> > > It [device idle attribute] also means that the device is in > > > some "good" state from which the driver can go back to normal operation, > > > even if the device has lost power in the meantime. > > > > That "even if the device has lost power" would be a major > > malfunction if it weren't accompanied by a power state > > transition. It's a requirement for certain resume() transitions, > > but otherwise ... not IMO a good idea. > > But it's unavoidable that drivers will encounter devices that have lost > power when resuming from the "idle" state -- and with no intervening power > state transition -- if power isn't available (not even suspend power) > while the system is off.
That's why I said "accompanied by a power state transition". Like turning the system off, or otherwise reducing power input; and then issuing resume() calls. But if there was no power state transition, hence no resume(), then a device losing power means a major hardware problem. > What about Oliver's objection that support for wakeup depends on the > power level? Like he said, it's easier just to try turning on wakeup and > see if you get a "not-supported" error. That's why I specified one bit controlling whether or not the device should try to enable wakeup when it changes into a suspend state. That copes with PCI restrictions, but doesn't try to export them anywhere else (like to USB). > > I suspect that it [PME#] goes to some > > ACPI "embedded controller", which either... > > Have you tried asking about this on the ACPI mailing list? Yes, no information was forthcoming. It's maybe more of a PCI PM issue. And in any case, it's clear that from the PCI perspective it's just another signal ... heck, you could even just poll the PME# status of PCI devices in some timer thread, if ACPI (or whatever) wasn't happy providing more efficient notifications. - Dave ------------------------------------------------------- This SF.net email is sponsored by: IT Product Guide on ITManagersJournal Use IT products in your business? Tell us what you think of them. Give us Your Opinions, Get Free ThinkGeek Gift Certificates! Click to find out more http://productguide.itmanagersjournal.com/guidepromo.tmpl _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
