Re: [PATCH v3] rtc: s3c: Don't print an error on probe deferral

From: Javier Martinez Canillas
Date: Mon Mar 14 2016 - 22:59:12 EST


Hello Krzysztof,

On 03/14/2016 11:26 PM, Krzysztof Kozlowski wrote:
> On 15.03.2016 10:59, Javier Martinez Canillas wrote:
>>>>
>>>> if (info->data->needs_src_clk) {
>>>> info->rtc_src_clk = devm_clk_get(&pdev->dev, "rtc_src");
>>>> if (IS_ERR(info->rtc_src_clk)) {
>>>> - dev_err(&pdev->dev,
>>>> - "failed to find rtc source clock\n");
>>>> + ret = PTR_ERR(info->rtc_src_clk);
>>>> + if (ret != -EPROBE_DEFER)
>>>> + dev_err(&pdev->dev,
>>>> + "failed to find rtc source clock\n");
>>>> + else
>>>> + dev_dbg(&pdev->dev,
>>>> + "probe deferred due to missing rtc src clk\n");
>>>> clk_disable_unprepare(info->rtc_clk);
>>>> - return PTR_ERR(info->rtc_src_clk);
>>>> + return ret;
>>>> }
>>>> clk_prepare_enable(info->rtc_src_clk);
>>>> }
>>>>
>>>
>>> The error path starts looking complicated. This has now 4 indentation
>>> levels...
>>>
>>
>> Yeah, I don't think we can get rid of the 4 indentation levels since
>> the function already has 3 and a check for the errno code is needed.
>
> Probably handling of the clocks in the driver could be simplified a
> little bit (the if(needs_src_clk) appears in few places)... but this is
> out of scope for this patch.
>

Agreed, I meant without introducing an unrelated change.

>>
>>> I agree for removal of error in case of probe deferral because it might
>>> be misleading but I don't see much benefit of a debug message.
>>>
>>
>> But yes, we can at least get rid of the else statement. I don't have a
>> strong opinion about the debug information, I left it to avoid someone
>> to tell me that I was removing a useful log.
>
> Although dev_dbg doesn't harm... but isn't driver core printing debug
> message already?
>

I don't think it does or at least I didn't find it when looking
at the devm_clk_get() call chain.

> BR,
> Krzysztof
>

Best regards,
--
Javier Martinez Canillas
Open Source Group
Samsung Research America