On 07/23/2013 02:07 PM, Gerhard Sittig wrote: [...] >>> + return freq_calc; >>> + >>> +err_invalid: >>> + dev_err(&ofdev->dev, "invalid clock source specification\n"); >>> + return 0; >> >> return 0 in case of error? Please add a comment what this 0 means here. > > The .get_clock() callback is supposed to return the resulting > rate after the clock source was determined and the clock subtree > was setup. It wasn't (explicitly) documented before (in the > non-common-clock case), so I did not bother to comment it in the > parallel common-clock case. Yes, but returning 0 in case of error should be documented, as it's very uncommon. > But it's true that returning zero in the error case may be > unexpected, and I will add a comment in v4 (in all the > .get_clock() implementations). I think a one liner stating that the return value is the clock rate and "0" indicates is an invalid clock rate, this meaning an error here, is enough. Marc -- Pengutronix e.K. | Marc Kleine-Budde | Industrial Linux Solutions | Phone: +49-231-2826-924 | Vertretung West/Dortmund | Fax: +49-5121-206917-5555 | Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de |