On Monday 07 December 2009, Linus Torvalds wrote: > > On Mon, 7 Dec 2009, Rafael J. Wysocki wrote: > > > > > The advantage: untouched drivers don't change ANY SEMANTICS AT ALL. > > > > This also was true for my patchset. > > That's simply not trye. > > You set async_suspend on every single PCI driver. I object very heavily to > it. That was a mistake, I admit. However, it was done in a separate patch that (1) was not necessary and (2) shouldn't have been there. Sorry for making the mistake of including that into the patchset. So I understand your objection to that and let's not get back to this again, ok? > You also introduce this whole big "callback when ready", and > "non-topoligical PM dependency chain" thing. Which I also object to. These things are also non-essential. Acutally they wasn't there in the initial version of my patches and were added after people had complained that it had not been parallel enough and hadn't take the off-tree dependecies into account. I could remove these things either and quite easily. > Notice how with the simpler "lock parent" model, you _can_ actually encode > non-topological dependencies, but you do it by simply read-locking > whatever other independent device you want. So if an architecture has some > system devices that have odd rules, that architecture can simply encode > those rules in its suspend() functions. I'm not arguing against that. In fact, my only worry were that additional suspend/resume callbacks I really wouldn't like to introduce. But since you've found a way of doing things without them, I'm totally fine with this approach. > It doesn't need to expose it to the device layer - because the device > layer won't even care. The code will just automatically "do the right > thing" without even having that notion of PM dependencies at any other > level than the driver that knows about it. > > No registration, no callbacks, no nothing. > > > In my patchset the drivers didn't need to do all that stuff. The only thing > > they needed, if they wanted their suspend/resume to be executed > > asynchronously, was to set the async_suspend flag. > > In my patchset, the drivers don't need to either. > > The _only_ thing that would do this is something like the USB layer. We're > talking ten lines of code or so. And you get rid of all the PM > dependencies and all the infrastructure - because the model is so simple > that it doesn't need any. It just uses a different way of representing these things, perhaps more efficiently. > (Well, except for the infrastructure to run things asynchronously, but > that was kind of my point from the very beginning: we can just re-use all > that existing async infrastructure. We already have that). So I guess the only thing we need at the core level is to call async_synchronize_full() after every stage of suspend/resume, right? 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
