> What is a "Correctly implemented driver" in this case? One that receives > a wakeup event and then prevents suspend being entered until userspace > has acknowledged that event? Because that's what an in-kernel suspend > blocker is. Kernel side maybe - but even then its a subset of expressing latency/lowest level requirements. That bit isn't really too contentious. You need a kernel object to hang a constraint off. > ACPI provides no guarantees about what level of hardware functionality > remains during S3. You don't have any useful ability to determine which > events will generate wakeups. And from a purely practical point of view, > since the latency is in the range of seconds, you'll never have a low > enough wakeup rate to hit it. So PCs with current ACPI don't get opportunistic suspend capability. It probably won't be supported on the Commodore Amiga either - your point ? > Suspend blockers are the mechanism for the > driver to indicate whether the wakeup event has been handled. That's > what they're there for. The in-kernel ones don't paper over anything. Semantically the in kernel blockers and the in kernel expression of device driven constraints are the same thing except that instead of yes/no you replace the boolean with information. So we go from block_suspend() / unblock_suspend() to add_pm_constraint(latency, level) remove_pm_constraint(latency, level); And if Android choses to interpret that in its policy code as if (latency > MAGIC) suspend_is_cool(); else suspend_isnt_cool(); that's now isolated in droidspace policy Alan _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
