On Tuesday 17 July 2007, Rafael J. Wysocki wrote: > In the future some drivers may need to use ACPI to determine the low power > states in which to place their devices, but to provide the drivers with this > information the ACPI core needs to know what sleep state the system is going > to > enter. Namely, the device's state should not be too high power for given > system > sleep state and, if the device is supposed to be able to wake up the system, > its > state should not be too low power for the wake up to be possible). For this > purpose, the ACPI core needs to implement the set_target() method in 'struct > pm_ops' and store the target system sleep state passed by the PM core in a > variable.
Modulo Len's "please remove non-existent S2 state", ACK. We still have a general issue that most platforms implement at most one of the sleep states the hardware allows (plus, sometimes, hibernation). A key differentiator of those different sleep states is usually that they have characteristics which allow various devices to work, or not. Like, oh, USB controllers which need a 48 MHz oscillator to process wakeup events ... but the deepest sleep states must disable that oscillator. So it's a Good Thing that this patch (and #2) expose that more complete model of system sleep states to drivers running on x86. - Dave - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
