Hello Joe,
Thanks a lot for your feedback.
On 03/14/2016 04:11 PM, Joe Perches wrote:
> On Mon, 2016-03-14 at 16:05 -0300, Javier Martinez Canillas wrote:
>> The clock and source clock looked up by the driver may not be available
>> just because the clock controller driver was not probed yet so printing
>> an error in this case is not correct and only adds confusion to users.
>>
>> However, knowing that a driver's probe was deferred may be useful so it
>> can be printed as debug information.
> []
>> diff --git a/drivers/rtc/rtc-s3c.c b/drivers/rtc/rtc-s3c.c
> []
>> @@ -501,18 +501,27 @@ static int s3c_rtc_probe(struct platform_device *pdev)
>>
>> info->rtc_clk = devm_clk_get(&pdev->dev, "rtc");
>> if (IS_ERR(info->rtc_clk)) {
>> - dev_err(&pdev->dev, "failed to find rtc clock\n");
>> - return PTR_ERR(info->rtc_clk);
>> + ret = PTR_ERR(info->rtc_clk);
>> + if (ret != -EPROBE_DEFER)
>> + dev_err(&pdev->dev, "failed to find rtc clock\n");
>> + else
>> + dev_dbg(&pdev->dev, "probe deferred due rtc clock\n");
>> + return ret;
>> }
>> clk_prepare_enable(info->rtc_clk);
>>
>> 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 rtc source
>> clock\n");
>> clk_disable_unprepare(info->rtc_clk);
>> - return PTR_ERR(info->rtc_src_clk);
>> + return ret;
>> }
>> clk_prepare_enable(info->rtc_src_clk);
>> }
>
> Maybe the debug logging messages could be object->action like:
>
> rtc clock probe deferred
> rtc source clock probe deferred
>
I found your suggested messages harder to read and more confusing. The
action that happens is a probe function deferral and that is caused by
a missing resource needed by the driver (clocks in this case).
But your messages seems to imply that the probe deferred action happens
to a clock, it sounds like "rtc clock disabled" and that's not correct.
Best regards,
--
Javier Martinez Canillas
Open Source Group
Samsung Research America
