On Mon, 29 Nov 2004, Benjamin Herrenschmidt wrote: > Didn't we discuss already the fact that this mix of selective & system > suspend was totally unacceptable and should be split in different > calls ? We _MUST_ provide different selectors to suspend() if we ever > want to really support selective suspend (the current stuff or writing a > random number to /sys/*/power/state is crap). This must be resolved. As things stand the USB subsystem has only a single suspend() callback for device drivers, with no way to distinguish between selective and system suspend. Adding proper support for selective suspend will be very important for the future development of Linux in low-power environments. We need to get it correct from the start. Should SELECTIVE_SUSPEND be added as a PM message type? Then calls through sysfs (whatever form they end up taking) would pass that message rather than SYSTEM_SUSPEND. I'm not sure how the USB framework should be changed. Alan Stern
