Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Sender: Guenter Roeck <groeck7@gmail.com>
Message-ID: <ccbced2f-0258-cfd7-2f91-e246dadae8fb@roeck-us.net>
Date:   Tue, 25 Apr 2023 07:09:20 -0700
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.10.0
Subject: Re: [PATCH v1 2/2] hwmon: pmbus: Add ltc4286 driver
Content-Language: en-US
To:     Andi Shyti <andi.shyti@kernel.org>,
        Delphine CC Chiu <Delphine_CC_Chiu@Wiwynn.com>
Cc:     patrick@stwcx.xyz, Jean Delvare <jdelvare@suse.com>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        linux-i2c@vger.kernel.org, linux-hwmon@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20230424101352.28117-1-Delphine_CC_Chiu@Wiwynn.com>
 <20230424101352.28117-3-Delphine_CC_Chiu@Wiwynn.com>
 <20230425134537.pzsplcpkrog2552r@intel.intel>
From:   Guenter Roeck <linux@roeck-us.net>
In-Reply-To: <20230425134537.pzsplcpkrog2552r@intel.intel>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 4/25/23 06:45, Andi Shyti wrote:
> Hi Delphine,
> 
> On top of Guenter's comments,
> 
> [...]
> 
>> +config SENSORS_LTC4286
>> +	bool "Linear Technologies LTC4286"
>> +	help
>> +	  If you say yes here you get hardware monitoring support for Linear
>> +	  Technology LTC4286.
> 
> could you add a couple of words more here?
> 
> [...]
> 
>> +static int ltc4286_probe(struct i2c_client *client,
>> +			 const struct i2c_device_id *id)
>> +{
>> +	int ret;
>> +	u8 block_buffer[I2C_SMBUS_BLOCK_MAX + 1];
>> +	struct device *dev = &client->dev;
>> +	struct pmbus_driver_info *info;
>> +	u32 rsense;
>> +
>> +	ret = i2c_smbus_read_block_data(client, PMBUS_MFR_ID, block_buffer);
>> +	if (ret < 0) {
>> +		dev_err(&client->dev, "failed to read manufacturer id\n");
> 
> you can use dev_err_probe() here:
> 
> 	return dev_err_probe(&client->dev, err, "failed to read manufacturer id\n");
> 
>> +		return ret;
>> +	}
>> +
>> +	/* Refer to ltc4286 datasheet page 20
>> +	 * the default manufacturer id is LTC
>> +	 */
>> +	if (ret != LTC4286_MFR_ID_SIZE ||
>> +	    strncmp(block_buffer, "LTC", LTC4286_MFR_ID_SIZE)) {
>> +		dev_err(&client->dev, "unsupported manufacturer id\n");
>> +		return -ENODEV;
>> +	}
>> +
>> +	ret = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, block_buffer);
>> +	if (ret < 0) {
>> +		dev_err(&client->dev, "failed to read manufacturer model\n");
>> +		return ret;
>> +	}
> 
> Is this read really needed?
> 

It only makes sense if the returned string is actually validated.
Otherwise no.

Guenter