From:   <miles.chen@mediatek.com>
To:     <matthias.bgg@gmail.com>
CC:     <airlied@linux.ie>, <chunkuang.hu@kernel.org>, <daniel@ffwll.ch>,
        <dri-devel@lists.freedesktop.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>,
        <linux-mediatek@lists.infradead.org>, <miles.chen@mediatek.com>,
        <p.zabel@pengutronix.de>
Subject: Re: [PATCH] drm/mediatek: Fix unused-but-set variable warning
Date:   Thu, 30 Dec 2021 14:56:16 +0800
Message-ID: <20211230065616.32308-1-miles.chen@mediatek.com>
In-Reply-To: <fcaccc97-e920-08eb-ec3f-4c4b11ea8925@gmail.com>
References: <fcaccc97-e920-08eb-ec3f-4c4b11ea8925@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

>You are right, in both cases the bit is set, but the funciton does not do what 
>it is supposed to do.
>Will just clear all bits of the mask.
>
>Without your patch, we will just write the val to the register and don't care 
>what the register value was before that.
>
>We should somehow mention that in the commit message, as it's not only about a 
>not used variable, it actually has an influence on the value we write(-back) to 
>the register.

thanks for the comment. I understand that it's not only about a not used
variable. I talked to our hdmi experts and they think mtk_cec_mask() should
write tmp instead of write val to the register.

I will mention this in the commit message and submit next patch.

Happy new year!

Miles