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From:   Huacai Chen <chenhuacai@kernel.org>
Date:   Mon, 17 Jul 2023 15:05:52 +0800
Message-ID: <CAAhV-H6dn9iRxaGGoD+=7YHiDEmt_Be4_v8d1oY7+dmhrJBUMw@mail.gmail.com>
Subject: Re: [PATCH v4] LoongArch: Fix CONFIG_CMDLINE_EXTEND and
 CONFIG_CMDLINE_BOOTLOADER handling
To:     Dong Zhihong <donmor3000@hotmail.com>
Cc:     kernel@xen0n.name, ardb@kernel.org, tangyouling@loongson.cn,
        zhoubinbin@loongson.cn, yangtiezhu@loongson.cn, tglx@linutronix.de,
        loongarch@lists.linux.dev, linux-kernel@vger.kernel.org
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On Mon, Jul 17, 2023 at 2:51=E2=80=AFPM Dong Zhihong <donmor3000@hotmail.co=
m> wrote:
>
> Make CONFIG_CMDLINE work with CONFIG_CMDLINE_EXTEND and
> CONFIG_CMDLINE_BOOTLOADER. The touched function is bootcmdline_init()`.
> There's already code handling CONFIG_CMDLINE_FORCE, which replaces
> `boot_command_line` with CONFIG_CMDLINE and immediately`goto out`. It'd b=
e
> similar way to handle CONFIG_CMDLINE_EXTEND and CONFIG_CMDLINE_BOOTLOADER=
,
> so some code is added after OF_FLATTREE part to handle them.
>
> Signed-off-by: Dong Zhihong <donmor3000@hotmail.com>
> ---
>
> v4 -> v3: Make CONFIG_CMDLINE appended to the end of command line (Huacai=
);
>         Removed unnecessary #ifdef since CONFIG_CMDLINE is always a strin=
g on
>         LoongArch
>         Reworded comments
>         Reworded the subject of commit message (Huacai)
> v3 -> v2: Reworded the commit message again to make it imperative (Ruoyao=
)
> v2 -> v1: Reworded the commit message so it's more imperative (Markus);
>         Added `goto out` to FDT part (Huacai)
>
>  arch/loongarch/kernel/setup.c | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
>
> diff --git a/arch/loongarch/kernel/setup.c b/arch/loongarch/kernel/setup.=
c
> index 78a00359bde3..a98f33553acf 100644
> --- a/arch/loongarch/kernel/setup.c
> +++ b/arch/loongarch/kernel/setup.c
> @@ -332,9 +332,26 @@ static void __init bootcmdline_init(char **cmdline_p=
)
>                         strlcat(boot_command_line, " ", COMMAND_LINE_SIZE=
);
>
>                 strlcat(boot_command_line, init_command_line, COMMAND_LIN=
E_SIZE);
> +               goto out;
>         }
>  #endif
>
> +       /*
> +        * Append built-in command to the retrieved one if
> +        * CONFIG_CMDLINE_EXTEND is enabled.
> +        */
> +       if (IS_ENABLED(CONFIG_CMDLINE_EXTEND) && CONFIG_CMDLINE[0]) {
Don't need to check CONFIG_CMDLINE[0], this simplifies the conditions.

> +               strlcat(boot_command_line, " ", COMMAND_LINE_SIZE);
> +               strlcat(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_S=
IZE);
> +               goto out;
Remove this line and in the next line using the old method
(IS_ENABLED(CONFIG_CMDLINE_BOOTLOADER) && !boot_command_line[0]) is
better.

Huacai
> +       }
> +
> +       /*
> +        * Use built-in command line if nothing is retrieved from boot lo=
ader.
> +        */
> +       if (!boot_command_line[0])
> +               strscpy(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_S=
IZE);
> +
>  out:
>         *cmdline_p =3D boot_command_line;
>  }
> --
> 2.25.1
>