On Sat, 2005-04-09 at 17:25 +1000, Cedric Pradalier wrote: > According to Tamas K Papp, on Fri, 8 Apr 2005 23:24:22 -0400, > >On Fri, Apr 08, 2005 at 11:05:36PM -0400, Tamas K Papp wrote: > > > >> Thanks for your help. I compiled a 2.6.12-rc2 kernel and I am happy > >> to share that sleep now works on my powerbook5,4: the machine sleeps > >> perfectly, wakes up perfectly, and usb devices are powered up every > >> time. I will test it more tomorrow, but it seems very sound. > > > >OK, that was a bit premature ;-) I already found a glitch: if I > >generate an USB event (eg click the buttons on the mouse) while the > >machine is sleeping, it will try to wake up but the screen remains > >blank. If somebody on this list is on the kernel list too, and they > >don't know already about this, please forward this (but I expect that > >they would). > > > > Just a side comment on that. > > For me this means that all the usb devices are still powered when the machine > is asleep. > They can indeed consume a lot of energy and greatly reduce battery life. > > I think I'll continue to unload/reload all the module, except if there is an > option > telling the modules to switch the USB system off completely when going to > sleep.
It is not a good idea. If you unload the OHCI or EHCI module during sleep, the controller will not be put to sleep _at_all_ The USB standard specifies a specific "suspended" state that is using during machine sleep. In this state, only a little bit of power is provided to the bus, enough to let some USB devices to trigger a wakeup. The kernel drivers do suspend the root hubs. Ben. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
