On Monday, 14 of April 2008, Alan Stern wrote: > On Mon, 14 Apr 2008, Nigel Cunningham wrote: > > > > The ability for prepare() callbacks to sync with userland, > > > request_firmware, etc... is an important feature that's been needed for > > > some time imho. > > > > > > Ben. > > > > I agree. These calls have already been changing far too often in > > mainline. I know it's all been necessary but please, can we try to make > > one set of changes and just get it right this time? > > In practical terms, it will be easier to keep the freezer where it is > for now. This is because prepare() requires drivers to change their > behavior; they aren't allowed to register new children any more. > > But if userspace isn't frozen then user programs can interact with > drivers in a way that does cause new children to be created. For > example this happens in USB, where opening an audio device and > selecting its bitrate causes a new set of endpoints to be realized, > along with their representations in sysfs. > > Thus, in addition to making all the interface changes implied by the > new callbacks, drivers would also have to change the way they interact > with userspace. Yes, this will have to be done eventually in any case, > as the freezer goes away -- but it shouldn't have to be done right now. That's exactly my point. Plus in my opinion, while with ->prepare() after the freezer it's possible to write ->prepare() and ->suspend() that will work just fine when we remove the freezer, with ->prepare() before the freezer it would be hard to do that, unless ->prepare() was trivial. Thanks, Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
