On Fri, 2018-05-25 at 15:52 +0100, Mark Brown wrote: > On Fri, May 25, 2018 at 01:42:53PM +0200, Marco Felsch wrote: > > > Also the formula for the delay time (t = C × 25,000/3.5) depends only on > > the capacity size. > > Why not just have the user specify the capacitance of the capacitor on > the rail which they can directly read from the schematic rather than > forcing them to do the calcualtion? That seems a bit clearer and more > user friendly (plus if someone decides the spec was wrong it's easier to > roll out fixes). The exact capacitance may not be known or vary above the nominal value because of cheap components, and the formula from the datasheet is just a guideline. I'd expect the usual method to set this delay to be semi-empirical: "start from the value calculated from datasheet and schematics and then increase until no more audio artifacts on a representative sample of boards". I think it is be better to specify a delay that works than a bogus capacitance value that happens to correspond to a delay that works. regards Philipp -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
