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From:   Chunyan Zhang <zhang.lyra@gmail.com>
Date:   Thu, 9 Apr 2020 14:09:16 +0800
Message-ID: <CABOV4+UocLs3jLi7-vTi8muiFqACVdxH7Td8=U1ABveLnmyCuw@mail.gmail.com>
Subject: Re: [PATCH] [RFC] clk: sprd: fix compile-testing
To:     Arnd Bergmann <arnd@arndb.de>
Cc:     catalin.marinas@arm.com, will@kernel.org, mturquette@baylibre.com,
        sboyd@kernel.org, Chunyan Zhang <chunyan.zhang@unisoc.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-arm-kernel@lists.infradead.org,
        LKML <linux-kernel@vger.kernel.org>, linux-clk@vger.kernel.org,
        orson.zhai@unisoc.com, kernel-team@android.com
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Hi Arnd,

Thanks for finding out this and fixing it, but we have a minor concern
for changing ARCH_APRD back to bool.

On Thu, Apr 9, 2020 at 2:57 AM Arnd Bergmann <arnd@arndb.de> wrote:
>
> I got a build failure with CONFIG_ARCH_SPRD=m when the
> main portion of the clock driver failed to get linked into
> the kernel:
>
> ERROR: modpost: "sprd_pll_sc_gate_ops" [drivers/clk/sprd/sc9863a-clk.ko] undefined!
> ERROR: modpost: "sprd_pll_ops" [drivers/clk/sprd/sc9863a-clk.ko] undefined!
> ERROR: modpost: "sprd_div_ops" [drivers/clk/sprd/sc9863a-clk.ko] undefined!
> ERROR: modpost: "sprd_comp_ops" [drivers/clk/sprd/sc9863a-clk.ko] undefined!
> ERROR: modpost: "sprd_mux_ops" [drivers/clk/sprd/sc9863a-clk.ko] undefined!
> ERROR: modpost: "sprd_gate_ops" [drivers/clk/sprd/sc9863a-clk.ko] undefined!
> ERROR: modpost: "sprd_sc_gate_ops" [drivers/clk/sprd/sc9863a-clk.ko] undefined!
> ERROR: modpost: "sprd_clk_probe" [drivers/clk/sprd/sc9863a-clk.ko] undefined!
> ERROR: modpost: "sprd_clk_regmap_init" [drivers/clk/sprd/sc9863a-clk.ko] undefined!
> ERROR: modpost: "sprd_pll_ops" [drivers/clk/sprd/sc9860-clk.ko] undefined!
> ERROR: modpost: "sprd_div_ops" [drivers/clk/sprd/sc9860-clk.ko] undefined!
> ERROR: modpost: "sprd_mux_ops" [drivers/clk/sprd/sc9860-clk.ko] undefined!
>
> This is a combination of two trivial bugs:
>
> - A platform should not be 'tristate', it should be a 'bool' symbol
>   like the other platforms, if only for consistency, and to avoid
>   surprises like this one.

After a discussion, we decided to change ARCH_SPRD to tristate, the
idea was that we hope we can simply switch all sprd drivers' configs
(whose default is ARCH_SPRD) to 'm' by setting ARCH_SPRD=m, or switch
all them to 'y' by setting ARCH_SPRD=y, instead of changing them one
by one. This requirement originally came from that Google GKI project
asks all vendor drivers to be built as modules.

Thanks,
Chunyan

>
> - The clk Makefile does not traverse into the sprd subdirectory
>   if the platform is disabled but the drivers are enabled for
>   compile-testing.
>
> Fixing either of the two would be sufficient to address the link failure,
> but for correctness, both need to be changed.
>
> Fixes: 2b1b799d7630 ("arm64: change ARCH_SPRD Kconfig to tristate")
> Fixes: d41f59fd92f2 ("clk: sprd: Add common infrastructure")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>  arch/arm64/Kconfig.platforms | 2 +-
>  drivers/clk/Makefile         | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm64/Kconfig.platforms b/arch/arm64/Kconfig.platforms
> index 55d70cfe0f9e..3c7e310fd8bf 100644
> --- a/arch/arm64/Kconfig.platforms
> +++ b/arch/arm64/Kconfig.platforms
> @@ -248,7 +248,7 @@ config ARCH_TEGRA
>           This enables support for the NVIDIA Tegra SoC family.
>
>  config ARCH_SPRD
> -       tristate "Spreadtrum SoC platform"
> +       bool "Spreadtrum SoC platform"
>         help
>           Support for Spreadtrum ARM based SoCs
>
> diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
> index f4169cc2fd31..60e811d3f226 100644
> --- a/drivers/clk/Makefile
> +++ b/drivers/clk/Makefile
> @@ -105,7 +105,7 @@ obj-$(CONFIG_CLK_SIFIVE)            += sifive/
>  obj-$(CONFIG_ARCH_SIRF)                        += sirf/
>  obj-$(CONFIG_ARCH_SOCFPGA)             += socfpga/
>  obj-$(CONFIG_PLAT_SPEAR)               += spear/
> -obj-$(CONFIG_ARCH_SPRD)                        += sprd/
> +obj-y                                  += sprd/
>  obj-$(CONFIG_ARCH_STI)                 += st/
>  obj-$(CONFIG_ARCH_STRATIX10)           += socfpga/
>  obj-$(CONFIG_ARCH_SUNXI)               += sunxi/
> --
> 2.26.0
>