On Fri, Jun 26, 2009 at 09:23:12AM -0700, Kok, Auke wrote: > Alberto Gonzalez wrote: > > Thanks for the link. Interestingly Matthew Garrett says there that powertop > > is > > actually doing it in the wrong way (USB autosuspend), so maybe this is a > > bug > > in powertop (bug in the sense of using a wrong/old implementation)? > > Matthew knows where to find me and how to write patches, so I assume he's got > something coming for me then...
To be honest, most of my work in this field has been trying to ensure that we can just remove all the hints from powertop :) It used to be that powertop just read the autosuspend file to check whether autosuspend was enabled - that seems to have been fixed now, but it still suggests booting with "usbcore.autosuspend=1" to enable autosuspend. That only changes the default delay, it doesn't actually enable it. There's no general kernel option to enable autosuspend, mostly because whether you want it or not is a somewhat difficult question. As the original poster noted, enabling autosuspend on input devices will generally result in unhappiness - many keyboards will drop the first keystroke, and mice will only wake up in response to a button press and not movement. > That's the file that powertop touches when you press 'U'. powertop also sets > power/level to "auto", meaning the kernel can suspend/resume the device when > it > wants. > > if someone has patches on how to improve this, I'll gladly take them... I'd actually suggest that powertop stop making this suggestion. The kernel and userspace will be updated as hardware is verified, but there's no real way powertop itself can decide whether it's safe to enable USB autosuspend or not. -- Matthew Garrett | [email protected] _______________________________________________ Power mailing list [email protected] http://www.bughost.org/mailman/listinfo/power
