There's been some discussion about limitations of the current pmcore for systems that want to be partially suspended most of the time. That is, where the power management needs to affect ACPI G0 states, not G1 states like S1/S3/S4, and isn't cpufreq.
One significant example involves USB mice. If they were to be suspended (usb_suspend_device) after a few seconds of inactivity, that change could often spread up the device tree and let the USB host controller stop DMA access. Some x86 CPUs could then enter C3 and save a couple Watts of battery power ... until the mouse moved, and woke that branch of the device tree for a while (until the mouse went idle again). Most of the parts for that are now in place. But trying to use them will turn up places where the pieces don't fit together very well yet ... and wakeup support is one of them! So for example it's not possible to disable such an autosuspend mechanism for mice that can't actually issue wakeups. So here are a few patches that add some driver model support for wakeup capabilities, and use it for PCI and USB. - wake-core.patch, adds two bits and sysfs control over one of them - wake-pci.patch, makes pci use those bits - wake-usbcore.patch, makes usb do so (replacing code/hacks) - wake-ohci.patch, matching wake-usbcore The patches follow this, going to LKML. Comments? - Dave ------------------------------------------------------- This SF.net email is sponsored by: IT Product Guide on ITManagersJournal Use IT products in your business? Tell us what you think of them. Give us Your Opinions, Get Free ThinkGeek Gift Certificates! Click to find out more http://productguide.itmanagersjournal.com/guidepromo.tmpl _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
