Re: [PATCH 1/2] memory: tegra: Add missing dependencies

[Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>]

On 09/06/2021 18:57, Dmitry Osipenko wrote:
> 09.06.2021 16:19, Krzysztof Kozlowski пишет:
>> On 09/06/2021 13:58, Dmitry Osipenko wrote:
>>> 09.06.2021 14:28, Thierry Reding пишет:
>>>> From: Thierry Reding <treding@nvidia.com>
>>>>
>>>> When enabling the COMPILE_TEST Kconfig option, the Tegra memory
>>>> controller can be built without ARCH_TEGRA being selected. However, the
>>>> driver implicitly depends on some symbols pulled in via ARCH_TEGRA,
>>>> which causes the build to break.
>>>>
>>>> Add explicit dependencies for OF_EARLY_FLATTREE and OF_RESERVED_MEM to
>>>> the Tegra MC Kconfig option to make sure they are selected even if
>>>> ARCH_TEGRA is not.
>>>>
>>>> Reported-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
>>>> Signed-off-by: Thierry Reding <treding@nvidia.com>
>>>> ---
>>>>  drivers/memory/tegra/Kconfig | 2 ++
>>>>  1 file changed, 2 insertions(+)
>>>>
>>>> diff --git a/drivers/memory/tegra/Kconfig b/drivers/memory/tegra/Kconfig
>>>> index f9bae36c03a3..ecfb071fc4f4 100644
>>>> --- a/drivers/memory/tegra/Kconfig
>>>> +++ b/drivers/memory/tegra/Kconfig
>>>> @@ -48,6 +48,8 @@ config TEGRA124_EMC
>>>>  config TEGRA210_EMC_TABLE
>>>>  	bool
>>>>  	depends on ARCH_TEGRA_210_SOC || COMPILE_TEST
>>>> +	select OF_EARLY_FLATTREE
>>>> +	select OF_RESERVED_MEM
>>>>  
>>>>  config TEGRA210_EMC
>>>>  	tristate "NVIDIA Tegra210 External Memory Controller driver"
>>>>
>>>
>>> Will this work if CONFIG_OF is disabled?
>>
>> Yeah, good question. That's why I propose "depends on". No issues with
>> unmet or circular dependencies.
> 
> What about to add stub for RESERVEDMEM_OF_DECLARE() + CONFIG_OF_RESERVED_MEM=n?
> 
> diff --git a/include/linux/of.h b/include/linux/of.h
> index d8db8d3592fd..9c2e71e202d1 100644
> --- a/include/linux/of.h
> +++ b/include/linux/of.h
> @@ -1329,6 +1329,12 @@ static inline int of_get_available_child_count(const struct device_node *np)
>  	return num;
>  }
>  
> +#define _OF_DECLARE_STUB(table, name, compat, fn, fn_type)		\
> +	static const struct of_device_id __of_table_##name		\
> +		__attribute__((unused))					\
> +		 = { .compatible = compat,				\
> +		     .data = (fn == (fn_type)NULL) ? fn : fn }
> +
>  #if defined(CONFIG_OF) && !defined(MODULE)
>  #define _OF_DECLARE(table, name, compat, fn, fn_type)			\
>  	static const struct of_device_id __of_table_##name		\
> @@ -1338,10 +1344,7 @@ static inline int of_get_available_child_count(const struct device_node *np)
>  		     .data = (fn == (fn_type)NULL) ? fn : fn  }
>  #else
>  #define _OF_DECLARE(table, name, compat, fn, fn_type)			\
> -	static const struct of_device_id __of_table_##name		\
> -		__attribute__((unused))					\
> -		 = { .compatible = compat,				\
> -		     .data = (fn == (fn_type)NULL) ? fn : fn }
> +	_OF_DECLARE_STUB(table, name, compat, fn, fn_type)
>  #endif
>  
>  typedef int (*of_init_fn_2)(struct device_node *, struct device_node *);
> diff --git a/include/linux/of_reserved_mem.h b/include/linux/of_reserved_mem.h
> index 76e4a0fffba4..4de2a24cadc9 100644
> --- a/include/linux/of_reserved_mem.h
> +++ b/include/linux/of_reserved_mem.h
> @@ -27,11 +27,11 @@ struct reserved_mem_ops {
>  
>  typedef int (*reservedmem_of_init_fn)(struct reserved_mem *rmem);
>  
> +#ifdef CONFIG_OF_RESERVED_MEM
> +
>  #define RESERVEDMEM_OF_DECLARE(name, compat, init)			\
>  	_OF_DECLARE(reservedmem, name, compat, init, reservedmem_of_init_fn)
>  
> -#ifdef CONFIG_OF_RESERVED_MEM
> -
>  int of_reserved_mem_device_init_by_idx(struct device *dev,
>  				       struct device_node *np, int idx);
>  int of_reserved_mem_device_init_by_name(struct device *dev,
> @@ -41,6 +41,10 @@ void of_reserved_mem_device_release(struct device *dev);
>  
>  struct reserved_mem *of_reserved_mem_lookup(struct device_node *np);
>  #else
> +
> +#define RESERVEDMEM_OF_DECLARE(name, compat, init)			\
> +	_OF_DECLARE_STUB(reservedmem, name, compat, init, reservedmem_of_init_fn)
> +
>  static inline int of_reserved_mem_device_init_by_idx(struct device *dev,
>  					struct device_node *np, int idx)
>  {

The stubs might be good idea anyway, but the driver explicitly needs for
runtime working reservedmem, so it should select it.

Best regards,
Krzysztof