Commit 3620c714 authored Mar 09, 2018 by Bjorn Helgaas Committed by Bjorn Helgaas Mar 30, 2018

PCI/PM: Clear PCIe PME Status bit for Root Complex Event Collectors



Per PCIe r4.0, sec 6.1.6, Root Complex Event Collectors can generate PME
interrupts on behalf of Root Complex Integrated Endpoints.

Linux does not currently enable PME interrupts from RC Event Collectors,
but fe31e697 ("PCI/PCIe: Clear Root PME Status bits early during system
resume") suggests PME interrupts may be enabled by the platform for ACPI-
based runtime wakeup.

Clear the PCIe PME Status bit for Root Complex Event Collectors during
resume, just like we already do for Root Ports.

If the BIOS enables PME interrupts for an event collector and neglects to
clear the status bit on resume, this change should fix the same bug as
fe31e697 (PMEs not working after waking from a sleep state), but for
Root Complex Integrated Endpoints.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

parent a39bd851

drivers/pci/pci-driver.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -722,7 +722,8 @@ static void pcie_pme_root_status_cleanup(struct pci_dev *pci_dev)
		* Clear those bits now just in case (shouldn't hurt).
		*/
		if (pci_is_pcie(pci_dev) &&
		pci_pcie_type(pci_dev) == PCI_EXP_TYPE_ROOT_PORT)
		(pci_pcie_type(pci_dev) == PCI_EXP_TYPE_ROOT_PORT \|\|
		pci_pcie_type(pci_dev) == PCI_EXP_TYPE_RC_EC))
		pcie_clear_root_pme_status(pci_dev);
		}

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