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

Barry Song
2012-01-31T11:04:57Z

2012/1/31 Wolfram Sang <w.sang@pengutronix.de>:
> On Tue, Jan 31, 2012 at 06:00:00PM +0800, Barry Song wrote:
>> From: Barry Song <Baohua.Song@csr.com>
>>
>> this patch helps to move the common pattern from
>>
>> "
>> res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> if (!res) {
>>       ret = -ENODEV;
>>       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,
>
>   Wolfram
>
> --
> Pengutronix e.K.                           | Wolfram Sang                |
> Industrial Linux Solutions                 | http://www.pengutronix.de/  |

-barry