4.18-stable review patch. If anyone has any objections, please let me know.
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From: Mika Westerberg mika.westerberg@linux.intel.com
[ Upstream commit 6299cf9ec3985cac70bede8a855b5087b81a6640 ]
We enable power management automatically for bridges where pci_bridge_d3_possible() returns true. However, these bridges may have ACPI methods such as _DSW that need to be called before D3 entry. For example in Lenovo Thinkpad X1 Carbon 6th _DSW method is used to prepare D3cold for the PCIe root port hosting Thunderbolt chain. Because wake is not enabled _DSW method is never called and the port does not enter D3cold properly consuming more power than necessary.
Users can work this around by writing "enabled" to "wakeup" sysfs file under the device in question but that is not something an ordinary user is expected to do.
Since we already automatically enable power management for PCIe ports with ->bridge_d3 set extend that to enable wake for them as well, assuming the port has any ACPI wakeup related objects implemented in the namespace (adev->wakeup.flags.valid is true). This ensures the necessary ACPI methods get called at appropriate times and allows the root port in Thinkpad X1 Carbon 6th to go into D3cold.
Signed-off-by: Mika Westerberg mika.westerberg@linux.intel.com Signed-off-by: Bjorn Helgaas bhelgaas@google.com Reviewed-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/pci/pci-acpi.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-)
--- a/drivers/pci/pci-acpi.c +++ b/drivers/pci/pci-acpi.c @@ -779,19 +779,33 @@ static void pci_acpi_setup(struct device return;
device_set_wakeup_capable(dev, true); + /* + * For bridges that can do D3 we enable wake automatically (as + * we do for the power management itself in that case). The + * reason is that the bridge may have additional methods such as + * _DSW that need to be called. + */ + if (pci_dev->bridge_d3) + device_wakeup_enable(dev); + acpi_pci_wakeup(pci_dev, false); }
static void pci_acpi_cleanup(struct device *dev) { struct acpi_device *adev = ACPI_COMPANION(dev); + struct pci_dev *pci_dev = to_pci_dev(dev);
if (!adev) return;
pci_acpi_remove_pm_notifier(adev); - if (adev->wakeup.flags.valid) + if (adev->wakeup.flags.valid) { + if (pci_dev->bridge_d3) + device_wakeup_disable(dev); + device_set_wakeup_capable(dev, false); + } }
static bool pci_acpi_bus_match(struct device *dev)