Hi! > > > - For STR, don't do the freezer thing. > > > > In the long run, I agree. > > > > Still, can you please read this post from Alan Stern: > > > > https://lists.linux-foundation.org/pipermail/linux-pm/2007-June/012847.html > > > > ? I don't think I'm able to repeat the arguments given in there in a > > convincing way. > > That's the same crackpot I've been hearing for the past 3 years or > so ... > > Both Paulus and I think the freezer is just a way to try to put your > head in the sand and ignore the problem. It causes as many problems as > it solves on its own, and is just not a solution that will be of any use > once you start implementing dynamic PM schemes etc... Well, yep, you can view freezer as a head in the sand... > In many cases, having proper support for "live" suspend of devices is > just a matter of having a couple of helpers in whatever subsystem those > drivers hookup with. In the case of network, for example, it's mostly > trivial (stop the queue). For block, it's not terribly hard neither, > though you want to have some orderign/atomicity between the blocking of > the incoming request queue and the sending of things like spindown & > flush commands to the disk. For old-style IDE, that was fairly easily > solved by piping suspend/resume command down the request queue itself > and have the queue block/unblbock itself after processing them. Some of > that logic could maybe be moved to the block layer for all block drivers > to benefit. ...but the moment you start blocking tasks that done driver request, you _do_ have mini-freezer of your own, with pretty much the same problems. In another message I shown that removing freezer will not help with FUSE in general case. It probably does not help with firmware, too; as soon as udev attempts to do something with your wireless card, it is blocked, and if the wireless card needs the firmware from udev, you are deadlocked. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
