Hi Peter, On Tue, May 24, 2016 at 04:27:44PM +0200, Peter Wu wrote: > @@ -246,6 +247,28 @@ static int nouveau_dsm_pci_probe(struct pci_dev *pdev) > return retval; > } > > +/* Windows 8/8.1/10 do not use DSM to put the device in D3cold state, > + * instead it disables power resources on the parent PCIe port device. */ > +static bool nouveau_check_pr3(struct pci_dev *dis_dev) > +{ > + acpi_handle parent_handle; > + struct acpi_device *ad = NULL; > + > + if (ACPI_FAILURE(acpi_get_parent(nouveau_dsm_priv.dhandle, > + &parent_handle))) { > + pr_warn("Failed to obtain the parent device\n"); > + return false; > + } > + > + acpi_bus_get_device(parent_handle, &ad); > + if (!ad) { > + pr_warn("Failed to obtain an ACPI device for handle\n"); > + return false; > + } > + > + return ad->power.flags.power_resources; > +} > + This can be shortened significantly by using pci_upstream_bridge() and ACPI_HANDLE(). Best regards, Lukas -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html