target allocation so DMA doesn't generate unwanted
     MSIs (Vidya Sagar)

   - Fix of_node reference leaks (Wen Yang)

   - Fix Hyper-V module unload & device removal issues (Dexuan Cui)

   - Cleanup R-Car driver (Marek Vasut)

   - Cleanup Keystone driver (Kishon Vijay Abraham I)

   - Cleanup i.MX6 driver (Andrey Smirnov)

  Significant bug fixes:

   - Reset Lenovo ThinkPad P50 GPU so nouveau works after reboot (Lyude
     Paul)

   - Fix Switchtec firmware update performance issue (Wesley Sheng)

   - Work around Pericom switch link retraining erratum (Stefan Mätje)"

* tag 'pci-v5.2-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (141 commits)
  MAINTAINERS: Add Karthikeyan Mitran and Hou Zhiqiang for Mobiveil PCI
  PCI: pciehp: Remove pointless MY_NAME definition
  PCI: pciehp: Remove pointless PCIE_MODULE_NAME definition
  PCI: pciehp: Remove unused dbg/err/info/warn() wrappers
  PCI: pciehp: Log messages with pci_dev, not pcie_device
  PCI: pciehp: Replace pciehp_debug module param with dyndbg
  PCI: pciehp: Remove pciehp_debug uses
  PCI/AER: Log messages with pci_dev, not pcie_device
  PCI/DPC: Log messages with pci_dev, not pcie_device
  PCI/PME: Replace dev_printk(KERN_DEBUG) with dev_info()
  PCI/AER: Replace dev_printk(KERN_DEBUG) with dev_info()
  PCI: Replace dev_printk(KERN_DEBUG) with dev_info(), etc
  PCI: Replace printk(KERN_INFO) with pr_info(), etc
  PCI: Use dev_printk() when possible
  PCI: Cleanup setup-bus.c comments and whitespace
  PCI: imx6: Allow asynchronous probing
  PCI: dwc: Save root bus for driver remove hooks
  PCI: dwc: Use devm_pci_alloc_host_bridge() to simplify code
  PCI: dwc: Free MSI in dw_pcie_host_init() error path
  PCI: dwc: Free MSI IRQ page in dw_pcie_free_msi()
  ...

  - Cleanup PCI register definitions, typos, etc (Bjorn Helgaas)

  - Remove unnecessary use of user-space types in CPER (Bjorn Helgaas)

  - Cleanup setup-bus.c comments & whitespace (Nicholas Johnson)

* pci/trivial:
  PCI: Cleanup setup-bus.c comments and whitespace
  CPER: Remove unnecessary use of user-space types
  CPER: Add UEFI spec references
  PCI: Fix comment typos
  PCI: Cleanup register definition width and whitespace

# Conflicts:
#	drivers/pci/pci.c
#	drivers/pci/setup-bus.c

  - Change some desirable KERN_DEBUG messages to KERN_INFO/KERN_ERR
    (Frederick Lawler)

  - Log PCIe port service messages with pci_dev, not the pcie_device
    (Frederick Lawler)

  - Convert pciehp from pciehp_debug module parameter to generic dynamic
    debug (Frederick Lawler)

* pci/printk-portdrv:
  PCI: pciehp: Remove pointless MY_NAME definition
  PCI: pciehp: Remove pointless PCIE_MODULE_NAME definition
  PCI: pciehp: Remove unused dbg/err/info/warn() wrappers
  PCI: pciehp: Log messages with pci_dev, not pcie_device
  PCI: pciehp: Replace pciehp_debug module param with dyndbg
  PCI: pciehp: Remove pciehp_debug uses
  PCI/AER: Log messages with pci_dev, not pcie_device
  PCI/DPC: Log messages with pci_dev, not pcie_device
  PCI/PME: Replace dev_printk(KERN_DEBUG) with dev_info()
  PCI/AER: Replace dev_printk(KERN_DEBUG) with dev_info()

* pci/printk:
  PCI: Replace dev_printk(KERN_DEBUG) with dev_info(), etc
  PCI: Replace printk(KERN_INFO) with pr_info(), etc
  PCI: Use dev_printk() when possible

  - Add list of legal DMA address ranges to PCI host bridge (Srinath
    Mannam)

  - Reserve inaccessible DMA ranges so IOMMU doesn't allocate them (Srinath
    Mannam)

  - Parse iProc DT dma-ranges to learn what PCI devices can reach via DMA
    (Srinath Mannam)

* pci/iova-dma-ranges:
  PCI: iproc: Add sorted dma ranges resource entries to host bridge
  iommu/dma: Reserve IOVA for PCIe inaccessible DMA address
  PCI: Add dma_ranges window list

# Conflicts:
#	drivers/pci/probe.c

  - Exit pcitest with error code when test fails (Jean-Jacques Hiblot)

  - Fix leaked of_node references in dra7xx, uniphier, layerscape,
    rockchip, aardvark, iproc, mediatek, rpadlpar (Wen Yang)

  - Fix pcitest "help" option parsing (Kishon Vijay Abraham I)

  - Fix Makefile bug that inadvertently removes pcitest.sh (Kishon Vijay
    Abraham I)

  - Check for alloc_workqueue() failure in endpoint test driver (Kangjie
    Lu)

* remotes/lorenzo/pci/misc:
  PCI: endpoint: Fix a potential NULL pointer dereference
  tools: PCI: Handle pcitest.sh independently from pcitest
  tools: PCI: Add 'h' in optstring of getopt()
  PCI: mediatek: Fix a leaked reference by adding missing of_node_put()
  PCI: iproc: Fix a leaked reference by adding missing of_node_put()
  PCI: aardvark: Fix a leaked reference by adding missing of_node_put()
  PCI: rockchip: Fix a leaked reference by adding missing of_node_put()
  PCI: dwc: layerscape: Fix a leaked reference by adding missing of_node_put()
  PCI: uniphier: Fix a leaked reference by adding missing of_node_put()
  PCI: dwc: pci-dra7xx: Fix a leaked reference by adding missing of_node_put()
  tools: PCI: Exit with error code when test fails

  - Check for __get_free_pages() failure in xilinx (Kangjie Lu)

* remotes/lorenzo/pci/xilinx:
  PCI: xilinx: Check for __get_free_pages() failure

  - Use DMA-API to get tegra MSI address to prevent device DMA from
    generating unwanted MSIs (Vidya Sagar)

* remotes/lorenzo/pci/tegra:
  PCI: tegra: Use the DMA-API to get the MSI address