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References: <20230929053915.1530607-1-claudiu.beznea@bp.renesas.com> <20230929053915.1530607-4-claudiu.beznea@bp.renesas.com>
In-Reply-To: <20230929053915.1530607-4-claudiu.beznea@bp.renesas.com>
From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Tue, 3 Oct 2023 17:18:06 +0200
Message-ID: <CAMuHMdWQJBYhhEYDBYqek_h_0a7b1iSDK6cjBTiD-xqNrWrhNQ@mail.gmail.com>
Subject: Re: [PATCH v2 03/28] clk: renesas: rzg2l: lock around writes to mux register
To:     Claudiu <claudiu.beznea@tuxon.dev>
Cc:     mturquette@baylibre.com, sboyd@kernel.org, robh+dt@kernel.org,
        krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org,
        linus.walleij@linaro.org, gregkh@linuxfoundation.org,
        jirislaby@kernel.org, magnus.damm@gmail.com,
        catalin.marinas@arm.com, will@kernel.org,
        quic_bjorande@quicinc.com, konrad.dybcio@linaro.org, arnd@arndb.de,
        neil.armstrong@linaro.org, prabhakar.mahadev-lad.rj@bp.renesas.com,
        biju.das.jz@bp.renesas.com, linux-renesas-soc@vger.kernel.org,
        linux-clk@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org,
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On Fri, Sep 29, 2023 at 7:39 AM Claudiu <claudiu.beznea@tuxon.dev> wrote:
> From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
>
> SD MUX output (SD0) is further divided by 4 in G2{L, UL}. The divided
> clock is SD0_DIV4. SD0_DIV4 is registered with CLK_SET_RATE_PARENT which
> means a rate request for it is propagated to the MUX and could reach
> rzg2l_cpg_sd_clk_mux_set_parent() concurrently with the users of SD0.
> Add proper locking to avoid concurrent access on SD MUX set rate
> registers.
>
> Fixes: eaff33646f4cb ("clk: renesas: rzg2l: Add SDHI clk mux support")
> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
> ---
>
> Changes in v2:
> - adapted delay_us to 10us
> - adapted CPG_SDHI_CLK_SWITCH_STATUS_TIMEOUT_US to 200us; tested
>   with this adjustements on RZ/G3S and RZ/G2L SoCs

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
i.e. will queue in renesas-clk-for-v6.7.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds