Commit a39bd851 authored by Bjorn Helgaas's avatar Bjorn Helgaas
Browse files

PCI/PM: Clear PCIe PME Status bit in core, not PCIe port driver 

fe31e697 ("PCI/PCIe: Clear Root PME Status bits early during system
resume") added a .resume_noirq() callback to the PCIe port driver to clear
the PME Status bit during resume to work around a BIOS issue.

The BIOS evidently enabled PME interrupts for ACPI-based runtime wakeups
but did not clear the PME Status bit during resume, which meant PMEs after
resume did not trigger interrupts because PME Status did not transition
from cleared to set.

The fix was in the PCIe port driver, so it worked when CONFIG_PCIEPORTBUS
was set.  But I think we *always* want the fix because the platform may use
PME interrupts even if Linux is built without the PCIe port driver.

Move the fix from the port driver to the PCI core so we can work around
this "PME doesn't work after waking from a sleep state" issue regardless of
CONFIG_PCIEPORTBUS.

[bhelgaas: folded in warning fix from Arnd Bergmann <arnd@arndb.de>:
https://lkml.kernel.org/r/20180328134747.2062348-1-arnd@arndb.de

]
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
parent dcb0453d

drivers/pci/pci-driver.c

+13 −0
Original line number Diff line number Diff line
@@ -714,6 +714,17 @@ static void pci_pm_complete(struct device *dev) 
#endif /* !CONFIG_PM_SLEEP */



#ifdef CONFIG_SUSPEND

static void pcie_pme_root_status_cleanup(struct pci_dev *pci_dev)

{

	/*

	 * Some BIOSes forget to clear Root PME Status bits after system

	 * wakeup, which breaks ACPI-based runtime wakeup on PCI Express.

	 * 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)

		pcie_clear_root_pme_status(pci_dev);

}



static int pci_pm_suspend(struct device *dev)

{
@@ -873,6 +884,8 @@ static int pci_pm_resume_noirq(struct device *dev) 
	if (pci_has_legacy_pm_support(pci_dev))

		return pci_legacy_resume_early(dev);



	pcie_pme_root_status_cleanup(pci_dev);



	if (drv && drv->pm && drv->pm->resume_noirq)

		error = drv->pm->resume_noirq(dev);

drivers/pci/pcie/portdrv_pci.c

+0 −15
Original line number Diff line number Diff line
@@ -61,20 +61,6 @@ static int pcie_portdrv_restore_config(struct pci_dev *dev) 
}



#ifdef CONFIG_PM

static int pcie_port_resume_noirq(struct device *dev)

{

	struct pci_dev *pdev = to_pci_dev(dev);



	/*

	 * Some BIOSes forget to clear Root PME Status bits after system wakeup

	 * which breaks ACPI-based runtime wakeup on PCI Express, so clear those

	 * bits now just in case (shouldn't hurt).

	 */

	if (pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT)

		pcie_clear_root_pme_status(pdev);

	return 0;

}



static int pcie_port_runtime_suspend(struct device *dev)

{

	return to_pci_dev(dev)->bridge_d3 ? 0 : -EBUSY;
@@ -102,7 +88,6 @@ static const struct dev_pm_ops pcie_portdrv_pm_ops = { 
	.thaw		= pcie_port_device_resume,

	.poweroff	= pcie_port_device_suspend,

	.restore	= pcie_port_device_resume,

	.resume_noirq	= pcie_port_resume_noirq,

	.runtime_suspend = pcie_port_runtime_suspend,

	.runtime_resume	= pcie_port_runtime_resume,

	.runtime_idle	= pcie_port_runtime_idle,

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