Messages in this thread | | | From | Barry Song <> | Date | Tue, 31 Jan 2012 20:09:19 +0800 | Subject | Re: [PATCH 1/3] platform: add common resource requesting and mapping helper |
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hi Wolfram,
2012/1/31 Wolfram Sang <w.sang@pengutronix.de>: > Barry, > >> > You don't need to do the error checking for 'res'. You can simply do >> > >> > res = platform_get_resource(pdev, IORESOURCE_MEM, 0); >> > base = devm_request_and_ioremap(&dev->dev, res); >> >> i do know devm_request_and_ioremap() does res checking. but that is >> implicit, confused and not a smart way actually. > > I agree about the implicit thing (keep in mind the function is new). But > calling a function "not smart" because it checks its arguments? I do > like the NULL check of kfree() for example.
i didn't mean it is not smart for devm_request_and_ioremap() to check its param. that is definitely ok. i mean it is not smart for people to depend on another function to do implicit check on what they should check by themselves. > >> actually, no people by now really use the implicit checking. that >> shows people don't really think that is a good programming way. > > I'd think most people just copy&paste and don't have an opinion either > way, so the quantity doesn't show much. > >> > devm_request_and_ioremap() will check res. Given that, I don't think >> > we can save a lot with another wrapper. >> >> i think we can save some. >> The story begins from Grant's feedback in: >> http://www.spinics.net/lists/arm-kernel/msg157644.html > > I am not sure using 'platform_devm_request_and_ioremap' and later using > plain 'devm_*' functions (without platform_-prefix) is less confusing. > The alternative would be to check which helper functions also use > 'struct resource' and if they do checks on that. If all do that, you > would have the simple rule, that you only need to check yourself if you > access it yourself.
it is just a helper, just like clk_disable_unprepare() which do clk_disable() + clk_unprepare().
> > Regards, > > Wolfram > > -- > Pengutronix e.K. | Wolfram Sang | > Industrial Linux Solutions | http://www.pengutronix.de/ | -barry -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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