[PATCH V2 1/2] leds: gpio: Add kernel log if devm_fwnode_gpiod_get fails

[Stefan Wahren]

Am 22.11.23 um 11:52 schrieb Bartosz Golaszewski:
> On Mon, Nov 20, 2023 at 1:36 PM Andy Shevchenko
> <andriy.shevchenko at linux.intel.com> wrote:
>> On Mon, Nov 20, 2023 at 01:02:55PM +0100, Stefan Wahren wrote:
>>> Am 20.11.23 um 12:47 schrieb Andy Shevchenko:
>>>> On Sat, Nov 18, 2023 at 01:42:51PM +0100, Stefan Wahren wrote:
>>>>> In case leds-gpio fails to get the GPIO from the DT (e.g. the GPIO is
>>>>> already requested) the driver doesn't provide any helpful error log:
>>>>>
>>>>>       leds-gpio: probe of leds failed with error -16
>>>>>
>>>>> So add a new error log in case devm_fwnode_gpiod_get() fails.
>> ...
>>
>>>>>                    led.gpiod = devm_fwnode_gpiod_get(dev, child, NULL, GPIOD_ASIS,
>>>>>                                                      NULL);
>>>>>                    if (IS_ERR(led.gpiod)) {
>>>>> +                 dev_err_probe(dev, PTR_ERR(led.gpiod), "Failed to get gpio '%pfw'\n",
>>>>> +                               child);
>>>>>                            fwnode_handle_put(child);
>>>>>                            return ERR_CAST(led.gpiod);
>>>>>                    }
>>>> Thinking more about it. GPIO library already issues bunch of messages.
>>>>
>>>>      "using DT ... for ... GPIO lookup"
>>>>      "using lookup tables for GPIO lookup"
>>>>      "No GPIO consumer ... found"
>>> are these errors or debug messages?
>> Indeed they are on debug level.
>>
>>> I cannot remember that i saw any of them on info level in my case of an
>>> already allocated pin (see patch 2).
>>>
>>> I'm open to place the log within gpiolib, if this a better place.
>> I'm not sure, let's hear GPIO maintainers for that.
>>
> Hard to tell which method is preferred among all the subsystems.
> Personally I'm more inclined towards letting drivers decide whether to
> emit an error message and only emit our own when an error cannot be
> propagated down the stack.
>
> Linus: Any thoughts?
gentle ping ...
>
> Bart
>
>>>> Isn't it enough?
>> --
>> With Best Regards,
>> Andy Shevchenko
>>
>>
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