On Thu, 8 Mar 2012, Kevin Hilman wrote: > "Rafael J. Wysocki" <rjw@xxxxxxx> writes: > > > From: Rafael J. Wysocki <rjw@xxxxxxx> > > > > A runtime suspend of a device (e.g. an MMC controller) belonging to > > a power domain or, in a more complicated scenario, a runtime suspend > > of another device in the same power domain, may cause power to be > > removed from the entire domain. In that case, the amount of time > > necessary to runtime-resume the given device (e.g. the MMC > > controller) is often substantially greater than the time needed to > > run its driver's runtime resume callback. That may hurt performance > > in some situations, because user data may need to wait for the > > device to become operational, so we should make it possible to > > prevent that from happening. > > > > For this reason, introduce a new sysfs attribute for devices, > > power/pm_qos_latency_us, allowing user space to specify the upper > > If we're expecting to have more of these knobs, maybe having a pm_qos > subdir under power will keep down the clutter in /sys/devices/.../power. > This knob would then be /sys/devices/.../power/pm_qos/pm_qos_latency_us. If this change does have to be made, I'd propose .../power/qos/latency... removing redundancy. Thanks Guennadi --- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer http://www.open-technology.de/ -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
