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Date:   Wed, 13 Dec 2023 07:32:14 +0100
From:   "Arnd Bergmann" <arnd@arndb.de>
To:     guoren <guoren@kernel.org>, "Arnd Bergmann" <arnd@kernel.org>
Cc:     "Pavel Machek" <pavel@ucw.cz>, "Lee Jones" <lee@kernel.org>,
        "Chen-Yu Tsai" <wens@csie.org>,
        "Jernej Skrabec" <jernej.skrabec@gmail.com>,
        "Samuel Holland" <samuel@sholland.org>,
        "Nathan Chancellor" <nathan@kernel.org>,
        "Palmer Dabbelt" <palmer@rivosinc.com>,
        "Nick Desaulniers" <ndesaulniers@google.com>,
        "Bill Wendling" <morbo@google.com>,
        "Justin Stitt" <justinstitt@google.com>,
        linux-leds@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-sunxi@lists.linux.dev, linux-kernel@vger.kernel.org,
        llvm@lists.linux.dev
Subject: Re: [PATCH] leds: sun50i-a100: avoid division-by-zero warning
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On Wed, Dec 13, 2023, at 02:26, Guo Ren wrote:
> On Wed, Dec 13, 2023 at 5:45=E2=80=AFAM Arnd Bergmann <arnd@kernel.org=
> wrote:
>>  {
>>         const struct sun50i_a100_ledc_timing *timing =3D &priv->timin=
g;
>>         unsigned long mod_freq =3D clk_get_rate(priv->mod_clk);
>> -       u32 cycle_ns =3D NSEC_PER_SEC / mod_freq;
>> +       u32 cycle_ns;
>>         u32 control;
>>
>> +       if (!mod_freq)
>> +               return;
>> +
> Shall we need err_disable_bus_clk?
>
> + static int sun50i_a100_ledc_set_timing(struct sun50i_a100_ledc *priv)
> - static void sun50i_a100_ledc_set_timing(struct sun50i_a100_ledc *pri=
v)

I'm not worried about it too much, as there is already an error check
on priv->mod_clk being unavailable during initialization. The case that
the warning is about is just for build-testing on architectures that
don't even use COMMON_CLK.

     Arnd