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Message-ID: <5237FEEF.9050308@nvidia.com>
Date: Tue, 17 Sep 2013 15:04:15 +0800
From: Wei Ni <wni@...dia.com>
To: Jean Delvare <khali@...ux-fr.org>
CC: "linux@...ck-us.net" <linux@...ck-us.net>,
"lm-sensors@...sensors.org" <lm-sensors@...sensors.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"linux-tegra@...r.kernel.org" <linux-tegra@...r.kernel.org>
Subject: Re: [PATCH RESEND v4] hwmon: (lm90) split set&show temp as common
codes
On 09/17/2013 03:29 AM, Jean Delvare wrote:
> Hi Wei,
>
> On Tue, 6 Aug 2013 18:36:57 +0800, 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@...dia.com>
>> ---
>> drivers/hwmon/lm90.c | 150 +++++++++++++++++++++++++++++++++-----------------
>> 1 file changed, 99 insertions(+), 51 deletions(-)
>>
>> diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c
>> index cdff742..6de8e01 100644
>> --- a/drivers/hwmon/lm90.c
>> +++ b/drivers/hwmon/lm90.c
>> @@ -422,20 +422,29 @@ 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,
>> +static inline int lm90_select_remote_channel(struct i2c_client *client,
>> struct lm90_data *data,
>> int channel)
>> {
>> u8 config;
>> + int err = 0;
>
> You don't have to initialize err, as you return immediately when an
> error happens. You can just...
Got it, I will change it.
>
>>
>> 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;
>> + }
>> }
>> +
>> + return err;
>
> ... return 0 here.
>
>> }
>>
>> /*
>> @@ -702,29 +711,34 @@ static u16 temp_to_u16_adt7461(struct lm90_data *data, long val)
>> * Sysfs stuff
>> */
>>
>> -static ssize_t show_temp8(struct device *dev, struct device_attribute *devattr,
>> - char *buf)
>> +static int read_temp8(struct device *dev, int index)
>> {
>> - struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
>> struct lm90_data *data = lm90_update_device(dev);
>> int temp;
>>
>> if (data->kind == adt7461)
>> - temp = temp_from_u8_adt7461(data, data->temp8[attr->index]);
>> + temp = temp_from_u8_adt7461(data, data->temp8[index]);
>> else if (data->kind == max6646)
>> - temp = temp_from_u8(data->temp8[attr->index]);
>> + temp = temp_from_u8(data->temp8[index]);
>> else
>> - temp = temp_from_s8(data->temp8[attr->index]);
>> + temp = temp_from_s8(data->temp8[index]);
>>
>> /* +16 degrees offset for temp2 for the LM99 */
>> - if (data->kind == lm99 && attr->index == 3)
>> + if (data->kind == lm99 && index == 3)
>> temp += 16000;
>>
>> - return sprintf(buf, "%d\n", temp);
>> + return temp;
>> }
>>
>> -static ssize_t set_temp8(struct device *dev, struct device_attribute *devattr,
>> - const char *buf, size_t count)
>> +static ssize_t show_temp8(struct device *dev, struct device_attribute *devattr,
>> + char *buf)
>> +{
>> + struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
>> +
>> + return sprintf(buf, "%d\n", read_temp8(dev, attr->index));
>> +}
>> +
>> +static int write_temp8(struct device *dev, int index, long val)
>> {
>> static const u8 reg[8] = {
>> LM90_REG_W_LOCAL_LOW,
>> @@ -737,60 +751,79 @@ static ssize_t set_temp8(struct device *dev, struct device_attribute *devattr,
>> MAX6659_REG_W_REMOTE_EMERG,
>> };
>>
>> - struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
>> struct i2c_client *client = to_i2c_client(dev);
>> struct lm90_data *data = i2c_get_clientdata(client);
>> - int nr = attr->index;
>> - long val;
>> int err;
>>
>> - err = kstrtol(buf, 10, &val);
>> - if (err < 0)
>> - return err;
>> -
>> /* +16 degrees offset for temp2 for the LM99 */
>> - if (data->kind == lm99 && attr->index == 3)
>> + if (data->kind == lm99 && index == 3)
>> val -= 16000;
>>
>> mutex_lock(&data->update_lock);
>> if (data->kind == adt7461)
>> - data->temp8[nr] = temp_to_u8_adt7461(data, val);
>> + data->temp8[index] = temp_to_u8_adt7461(data, val);
>> else if (data->kind == max6646)
>> - data->temp8[nr] = temp_to_u8(val);
>> + data->temp8[index] = temp_to_u8(val);
>> else
>> - data->temp8[nr] = temp_to_s8(val);
>> -
>> - lm90_select_remote_channel(client, data, nr >= 6);
>> - i2c_smbus_write_byte_data(client, reg[nr], data->temp8[nr]);
>> - lm90_select_remote_channel(client, data, 0);
>> + data->temp8[index] = temp_to_s8(val);
>>
>> + err = lm90_select_remote_channel(client, data, index >= 6);
>> + err |= i2c_smbus_write_byte_data(client, reg[index], data->temp8[index]);
>> + err |= lm90_select_remote_channel(client, data, 0);
>
> You can't use |= for error codes. Imagine that
> lm90_select_remote_channel() returns -EIO (-5) and
> i2c_smbus_write_byte_data() returns -EAGAIN (-11), err will have value
> -EPERM (-1) which makes no sense. You have to report errors as soon as
> they happen so that the error code isn't lost.
