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PCI: PM: Avoid skipping bus-level PM on platforms without ACPI

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There are platforms that do not call pm_set_suspend_via_firmware(),
so pm_suspend_via_firmware() returns 'false' on them, but the power
states of PCI devices (PCIe ports in particular) are changed as a
result of powering down core platform components during system-wide
suspend.  Thus the pm_suspend_via_firmware() checks in
pci_pm_suspend_noirq() and pci_pm_resume_noirq() introduced by
commit 3e26c5feed ("PCI: PM: Skip devices in D0 for suspend-to-
idle") are not sufficient to determine that devices left in D0
during suspend will remain in D0 during resume and so the bus-level
power management can be skipped for them.

For this reason, introduce a new global suspend flag,
PM_SUSPEND_FLAG_NO_PLATFORM, set it for suspend-to-idle only
and replace the pm_suspend_via_firmware() checks mentioned above
with checks against this flag.

Fixes: 3e26c5feed ("PCI: PM: Skip devices in D0 for suspend-to-idle")
Reported-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
This commit is contained in:
Rafael J. Wysocki
2019-06-26 00:20:23 +02:00
parent 4b972a01a7
commit 471a739a47
3 changed files with 31 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

8
drivers/pci/pci-driver.c
View File

@@ -859,7 +859,7 @@ static int pci_pm_suspend_noirq(struct device *dev)
pci_dev->bus->self->skip_bus_pm = true;
}
if (pci_dev->skip_bus_pm && !pm_suspend_via_firmware()) {
if (pci_dev->skip_bus_pm && pm_suspend_no_platform()) {
dev_dbg(dev, "PCI PM: Skipped\n");
goto Fixup;
}
@@ -914,10 +914,10 @@ static int pci_pm_resume_noirq(struct device *dev)
/*
* In the suspend-to-idle case, devices left in D0 during suspend will
* stay in D0, so it is not necessary to restore or update their
* configuration here and attempting to put them into D0 again may
* confuse some firmware, so avoid doing that.
* configuration here and attempting to put them into D0 again is
* pointless, so avoid doing that.
*/
if (!pci_dev->skip_bus_pm || pm_suspend_via_firmware())
if (!(pci_dev->skip_bus_pm && pm_suspend_no_platform()))
pci_pm_default_resume_early(pci_dev);
pci_fixup_device(pci_fixup_resume_early, pci_dev);