| From: "Amit Kucheria"<kucheria.amit@xxxxxxxxx> | | On 3/21/07, Shaohua Li <shaohua.li@xxxxxxxxx> wrote: | > On Wed, 2007-03-21 at 02:30 +0800, Pavel Machek wrote: | | > > No, that's not how it works; look at hda_audio, it already has | > > powersave. Just power down audio card 5 seconds after its control file | > > is closed. | > It's another case of doing policy in a driver. | > | | IMHO, this kind of policy is best handled inside the driver because it | is specific to the hardware. This will ensure that the driver will | just work on every distro without some userspace policy being present | and setup _correctly_. --- On an embedded device, the knowledge of when it makes sense to keep a disk spinning, to avoid latency when it's needed next, versus when it makes sense to spin it down to save power, probably fits better in user space than in the kernel. In such a case there's likely to be a "master" application (in our case, for instance, "the phone application") that owns a lot of knowledge about whole-system state and user interactions. Not, of course, that we have a disk to spin down. On the other hand, we also have devices that do their own power saving, largely in cases where they don't have latency issues large enough to worry about. scott -- scott preece motorola mobile devices, il67, 1800 s. oak st., champaign, il 61820 e-mail: preece@xxxxxxxxxxxx fax: +1-217-384-8550 phone: +1-217-384-8589 cell: +1-217-433-6114 pager: 2174336114@xxxxxxxxx _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
