On Friday, November 02, 2012 01:17:10 PM Aaron Lu wrote: > On 10/30/2012 11:20 PM, Rafael J. Wysocki wrote: > > On Tuesday, October 30, 2012 03:28:45 PM Aaron Lu wrote: > >> On Mon, Oct 29, 2012 at 10:11:20AM +0100, Rafael J. Wysocki wrote: > >>> From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > >>> > >>> If the caller of acpi_bus_set_power() already has a pointer to the > >>> struct acpi_device object corresponding to the device in question, it > >>> doesn't make sense for it to go through acpi_bus_get_device(), which > >>> may be costly, because it involves acquiring the global ACPI > >>> namespace mutex. > >>> > >>> For this reason, export the function operating on struct acpi_device > >>> objects used internally by acpi_bus_set_power(), so that it may be > >>> called instead of acpi_bus_set_power() in the above case, and change > >>> its name to acpi_device_set_power(). > >>> > >>> Additionally, introduce two inline wrappers for checking ACPI PM > >>> capabilities of devices represented by struct acpi_device objects. > >> > >> What about adding yet another wrapper to check power off capability of > >> the device? If device has _PS3 or _PRx, it means the device can be > >> powered off from ACPI's perspective. This is useful for ZPODD when > >> deciding if platform has the required ability to support it. > > > > Sure, no problem with that. Perhaps you can cut a patch for that > > on top of this series? > > Do you think it is reasonable to add a new field to acpi_state.flags to > represent if we, as OSPM, have a way to put the device into a ACPI > device state? This field can be set once in acpi_bus_get_power_flags and > used afterwards. > > The valid field of acpi_state.flags is what we have today, and it means > whether this ACPI device state is valid for the device, but not that if > OSPM can actually put the device into that power state. Yes, I think that adding such a new flag would make sense. Thanks, Rafael -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
