On Fri, 28 May 2010, Alan Cox wrote: > If I push the button we get an IRQ > We come out of power save > The app gets poked > The app may be unimportant but the IRQ means we have a new timeout of > some form to run down to idle > The app marks itself important > The app stays awake for 60 seconds rsyncing your email > The app marks itself unimportant > Time elapses > We return to suspend > > > If you are absolutely utterly paranoid about it you need the button > driver to mark the task it wakes back as important rather than rely on > time for response like everyone else. That specific bit is uggglly but > worst case its just a google private patch to a few drivers. I understand > why Android wants it. The narrower the gap between 'we are doing nothing, > sit in lowest CPU on state' and 'we are off' the better the battery life > and the more hittable the condition. That "private patch to a few drivers" is almost exactly what suspend blockers are. Given that much of this discussion has revolved around whether suspend blockers are accptable in the kernel, I don't think you should shrug them off quite so easily. Also, you have forgotten about the case where there is no app waiting to get poked: The app is busy doing something else unimportant We do into power save Push a button, generate an IRQ Come out of power save No app to poke * System goes back to sleep and eventually wakes up again The app finishes what it was doing The app sees there is a keystroke and marks itself important ... The * step is where trouble can occur. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
