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

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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 fe31e69740 ("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
fe31e69740 (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>
This commit is contained in:
Bjorn Helgaas 2018-03-09 11:06:55 -06:00 committed by Bjorn Helgaas
parent a39bd851dc
commit 3620c71484
1 changed files with 2 additions and 1 deletions
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3
drivers/pci/pci-driver.c
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@ -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);
}