On Tuesday 14 November 2006 1:42 pm, Alan Stern wrote: > On Tue, 14 Nov 2006, David Brownell wrote: > > > On Monday 13 November 2006 9:15 am, Alan Stern wrote: > > > On Mon, 13 Nov 2006, David Brownell wrote: > > > > > > > It's a *driver model* API, which is also accessible from sysfs ... to > > > > support > > > > per-device policies, for example the (a) workaround. The mechanism > > > > exists > > > > even on kernels that don't include sysfs ... although on such systems, > > > > there > > > > is no way for users to do things like say "ignore the fact that this > > > > mouse > > > > claims to issue wakeup events, its descriptors lie". > > > > > > Yes, it is separate from sysfs -- but it is _tied_ to the sysfs API. > > > > I can't agree. If you deconfigure sysfs, it still works. > > Since it's independent like that, there's no way it's "tied". > > We could carry on this argument indefinitely. Yes, the device_may_wakeup > stuff does work without sysfs. But it doesn't do anything significant; it > amounts to no more than device_can_wakeup(). AFAIK there's no way to > change the setting of the may_wakeup flag other than via sysfs. That's > what I meant by "tied".
So "tied" means "nobody has yet needed to create a different API for that subset of the mechanism"? Still can't agree. Nothing's preventing anyone from creating such an API, if they need to. > > So "may" is correct, and "can" is insufficient. > > Things work differently in uhci-hcd. They shouldn't. That's the point of having this in the driver model: so that all wakeup-capable devices can/will act the same in terms of the basic capability and policy. (Of course, there are ugly PPC/OF-only enumeration issues that keep us from kicking in the wakeup mechanisms for PCI devices. But that's a separate issue, specific to PCI ... although it sucks hugely, since so few developers have non-PCI wakeup-capable devices.) > However even when it is added and may_wakeup is off, autostop will still > function. It won't rely on interrupts or other wakeup events, though -- > instead the root-hub status polling mechanism will be used. Well, as was said previously: For UHCI it's not "just" a PM mechanism. - Dave ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
