>-----Original Message----- >From: Eugeny S. Mints [mailto:eugeny.mints at gmail.com] >Sent: Thursday, July 20, 2006 12:56 PM >To: linux-pm at lists.osdl.org >Cc: Matthew Locke; toddpoynor at gmail.com; linux at dominikbrodowski.net; Gross, Mark; >igor.stoppa at nokia.com; amit.kucheria at nokia.com; sampsa.fabritius at nokia.com; r-woodruff2 at ti.com; >Mochel, Patrick >Subject: [RFC] PowerOP Take 3, sysfs UI core 2/5 > >A sysfs interface for PowerOP that allows operating points to be created >and activated from userspace. > >The platform-specific backend provides the code to read and write sysfs >attributes for each power parameter; the core sysfs interface has no >knowledge of the struct powerop_point contents. This interface could be >seen as possible extension of cpufreq sysfs. It is not >an integral part of PowerOP and is provided in part to facilitate >discussion and experimentation with PowerOP, but could serve as a basis >for a basic userspace power policy management stack. > >Operating points are created by writing the name of the operating point >to /sys/powerop/new. This may be a job for configfs. Why create a new top level sysfs entry? Can't we just put power op under /sys/devices/platform or /sys/power ? >/sys/powerop/<op>/ will contain an attribute for each power parameter >that may be written to set the associated parameter for the new >operating point. An operating point may be activated by writing its >name to /sys/powerop/active. The hardware power parameters currently >set may be read and written via /sys/powerop/hw/, a special operating >point that reads and writes parameter attribute values immediately, >primarily for diagnostic purposes. Whaaa? Is this for creating named operating points like say, full_speed, deep_idle, pay_back, ui points, that could be activated by echoing their name to /sys/powerop/active ? These aren't new points, just named existing ones. Right? >Buried in this interface is also the notion of a registry of "named >operating points", allowing operating points created by some other >interface (such as cpufreq or loading a module with the definitions as >suggested previously by David Brownell) to be activated from userspace >via /sys/powerop/active. Would it make more sense to echo "active" to the named <op> sysfs node? > >Please note that the interface is not hooked up with the rest of the code >yet and is provided just for reference/review.
