Hi Tomi, On Tuesday 20 November 2012 22:48:18 Tomi Valkeinen wrote: > I guess there's a reason, but the above looks a bit inconsistent. For > gpio you define the gpio resource inside the step. For power and pwm the > resource is defined before the steps. Why wouldn't "pwm = <&pwm 2 > 5000000>;" work in step2? That's mostly a framework issue. Most frameworks do not export a function that allow to dereference a phandle - they expect resources to be declared right under the device node and accessed by name through foo_get(device, name). So using phandles in power sequences would require to export these additional functions and also opens the door to some inconsistencies - for instance, your PWM phandle could be referenced a second time in the sequence with a different period - how do you know that these are actually referring the same PWM device? > > +When a power sequence is run, its steps is executed one after the other > > until +one step fails or the end of the sequence is reached. > > The document doesn't give any hint of what the driver should do if > running the power sequence fails. Run the "opposite" power sequence? > Will that work for all resources? I'm mainly thinking of a case where > each enable of the resource should be matched by a disable, i.e. you > can't call disable if no enable was called. We discussed that issue already (around v5 I think) and the conclusion was that it should be up to the driver. When we simply enable/disable resources it is easy to revert, but in the future non-boolean properties will likely be introduced, and these cannot easily be reverted. Moreover some drivers might have more complex recovery needs. This deserves more discussion I think, as I'd like to have some "generic" recovery mechanism that covers most of the cases. Alex. -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
