[alsa-devel] [PATCH v4 7/9] davinci: MMC/SD support for Omapl138-Hawkboar

[Jon Povey]

Victor Rodriguez wrote:
> On Mon, Oct 18, 2010 at 8:16 PM, Jon Povey
> <Jon.Povey at racelogic.co.uk> wrote:
>> davinci-linux-open-source-bounces at linux.davincidsp.com wrote:
>>> I think that you mean that I should not call gpio_direction_input if
>>> gpio_request failed am I right ?
>>
>> Yes, if gpio_request() fails that means you have not claimed that
>> gpio, something else is using it already or it's not available due
>> to other misconfiguration.
>>
>> So you shouldn't be trying to set its direction or anything like
>> that.

> Yes you are right and as I understand gpio_request will give a 0 if it
> success and because of that the warning never will appear, if there is
> a problem there will be a -1 and the warning will be printed. I could
> fix this with a return that breaks the code like this
>
>        ret = gpio_request(DA850_HAWK_MMCSD_CD_PIN, "MMC CD\n");
>                if (ret) { pr_warning("%s: can not open GPIO %d\n",
>                        __func__, DA850_HAWK_MMCSD_CD_PIN);
>        return; }
>        gpio_direction_input(DA850_HAWK_MMCSD_CD_PIN);
>
> Is this ok ?

I haven't seen the rest of your code to tell if that is OK, but
not calling any other gpio_* functions if the request fails is
the right idea.

You may need to do more cleanup to gracefuly handle the failure,
like returning an error value at least.

--
Jon Povey
jon.povey at racelogic.co.uk

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