* Rafael J. Wysocki <rjw@xxxxxxxxxxxxx> [171108 00:25]: > On Tuesday, November 7, 2017 5:00:06 PM CET Tony Lindgren wrote: > > For runtime PM, restoring the state constantly is unnecessary and not > > good for battery life. The logic can be just: > > > > 1. Device driver runtime PM suspend saves the state when needed > > > > 2. Device driver runtime PM resume checks if context_lost was set by > > the bus or power domain code > > > > 3. If context was lost, device driver restores the state, or in some > > cases may need re-run the driver register init related parts > > to bring the driver back up, then clears the context_lost flag > > > > How about something like the following patch? So far only compile > > tested with CONFIG_PM enabled. If that looks like the way to go, > > I'll test it properly and add some comments for the functions and > > post a proper patch :) > > Honestly, I'm not sure. > > I'd rather have a context_lost flag to start with and see how/if > drivers will use that before adding any common infra for handling > this. Right, I'll provide some use cases but it will be a little while. Currently it's done in non-generic way at the interconnect code for my use cases: $ git grep "\.context_offs = " arch/arm/mach-omap2/*data.c | wc -l 276 It seems that we could have genpd take care of this in a generic way with the patch I posted. Regards, Tony -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
