Re: [PATCH v4 2/3] hwrng: add Rockchip SoC hwrng driver

[Dragan Simic <dsimic@manjaro.org>]

Hello Uwe,

On 2024-06-23 11:46, Uwe Kleine-König wrote:
> On 6/23/24 09:00, Krzysztof Kozlowski wrote:
>> On 23/06/2024 05:33, Daniel Golle wrote:
>>> +
>>> +	pm_runtime_set_autosuspend_delay(dev, RK_RNG_AUTOSUSPEND_DELAY);
>>> +	pm_runtime_use_autosuspend(dev);
>>> +	devm_pm_runtime_enable(dev);
>>> +
>>> +	ret = devm_hwrng_register(dev, &rk_rng->rng);
>>> +	if (ret)
>>> +		return dev_err_probe(&pdev->dev, ret, "Failed to register Rockchip 
>>> hwrng\n");
>>> +
>>> +	dev_dbg(&pdev->dev, "Registered Rockchip hwrng\n");
>> 
>> Drop, it is not useful at all. Srsly, we had already long enough talk,
>> [...]
> 
> And in this long talk using dev_dbg() was one of the suggestions for a
> compromise. For me this is ok.
> 
>> There is no single benefit of such debug statement. sysfs already
>> provides you this information. Simple entry/exit  is provided by
>> tracing. You duplicate existing interfaces without any benefit, 
>> because
>> this prints nothing more.
> 
> There might be a (small) value if you want to know when during boot
> the device becomes available. So having a dev_dbg() that can be
> enabled dynamically (assuming DYNAMIC_DEBUG=y) and isn't in the way
> otherwise might be justified. IMHO a dev_dbg is lightweight enough
> that *I* won't continue the discussion.

For anyone interested, below is an example that shows the usability
of knowing when a device becomes available:

https://gitlab.manjaro.org/manjaro-arm/packages/core/linux/-/issues/21