On Sunday, 13 of April 2008, Benjamin Herrenschmidt wrote: > > On Sun, 2008-04-13 at 15:33 +0200, Rafael J. Wysocki wrote: > > + * The PM core executes @prepare() for all devices before starting to > > + * execute suspend callbacks for any of them, so drivers may assume all of > > + * the other devices to be present and functional while @prepare() is being > > + * executed. In particular, it is safe to make GFP_KERNEL memory > > + * allocations from within @prepare(). However, drivers may NOT assume > > + * anything about the availability of the user space at that time and it > > + * is not correct to request firmware from within @prepare() (it's too > > + * late to do that). [To work around this limitation, drivers may > > + * register suspend and hibernation notifiers that are executed before the > > + * freezing of tasks.] > > Can you tell me why you kept that limitation with user space ? > > I don't see the point... On the contrary, prepare() is the pefect place > to implement handshaking with userspace for drivers that need to do so, > such as the DRM. This _comment_ reflects the current situation, which is that we freeze tasks before a suspend. When it's no longer necessary to do that, I'll be happy to change this comment. For now, however, that's not the case. Thanks, Rafael _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
