Re: [RESEND PATCH v27 11/15] leds: lp55xx: Add multicolor framework support to lp55xx

[Jacek Anaszewski <jacek.anaszewski@gmail.com>]

On 6/19/20 12:09 AM, Jacek Anaszewski wrote:
> Dan,
> 
> On 6/18/20 11:44 PM, Dan Murphy wrote:
>> Jacek
>>
>> On 6/18/20 4:21 PM, Jacek Anaszewski wrote:
>>> Dan,
>>>
>>> On 6/18/20 12:33 AM, Dan Murphy wrote:
>>>> Jacek
>>>>
>>>> On 6/17/20 4:41 PM, Jacek Anaszewski wrote:
>>>>> Dan,
>>>>>
>>>>> On 6/17/20 9:22 PM, Dan Murphy wrote:
>>>>>> Pavel/Jacek
>>>>>>
>>>>>> On 6/17/20 11:28 AM, kernel test robot wrote:
>>>>>>> Hi Dan,
>>>>>>>
>>>>>>> I love your patch! Yet something to improve:
>>>>>>>
>>>>>>> [auto build test ERROR on pavel-linux-leds/for-next]
>>>>>>> [cannot apply to j.anaszewski-leds/for-next]
>>>>>>> [if your patch is applied to the wrong git tree, please drop us a 
>>>>>>> note to help
>>>>>>> improve the system. BTW, we also suggest to use '--base' option 
>>>>>>> to specify the
>>>>>>> base tree in git format-patch, please see 
>>>>>>> https://stackoverflow.com/a/37406982]
>>>>>>>
>>>>>>> url: 
>>>>>>> https://github.com/0day-ci/linux/commits/Dan-Murphy/Multicolor-Framework-v27/20200616-042217 
>>>>>>>
>>>>>>> base: 
>>>>>>> git://git.kernel.org/pub/scm/linux/kernel/git/pavel/linux-leds.git for-next 
>>>>>>>
>>>>>>> config: ia64-randconfig-r015-20200617 (attached as .config)
>>>>>>> compiler: ia64-linux-gcc (GCC) 9.3.0
>>>>>>> reproduce (this is a W=1 build):
>>>>>>>          wget 
>>>>>>> https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross 
>>>>>>> -O ~/bin/make.cross
>>>>>>>          chmod +x ~/bin/make.cross
>>>>>>>          # save the attached .config to linux build tree
>>>>>>>          COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 
>>>>>>> make.cross ARCH=ia64
>>>>>>>
>>>>>>> If you fix the issue, kindly add following tag as appropriate
>>>>>>> Reported-by: kernel test robot <lkp@intel.com>
>>>>>>>
>>>>>>> All errors (new ones prefixed by >>, old ones prefixed by <<):
>>>>>>>
>>>>>>> ia64-linux-ld: drivers/leds/leds-lp55xx-common.o: in function 
>>>>>>> `lp55xx_set_mc_brightness':
>>>>>>>>> drivers/leds/leds-lp55xx-common.c:146: undefined reference to 
>>>>>>>>> `led_mc_calc_color_components'
>>>>>>> ia64-linux-ld: drivers/leds/leds-lp55xx-common.o: in function 
>>>>>>> `devm_led_classdev_multicolor_register':
>>>>>>>>> include/linux/led-class-multicolor.h:74: undefined reference to 
>>>>>>>>> `devm_led_classdev_multicolor_register_ext'
>>>>>>> vim +146 drivers/leds/leds-lp55xx-common.c
>>>>>>>
>>>>>>>     138
>>>>>>>     139    static int lp55xx_set_mc_brightness(struct 
>>>>>>> led_classdev *cdev,
>>>>>>>     140                        enum led_brightness brightness)
>>>>>>>     141    {
>>>>>>>     142        struct led_classdev_mc *mc_dev = 
>>>>>>> lcdev_to_mccdev(cdev);
>>>>>>>     143        struct lp55xx_led *led = mcled_cdev_to_led(mc_dev);
>>>>>>>     144        struct lp55xx_device_config *cfg = led->chip->cfg;
>>>>>>>     145
>>>>>>>   > 146 led_mc_calc_color_components(&led->mc_cdev, brightness);
