Re: [PATCH 1/3] platform: add common resource requesting and mapping helper

From: Barry Song
Date: Tue Jan 31 2012 - 06:04:54 EST


2012/1/31 Wolfram Sang <w.sang@xxxxxxxxxxxxxx>:
> On Tue, Jan 31, 2012 at 06:00:00PM +0800, Barry Song wrote:
>> From: Barry Song <Baohua.Song@xxxxxxx>
>>
>> this patch helps to move the common pattern from
>>
>> "
>> res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> if (!res) {
>> Â Â Â ret = -ENODEV;
>> Â Â Â goto err;
>> }
>
> 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.
actually, no people by now really use the implicit checking. that
shows people don't really think that is a good programming way.

>
> 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

>
> Thanks,
>
> Â Wolfram
>
> --
> Pengutronix e.K.              | Wolfram Sang        Â|
> Industrial Linux Solutions         | http://www.pengutronix.de/ Â|

-barry
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