Re: [PATCH 1/2] hwmon: (lm90) split set&show temp as common codes

[Wei Ni <wni@nvidia.com>]

On 02/25/2014 02:32 PM, Guenter Roeck wrote:
> On 02/24/2014 10:21 PM, Wei Ni wrote:
>> Split set&show temp codes as common functions, so we can use it
>> directly when implement linux thermal framework.
>> And handle error return value for the lm90_select_remote_channel
>> and write_tempx, then set_temp8 and set_temp11 could return it
>> to user-space.
>>
>> Signed-off-by: Wei Ni <wni@nvidia.com>
>> Signed-off-by: Jean Delvare <khali@linux-fr.org>
>> ---
>>   drivers/hwmon/lm90.c |  170 ++++++++++++++++++++++++++++++++++----------------
>>   1 file changed, 115 insertions(+), 55 deletions(-)
>>
>> diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c
>> index c9ff08d..fb9e224 100644
>> --- a/drivers/hwmon/lm90.c
>> +++ b/drivers/hwmon/lm90.c
>> @@ -473,20 +473,29 @@ static int lm90_read16(struct i2c_client *client, u8 regh, u8 regl, u16 *value)
>>    * various registers have different meanings as a result of selecting a
>>    * non-default remote channel.
>>    */
>> -static inline void lm90_select_remote_channel(struct i2c_client *client,
>> -					      struct lm90_data *data,
>> -					      int channel)
>> +static inline int lm90_select_remote_channel(struct i2c_client *client,
>> +					     struct lm90_data *data,
>> +					     int channel)
>>   {
>>   	u8 config;
>> +	int err;
>>
>>   	if (data->kind == max6696) {
>>   		lm90_read_reg(client, LM90_REG_R_CONFIG1, &config);
>>   		config &= ~0x08;
>>   		if (channel)
>>   			config |= 0x08;
>> -		i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1,
>> -					  config);
>> +		err = i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1,
>> +						config);
>> +		if (err < 0) {
>> +			dev_err(&client->dev,
>> +				"Failed to select remote channel %d, err %d\n",
>> +				channel, err);
>> +			return err;
> 
> Not my call to make, but I really dislike all that new noisiness.
> Sure, it is ok to pass the error back, but in my opinion that is
> good enough. If every driver in the kernel would be that noisy,
> the log would be all but useless.

This was discussed in https://lkml.org/lkml/2013/12/227
Jean wish to catch and return write errors,then the set_temp8() could
return error to user-space.

Thanks.
Wei.

> 
> Guenter
>