> I've recently discovered that pci_set_power_state() calls the platform > callback intended for changing the state of the device after it has done > that using the native PCI mechanism. In my opinion this is not correct, > because, for example, if the device is being put into D0 from a low power > state, it may require some platform-controlled power resources to be turned > on before that (in theory). > > The following series of patches changes this function so that the platform > callback is performed first and then the native mechanism is used. > Additionally, however, it checks if the devices is power manageable by the > platform and only in that case the platform callback is invoked. For this > purpose, I needed to add an ACPI function allowing PCI to check the power > manageability of given device. We have 3 cases 1. device has PCI PM only 2. device has ACPI PM only 3. device has both PCI and ACPI PM For #1 and #2, order is moot. For #3, how can we be sure that the new order is better than the old order? Is this a theoretical patch, or is there a failure case? thanks, -Len _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
