On Fri, 7 Nov 2014, Krzysztof Kozlowski wrote: > > Well, that is a good reason to introduce a wrapper around power.irq_safe in my > > view. > > > > And define the wrapper so that it always returns false for CONFIG_PM_RUNTIME > > unset. > > > > This way not only you wouldn't need to move the flag from under the #ifdef, > > but also you would make the compiler skip the relevant pieces of code > > entiretly for CONFIG_PM_RUNTIME unset. > > Few days ago I would be happy with your opinion :), but know I think > this is better solution than wrapper. Consider case: > 1. PM_RUNTIME unset. > 2. System suspends. > 3. The pl330 in its suspend callback calls force_runtime_suspend which > leads us to amba/bus. > 4. The amba/bus.c in runtime suspend checks for irq_safe (it is FALSE), > so it disables and unprepares the clock. > 5. The pl330 in probe requested irq_safe so it assumes amba/bus will > only disable the clock. So the pl330 unprepares the clock. Again. To me, this sounds like a good reason to avoid using force_runtime_suspend(). In fact, it sounds like a good reason to avoid relying on the runtime PM mechanism to handle non-runtime-PM things (like a system suspend callback). If CONFIG_PM_RUNTIME isn't enabled then the runtime PM stack simply should not be used. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
