[PATCH v3 1/3] Convert CONFIG_SYS_L2_PL310 to Kconfig

[Marek Vasut]

On 8/9/22 13:21, Pali Rohár wrote:

(reducing the CC list)

> On Tuesday 09 August 2022 13:16:41 Marek Vasut wrote:
>> On 8/9/22 12:58, Pali Rohár wrote:
>>> On Tuesday 09 August 2022 12:07:00 Philip Oberfichtner wrote:
>>>> This converts CONFIG_SYS_L2_PL310 to Kconfig.
>>> ...
>>>> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
>>>> index 949ebb46ba..dde06bdd96 100644
>>>> --- a/arch/arm/Kconfig
>>>> +++ b/arch/arm/Kconfig
>>>> @@ -488,6 +488,10 @@ config TPL_SYS_THUMB_BUILD
>>>>    	   density. For ARM architectures that support Thumb2 this flag will
>>>>    	   result in Thumb2 code generated by GCC.
>>>> +config SYS_L2_PL310
>>>> +	bool "ARM PL310 L2 cache controller"
>>>> +	help
>>>> +	  Enable support for ARM PL310 L2 cache controller in U-Boot
>>>>    config SYS_L2CACHE_OFF
>>>>    	bool "L2cache off"
>>>> diff --git a/arch/arm/mach-mvebu/include/mach/config.h b/arch/arm/mach-mvebu/include/mach/config.h
>>>> index 4add0d9e10..0bba0a4cf9 100644
>>>> --- a/arch/arm/mach-mvebu/include/mach/config.h
>>>> +++ b/arch/arm/mach-mvebu/include/mach/config.h
>>>> @@ -25,8 +25,6 @@
>>>>    #define MV88F78X60 /* for the DDR training bin_hdr code */
>>>>    #endif
>>>> -#define CONFIG_SYS_L2_PL310
>>>> -
>>>>    #define MV_UART_CONSOLE_BASE		MVEBU_UART0_BASE
>>>>    /* Needed for SPI NOR booting in SPL */
>>>
>>> This option is required for mvebu SoC and is not user (de)-selectable.
>>> So please do not define it in each individual mvebu board. It would make
>>> it harder to introduce a new mvebu board into U-Boot. Instead enable it
>>> for mvebu SoCs like it was before this change. It can be done e.g. by
>>> "select" Kconfig keyword in mvebu Kconfig file.
>>
>> Should it rather be 'default y if MVEBU' in that new PL310 Kconfig option ?
> 
> No, because this is just default value of this option and still allows
> end-user to de-select this option.
> 
> "select" is IIRC the only way how to force Kconfig to always enable some
> symbol without any option for end-user to disable it.
> 
> At least I do not know a way how CONFIG_SYS_L2_PL310 symbol could decide
> that it is required for CONFIG_MVEBU. Just symbol CONFIG_MVEBU can
> decide that it requires CONFIG_SYS_L2_PL310 symbol (and not in opposite
> direction).

So why should the user be unable to deselect L2CC support on MVEBU ?
I can very well disable L2CC support on MX6 and the platform works 
without it just fine. Maybe the MVEBU needs to be fixed to support the 
same instead ?