On Friday, November 07, 2014 09:50:58 AM Alan Stern wrote: > 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.
Amen. -- 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/