>>>>>>>     147        return cfg->multicolor_brightness_fn(led);
>>>>>>>     148
>>>>>>
>>>>>> Well this was a mess to figure out.
>>>>>>
>>>>>> The only fix I can figure out here is to remove the
>>>>>>
>>>>>>      depends on LEDS_CLASS_MULTI_COLOR || !LEDS_CLASS_MULTI_COLOR
>>>>>>
>>>>>> from each child device and add
>>>>>>
>>>>>>      select LEDS_CLASS_MULTI_COLOR
>>>>>>
>>>>>> to the LP55XX_COMMON
>>>>>>
>>>>>> This way the Multi color framework will inherit the symbol that 
>>>>>> was set by the COMMON flag which is inherited by majority from the 
>>>>>> child flags.
>>>>>
>>>>> Did you try this?
>>>>>
>>>>> --- a/drivers/leds/Kconfig
>>>>> +++ b/drivers/leds/Kconfig
>>>>> @@ -398,6 +398,7 @@ config LEDS_LP50XX
>>>>>  config LEDS_LP55XX_COMMON
>>>>>         tristate "Common Driver for TI/National 
>>>>> LP5521/5523/55231/5562/8501"
>>>>>         depends on LEDS_LP5521 || LEDS_LP5523 || LEDS_LP5562 || 
>>>>> LEDS_LP8501
>>>>> +       depends on LEDS_CLASS_MULTI_COLOR || !LEDS_CLASS_MULTI_COLOR
>>>>>         depends on OF
>>>>>         select FW_LOADER
>>>>>         select FW_LOADER_USER_HELPER
>>>>>
>>>>>
>>>> Yes I did
>>>>
>>>> That gave unmet dependencies.
>>>>
>>>> WARNING: unmet direct dependencies detected for LEDS_LP55XX_COMMON
>>>>    Depends on [m]: NEW_LEDS [=y] && (LEDS_LP5521 [=n] || LEDS_LP5523 
>>>> [=m] || LEDS_LP5562 [=y] || LEDS_LP8501 [=y]) && 
>>>> (LEDS_CLASS_MULTI_COLOR [=m] || !LEDS_CLASS_MULTI_COLOR [=m]) && OF 
>>>> [=y]
>>>>    Selected by [y]:
>>>>    - LEDS_LP5562 [=y] && NEW_LEDS [=y] && LEDS_CLASS [=y] && I2C [=y]
>>>>    - LEDS_LP8501 [=y] && NEW_LEDS [=y] && LEDS_CLASS [=y] && I2C [=y]
>>>>    Selected by [m]:
>>>>    - LEDS_LP5523 [=m] && NEW_LEDS [=y] && LEDS_CLASS [=y] && I2C 
>>>> [=y] && (LEDS_CLASS_MULTI_COLOR [=m] || !LEDS_CLASS_MULTI_COLOR [=m])
>>>>
>>>
>>> When I was testing that yesterday I also had the same warning at some
>>> point of testing different Kconfig setups, but with what I showed above
>>> it ceased to appear. Now every time I am doing "make oldconfig" the
>>> CONFIG_LEDS_LP55XX_COMMON=y entry gets changed to =m with the config
>>> from the test bot.
>>>
>> That is not what I saw in my testing especially after doing a distclean
> 
> Could you please give your exact steps after "make distclean" and
> copying test bot config to the kernel root directory?
> 
> Also, please share the toolchain you're using for tests.

Actually at this stage the toolchain is of lesser relevance.

I've tried once more and indeed the problem shows up.

It is caused by the driver entries doing

"select LEDS_LP55XX_COMMON".

Select sets config to "y" so it conflicts with
"depends on LEDS_CLASS_MULTI_COLOR || !LEDS_CLASS_MULTI_COLOR"
in the "config LEDS_LP55XX_COMMON".

Your proposed fix will block the possibility of building
LED_CLASS_MULTI_COLOR as a module when LP55XX drivers
are enabled so this is also not an option.

Solving this riddle will require some more thinking.
I haven't analyzed it in detail but maybe "imply" statement from
kconfig-language.rst could help somehow here.

-- 
Best regards,
Jacek Anaszewski