Message-ID: <fcaccc97-e920-08eb-ec3f-4c4b11ea8925@gmail.com>
Date:   Tue, 28 Dec 2021 15:53:55 +0100
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101
 Thunderbird/91.2.0
Content-Language: en-US
To:     Miles Chen <miles.chen@mediatek.com>,
        Chun-Kuang Hu <chunkuang.hu@kernel.org>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>
Cc:     dri-devel@lists.freedesktop.org,
        linux-mediatek@lists.infradead.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
References: <20211228092527.29894-1-miles.chen@mediatek.com>
From:   Matthias Brugger <matthias.bgg@gmail.com>
Subject: Re: [PATCH] drm/mediatek: Fix unused-but-set variable warning
In-Reply-To: <20211228092527.29894-1-miles.chen@mediatek.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk


On 28/12/2021 10:25, Miles Chen wrote:
> Fix unused-but-set variable warning:
> drivers/gpu/drm/mediatek/mtk_cec.c:85:6: warning: variable 'tmp' set but not used [-Wunused-but-set-variable]
> 

Actually we ignore the value passed to mtk_cec_mask. In case of
mtk_cec_mask(cec, CEC_CKGEN, 0 | CEC_32K_PDN, PDN | CEC_32K_PDN);


We are not setting CEC_32K_PDN. I wonder which side effect will it have to set 
that bit.

Anyway, if it's the right thing to do, we should add:

Fixes: 8f83f26891e1 ("drm/mediatek: Add HDMI support")


Regards,
Matthias

> Signed-off-by: Miles Chen <miles.chen@mediatek.com>
> ---
>   drivers/gpu/drm/mediatek/mtk_cec.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_cec.c b/drivers/gpu/drm/mediatek/mtk_cec.c
> index e9cef5c0c8f7..cdfa648910b2 100644
> --- a/drivers/gpu/drm/mediatek/mtk_cec.c
> +++ b/drivers/gpu/drm/mediatek/mtk_cec.c
> @@ -85,7 +85,7 @@ static void mtk_cec_mask(struct mtk_cec *cec, unsigned int offset,
>   	u32 tmp = readl(cec->regs + offset) & ~mask;
>   
>   	tmp |= val & mask;
> -	writel(val, cec->regs + offset);
> +	writel(tmp, cec->regs + offset);
>   }
>   
>   void mtk_cec_set_hpd_event(struct device *dev,
>