On Tue, Jul 30, 2013 at 12:01 AM, Stephen Warren <swar...@wwwdotorg.org> wrote:
> I was thinking more about people writing the device trees that define > these states; they need to explicitly make the choice re: overlapping > states or independent states. We should not plan to obsolete any current > usage of overlapping states since that will mean an incompatible change > to the DT ABI (deprecate yes so that no more usage is added, but the > kernel should still support the old way). This is another reason to not group and encode explicitly the pins that remain unchanged during state transitions. I prefer that either: - when we build up the state containers in the subsystem, we identify overlapping pins and encode them in the state container somehow or: - when transitioning from state A -> state B we identify ovelapping pins or groups of pins and do not touch them by making calls down to the driver ->free() and ->request() callback pair. or: the pinctrl-single.c driver in it's callbacks like ->enable() ->disable(), ->request(), ->free() internally short cuts from its knowledge of such pin shortcuts and no other drivers are affected (nor helped) by this optimization. Yours, Linus Walleij -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
