linux-kernel - Re: [PATCH 1/5] clk: sunxi-ng: Remove duplicate ARCH

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Message-ID: <20221203001439.64284671@slackpad.lan>
Date:   Sat, 3 Dec 2022 00:14:57 +0000
From:   Andre Przywara <andre.przywara@....com>
To:     Samuel Holland <samuel@...lland.org>
Cc:     Chen-Yu Tsai <wens@...e.org>,
        Jernej Skrabec <jernej.skrabec@...il.com>,
        Michael Turquette <mturquette@...libre.com>,
        Stephen Boyd <sboyd@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
        Philipp Zabel <p.zabel@...gutronix.de>,
        Rob Herring <robh+dt@...nel.org>, devicetree@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org, linux-clk@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-sunxi@...ts.linux.dev
Subject: Re: [PATCH 1/5] clk: sunxi-ng: Remove duplicate ARCH_SUNXI
 dependencies

On Sat, 26 Nov 2022 13:13:15 -0600
Samuel Holland <samuel@...lland.org> wrote:

Hi,

thanks for addressing this!

> SUNXI_CCU already depends on ARCH_SUNXI, so adding the dependency to
> individual SoC drivers is redundant.
> 
> Signed-off-by: Samuel Holland <samuel@...lland.org>
> ---
> 
>  drivers/clk/sunxi-ng/Kconfig | 43 ++++++++++++++++++------------------
>  1 file changed, 21 insertions(+), 22 deletions(-)
> 
> diff --git a/drivers/clk/sunxi-ng/Kconfig b/drivers/clk/sunxi-ng/Kconfig
> index 461537679c04..64cfa022e320 100644
> --- a/drivers/clk/sunxi-ng/Kconfig
> +++ b/drivers/clk/sunxi-ng/Kconfig
> @@ -14,43 +14,43 @@ config SUNIV_F1C100S_CCU
>  
>  config SUN20I_D1_CCU
>  	tristate "Support for the Allwinner D1 CCU"
> -	default RISCV && ARCH_SUNXI
> -	depends on (RISCV && ARCH_SUNXI) || COMPILE_TEST
> +	default RISCV
> +	depends on RISCV || COMPILE_TEST

I agree on the "depends" part: Indeed the guard symbol already covers
that, so it's redundant.
However I am not so sure about the "default" part: When ARCH_SUNXI is
deselected, but COMPILE_TEST in enabled, we default to every CCU driver
being built-in. I am not sure this is the intention, or at least
expected when doing compile testing?

>  
>  config SUN20I_D1_R_CCU
>  	tristate "Support for the Allwinner D1 PRCM CCU"
> -	default RISCV && ARCH_SUNXI
> -	depends on (RISCV && ARCH_SUNXI) || COMPILE_TEST
> +	default RISCV
> +	depends on RISCV || COMPILE_TEST
>  
>  config SUN50I_A64_CCU
>  	tristate "Support for the Allwinner A64 CCU"
> -	default ARM64 && ARCH_SUNXI
> -	depends on (ARM64 && ARCH_SUNXI) || COMPILE_TEST
> +	default ARM64
> +	depends on ARM64 || COMPILE_TEST

I wonder if this "depends" line was always wrong and should be fixed:
We can compile a 32-bit ARM kernel and run it on an A64. Granted this
requires a special bootloader or a hacked U-Boot (tried that), and
reveals some other issues with the decompressor, but technically there
is no 64-bit dependency in here.
The same goes for all the other ARM64 CCUs: Cortex-A53s can run AArch32
in all exception levels.
So shall we just completely remove the "depends" line for those, and
let SUNXI_CCU do that job? Or use use !RISCV || COMPILE_TEST?

Cheers,
Andre

>  
>  config SUN50I_A100_CCU
>  	tristate "Support for the Allwinner A100 CCU"
> -	default ARM64 && ARCH_SUNXI
> -	depends on (ARM64 && ARCH_SUNXI) || COMPILE_TEST
> +	default ARM64
> +	depends on ARM64 || COMPILE_TEST
>  
>  config SUN50I_A100_R_CCU
>  	tristate "Support for the Allwinner A100 PRCM CCU"
> -	default ARM64 && ARCH_SUNXI
> -	depends on (ARM64 && ARCH_SUNXI) || COMPILE_TEST
> +	default ARM64
> +	depends on ARM64 || COMPILE_TEST
>  
>  config SUN50I_H6_CCU
>  	tristate "Support for the Allwinner H6 CCU"
> -	default ARM64 && ARCH_SUNXI
> -	depends on (ARM64 && ARCH_SUNXI) || COMPILE_TEST
> +	default ARM64
> +	depends on ARM64 || COMPILE_TEST
>  
>  config SUN50I_H616_CCU
>  	tristate "Support for the Allwinner H616 CCU"
> -	default ARM64 && ARCH_SUNXI
> -	depends on (ARM64 && ARCH_SUNXI) || COMPILE_TEST
> +	default ARM64
> +	depends on ARM64 || COMPILE_TEST
>  
>  config SUN50I_H6_R_CCU
>  	tristate "Support for the Allwinner H6 and H616 PRCM CCU"
> -	default ARM64 && ARCH_SUNXI
> -	depends on (ARM64 && ARCH_SUNXI) || COMPILE_TEST
> +	default ARM64
> +	depends on ARM64 || COMPILE_TEST
>  
>  config SUN4I_A10_CCU
>  	tristate "Support for the Allwinner A10/A20 CCU"
> @@ -71,8 +71,7 @@ config SUN6I_A31_CCU
>  
>  config SUN6I_RTC_CCU
>  	tristate "Support for the Allwinner H616/R329 RTC CCU"
> -	default ARCH_SUNXI
> -	depends on ARCH_SUNXI || COMPILE_TEST
> +	default y
>  
>  config SUN8I_A23_CCU
>  	tristate "Support for the Allwinner A23 CCU"
> @@ -91,8 +90,8 @@ config SUN8I_A83T_CCU
>  
>  config SUN8I_H3_CCU
>  	tristate "Support for the Allwinner H3 CCU"
> -	default MACH_SUN8I || (ARM64 && ARCH_SUNXI)
> -	depends on MACH_SUN8I || (ARM64 && ARCH_SUNXI) || COMPILE_TEST
> +	default MACH_SUN8I || ARM64
> +	depends on MACH_SUN8I || ARM64 || COMPILE_TEST
>  
>  config SUN8I_V3S_CCU
>  	tristate "Support for the Allwinner V3s CCU"
> @@ -101,7 +100,7 @@ config SUN8I_V3S_CCU
>  
>  config SUN8I_DE2_CCU
>  	tristate "Support for the Allwinner SoCs DE2 CCU"
> -	default MACH_SUN8I || (ARM64 && ARCH_SUNXI)
> +	default MACH_SUN8I || ARM64
>  
>  config SUN8I_R40_CCU
>  	tristate "Support for the Allwinner R40 CCU"
> @@ -115,6 +114,6 @@ config SUN9I_A80_CCU
>  
>  config SUN8I_R_CCU
>  	tristate "Support for Allwinner SoCs' PRCM CCUs"
> -	default MACH_SUN8I || (ARCH_SUNXI && ARM64)
> +	default MACH_SUN8I || ARM64
>  
>  endif