>
> What you can do is:
>
> if ((err = f1(...)) ||
> (err = f2(...)) ||
> (err = f3(...))) {
> dev_err(...);
> return err;
> }
>
> I think checkpatch will complain about that construct but me, I'm fine
> with it.
Ok, I will do it.
>
>> + if (err)
>> + dev_err(dev, "write_temp8 failed!\n");
>> mutex_unlock(&data->update_lock);
>> +
>> + return err;
>> +}
>> +
>> +static ssize_t set_temp8(struct device *dev, struct device_attribute *devattr,
>> + const char *buf, size_t count)
>> +{
>> + struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
>> + int index = attr->index;
>> + long val;
>> + int err;
>> +
>> + err = kstrtol(buf, 10, &val);
>> + if (err < 0)
>> + return err;
>> +
>> + err = write_temp8(dev, index, val);
>> + if (err < 0)
>> + return err;
>> +
>> return count;
>> }
>>
>> -static ssize_t show_temp11(struct device *dev, struct device_attribute *devattr,
>> - char *buf)
>> +static int read_temp11(struct device *dev, int index)
>> {
>> - struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
>> struct lm90_data *data = lm90_update_device(dev);
>> int temp;
>>
>> if (data->kind == adt7461)
>> - temp = temp_from_u16_adt7461(data, data->temp11[attr->index]);
>> + temp = temp_from_u16_adt7461(data, data->temp11[index]);
>> else if (data->kind == max6646)
>> - temp = temp_from_u16(data->temp11[attr->index]);
>> + temp = temp_from_u16(data->temp11[index]);
>> else
>> - temp = temp_from_s16(data->temp11[attr->index]);
>> + temp = temp_from_s16(data->temp11[index]);
>>
>> /* +16 degrees offset for temp2 for the LM99 */
>> - if (data->kind == lm99 && attr->index <= 2)
>> + if (data->kind == lm99 && index <= 2)
>> temp += 16000;
>>
>> - return sprintf(buf, "%d\n", temp);
>> + return temp;
>> }
>>
>> -static ssize_t set_temp11(struct device *dev, struct device_attribute *devattr,
>> - const char *buf, size_t count)
>> +static ssize_t show_temp11(struct device *dev, struct device_attribute *devattr,
>> + char *buf)
>> +{
>> + struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
>> +
>> + return sprintf(buf, "%d\n", read_temp11(dev, attr->index));
>> +}
>> +
>> +static int write_temp11(struct device *dev, int nr, int index, long val)
>> {
>> struct {
>> u8 high;
>> @@ -804,18 +837,10 @@ static ssize_t set_temp11(struct device *dev, struct device_attribute *devattr,
>> { LM90_REG_W_REMOTE_HIGHH, LM90_REG_W_REMOTE_HIGHL, 1 }
>> };
>>
>> - struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
>> struct i2c_client *client = to_i2c_client(dev);
>> struct lm90_data *data = i2c_get_clientdata(client);
>> - int nr = attr->nr;
>> - int index = attr->index;
>> - long val;
>> int err;
>>
>> - err = kstrtol(buf, 10, &val);
>> - if (err < 0)
>> - return err;
>> -
>> /* +16 degrees offset for temp2 for the LM99 */
>> if (data->kind == lm99 && index <= 2)
>> val -= 16000;
>> @@ -830,15 +855,38 @@ static ssize_t set_temp11(struct device *dev, struct device_attribute *devattr,
>> else
>> data->temp11[index] = temp_to_s8(val) << 8;
>>
>> - lm90_select_remote_channel(client, data, reg[nr].channel);
>> - i2c_smbus_write_byte_data(client, reg[nr].high,
>> + err = lm90_select_remote_channel(client, data, reg[nr].channel);
>> + err |= i2c_smbus_write_byte_data(client, reg[nr].high,
>> data->temp11[index] >> 8);
>> if (data->flags & LM90_HAVE_REM_LIMIT_EXT)
>> - i2c_smbus_write_byte_data(client, reg[nr].low,
>> - data->temp11[index] & 0xff);
>> - lm90_select_remote_channel(client, data, 0);
>> + err |= i2c_smbus_write_byte_data(client, reg[nr].low,
>> + data->temp11[index] & 0xff);
>> + err |= lm90_select_remote_channel(client, data, 0);
>> + if (err)
>> + dev_err(dev, "write_temp11 failed !\n");
>
> Same here, you can't use |=.
>
> Also, no space needed before exclamation marks in English.
Oh, you reviewed so carefully, thanks.
>
>>
>> mutex_unlock(&data->update_lock);
>> +
>> + return err;
>> +}
>> +
>> +static ssize_t set_temp11(struct device *dev, struct device_attribute *devattr,
>> + const char *buf, size_t count)
>> +{
>> + struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
>> + int nr = attr->nr;
>> + int index = attr->index;
>> + long val;
>> + int err;
>> +
>> + err = kstrtol(buf, 10, &val);
>> + if (err < 0)
>> + return err;
>> +
>> + err = write_temp11(dev, nr, index, val);
>> + if (err < 0)
>> + return err;
>> +
>> return count;
>> }
>>
>
> --
> Jean Delvare
> --
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