On Mon, Jan 31, 2011 at 03:16:15PM -0800, Kevin Hilman wrote: > Hi Rafael, > > "Rafael J. Wysocki" <rjw@xxxxxxx> writes: > > > Hi, > > > > This is something we discussed during the last Linux Plumbers Conference. > > > > The problem appears to be that the same device may be used in different > > systems in different configurations such that actions necessary for the > > device's power management can vary from one system to another. In those > > cases the drivers' power management callbacks are generally not sufficient, > > because they can't take the configuration of the whole system into account. > > > > I think this issue may be addressed by adding objects that will represent > > power domains and will provide power management callbacks to be executed > > in addition to the device driver's PM callbacks, which is done by the patch > > below. > > > > Please have a look at it and tell me what you think. > > Very nice. I like the approach and the fact that it allows grouping of > only devices we care about customizing, instead of every device on the > platform_bus (I know Grant will like that part too. :) :-D > I experimented with something similar before I took the easy way out > with platform_bus_set_pm_ops() :/ > > This approach might also solve the problem(s) we've been discussing > around the conflicts between runtime PM callbacks and system PM > callbacks (that RTC vs. i2c issue.) With this approach, I shouldn't > have to to add the callbacks like I did for the i2c driver, but rather > handle them in common code. I'll experiment with this... > > The primary question for me is whether this should rather be at the > 'struct device' level instead of at the platform_device level. While > we're currently only using this customization on platform_devices, I > don't think we should limit it to that. Part of these discussions at > LPC was also about whether or not to move to using custom SoC-specific > devices and busses. If/when we go that route, we'd want these power > domains part of struct device, not platform_device. Definitely should be at the struct device level IMNSHO. _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
