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Date:   Thu, 3 Nov 2022 16:32:38 -0400
From:   =?utf-8?B?TsOtY29sYXMgRi4gUi4gQS4=?= Prado 
        <nfraprado@collabora.com>
To:     "Nancy.Lin" <nancy.lin@mediatek.com>
Cc:     Rob Herring <robh+dt@kernel.org>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        Chun-Kuang Hu <chunkuang.hu@kernel.org>,
        Philipp Zabel <p.zabel@pengutronix.de>, wim@linux-watchdog.org,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>, linux@roeck-us.net,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        "jason-jh . lin" <jason-jh.lin@mediatek.com>,
        Yongqiang Niu <yongqiang.niu@mediatek.com>,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org,
        dri-devel@lists.freedesktop.org, llvm@lists.linux.dev,
        singo.chang@mediatek.com,
        Project_Global_Chrome_Upstream_Group@mediatek.com
Subject: Re: [PATCH v27 05/11] soc: mediatek: refine code to use
 mtk_mmsys_update_bits API
Message-ID: <20221103203238.fryjwpgjtwccnjwu@notapiano>
References: <20221103032512.9144-1-nancy.lin@mediatek.com>
 <20221103032512.9144-6-nancy.lin@mediatek.com>
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On Thu, Nov 03, 2022 at 11:25:06AM +0800, Nancy.Lin wrote:
[..]
> --- a/drivers/soc/mediatek/mtk-mmsys.c
> +++ b/drivers/soc/mediatek/mtk-mmsys.c
[..]
> +static void mtk_mmsys_update_bits(struct mtk_mmsys *mmsys, u32 offset, u32 mask, u32 val)
> +{
> +	u32 tmp;
> +
> +	tmp = readl_relaxed(mmsys->regs + offset);
> +	tmp = (tmp & ~mask) | val;

You should mask the value before writing to prevent bad values from overwriting
bits outside the mask.

	tmp = (tmp & ~mask) | (val & mask);

With that,

Reviewed-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>

Thanks,
Nícolas