linux-kernel - Re: [PATCH 4/4] media: i2c: ds90ub953: use guard() to simplify code

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Message-ID: <aMH8KRdUZ0OQIyY8@lizhi-Precision-Tower-5810>
Date: Wed, 10 Sep 2025 18:31:05 -0400
From: Frank Li <Frank.li@....com>
To: Guoniu Zhou <guoniu.zhou@....com>
Cc: Tomi Valkeinen <tomi.valkeinen@...asonboard.com>,
	Mauro Carvalho Chehab <mchehab@...nel.org>,
	Rob Herring <robh@...nel.org>,
	Krzysztof Kozlowski <krzk+dt@...nel.org>,
	Conor Dooley <conor+dt@...nel.org>, linux-media@...r.kernel.org,
	devicetree@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 4/4] media: i2c: ds90ub953: use guard() to simplify code

On Wed, Sep 10, 2025 at 05:44:41PM +0800, Guoniu Zhou wrote:
> Use guard() to simplify mutex locking. No functional change.
>
> Signed-off-by: Guoniu Zhou <guoniu.zhou@....com>
> ---

Reviewed-by: Frank Li <Frank.Li@....com>

>  drivers/media/i2c/ds90ub953.c | 34 +++++++++++++---------------------
>  1 file changed, 13 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/media/i2c/ds90ub953.c b/drivers/media/i2c/ds90ub953.c
> index 6f09322553640384b1f43af0dbdf4f54b4ba004a..d7799531773ee32bf9f95eef30618cce9d479dd0 100644
> --- a/drivers/media/i2c/ds90ub953.c
> +++ b/drivers/media/i2c/ds90ub953.c
> @@ -112,20 +112,18 @@ static int ub953_read(struct ub953_data *priv, u8 reg, u8 *val, int *err)
>  	if (err && *err)
>  		return *err;
>
> -	mutex_lock(&priv->reg_lock);
> +	guard(mutex)(&priv->reg_lock);
>
>  	ret = regmap_read(priv->regmap, reg, &v);
>  	if (ret) {
>  		dev_err(&priv->client->dev, "Cannot read register 0x%02x: %d\n",
>  			reg, ret);
> -		goto out_unlock;
> +		goto err;
>  	}
>
>  	*val = v;
>
> -out_unlock:
> -	mutex_unlock(&priv->reg_lock);
> -
> +err:
>  	if (ret && err)
>  		*err = ret;
>
> @@ -139,15 +137,13 @@ static int ub953_write(struct ub953_data *priv, u8 reg, u8 val, int *err)
>  	if (err && *err)
>  		return *err;
>
> -	mutex_lock(&priv->reg_lock);
> +	guard(mutex)(&priv->reg_lock);
>
>  	ret = regmap_write(priv->regmap, reg, val);
>  	if (ret)
>  		dev_err(&priv->client->dev,
>  			"Cannot write register 0x%02x: %d\n", reg, ret);
>
> -	mutex_unlock(&priv->reg_lock);
> -
>  	if (ret && err)
>  		*err = ret;
>
> @@ -184,18 +180,18 @@ static int ub953_read_ind(struct ub953_data *priv, u8 block, u8 reg, u8 *val,
>  	if (err && *err)
>  		return *err;
>
> -	mutex_lock(&priv->reg_lock);
> +	guard(mutex)(&priv->reg_lock);
>
>  	ret = ub953_select_ind_reg_block(priv, block);
>  	if (ret)
> -		goto out_unlock;
> +		goto err;
>
>  	ret = regmap_write(priv->regmap, UB953_REG_IND_ACC_ADDR, reg);
>  	if (ret) {
>  		dev_err(&priv->client->dev,
>  			"Write to IND_ACC_ADDR failed when reading %u:0x%02x: %d\n",
>  			block, reg, ret);
> -		goto out_unlock;
> +		goto err;
>  	}
>
>  	ret = regmap_read(priv->regmap, UB953_REG_IND_ACC_DATA, &v);
> @@ -203,14 +199,12 @@ static int ub953_read_ind(struct ub953_data *priv, u8 block, u8 reg, u8 *val,
>  		dev_err(&priv->client->dev,
>  			"Write to IND_ACC_DATA failed when reading %u:0x%02x: %d\n",
>  			block, reg, ret);
> -		goto out_unlock;
> +		goto err;
>  	}
>
>  	*val = v;
>
> -out_unlock:
> -	mutex_unlock(&priv->reg_lock);
> -
> +err:
>  	if (ret && err)
>  		*err = ret;
>
> @@ -226,18 +220,18 @@ static int ub953_write_ind(struct ub953_data *priv, u8 block, u8 reg, u8 val,
>  	if (err && *err)
>  		return *err;
>
> -	mutex_lock(&priv->reg_lock);
> +	guard(mutex)(&priv->reg_lock);
>
>  	ret = ub953_select_ind_reg_block(priv, block);
>  	if (ret)
> -		goto out_unlock;
> +		goto err;
>
>  	ret = regmap_write(priv->regmap, UB953_REG_IND_ACC_ADDR, reg);
>  	if (ret) {
>  		dev_err(&priv->client->dev,
>  			"Write to IND_ACC_ADDR failed when writing %u:0x%02x: %d\n",
>  			block, reg, ret);
> -		goto out_unlock;
> +		goto err;
>  	}
>
>  	ret = regmap_write(priv->regmap, UB953_REG_IND_ACC_DATA, val);
> @@ -247,9 +241,7 @@ static int ub953_write_ind(struct ub953_data *priv, u8 block, u8 reg, u8 val,
>  			block, reg, ret);
>  	}
>
> -out_unlock:
> -	mutex_unlock(&priv->reg_lock);
> -
> +err:
>  	if (ret && err)
>  		*err = ret;
>
>
> --
> 2.34.1
>