On Monday 16 February 2009, Arjan van de Ven wrote: > On Mon, 16 Feb 2009 22:48:32 +0100 > "Rafael J. Wysocki" <rjw@xxxxxxx> wrote: > > > > Userland should never ever control the state of a device like this > > > directly. It should do so by a) closing the device and b) setting > > > latency / functional requirements. > > > > The user, however, may want to forcibly put a device into a low power > > state without stopping all of the applications that depend on it (eg. > > have it open). Do you think that we shouldn't allow users to do such > > things? > > I would think that that is a bad mistake to do. It basically breaks the > contract that the kernel has with userspace.... OK, so I think there are two things that user space may be allowed to do as far as putting devices into low power states is concerned: * disable/enable the automatic power management of the device (provided that the driver supports the automatic PM) * check what power states devices are in. Thanks, Rafael _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
