On Wed, 8 Jan 2014, Alan Stern wrote: > In essence, you want your disk's state to move directly from unpowered > (system asleep) to runtime-suspended with no intermediate active -- but > only if the disk doesn't spin up all by itself. > In the end, it sounds like what you want can be done fairly easily. It turns out there is a snag. The PM core is set up such that during system sleep transitions, there's no way to tell whether or not userspace has permitted runtime PM for a device. (This is because the core wants to prevent untimely runtime suspends from occurring in the middle of a system sleep transition, and to do so it uses the same mechanism as it does when userspace disallows runtime suspend.) As a result, we must not go directly from unpowered to runtime-suspended. Not without some sort of change to the PM core. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
