Re: [PATCH v4 1/2] hwmon: w83627ehf driver cleanup

From: Jean Delvare
Date: Sun Jul 04 2010 - 07:25:07 EST

Hi Guenter,

On Sat, 3 Jul 2010 15:13:21 -0700, Guenter Roeck wrote:
> - Moved fan pwm register array pointers into per-instance data.
> - Only read fan pwm data for installed/supported fans.
> - Update fan max output and fan step output information from data in registers.
> - Create max_output and step_output attribute files only if respective
> fan pwm registers exist.
>
> Signed-off-by: Guenter Roeck <guenter.roeck@xxxxxxxxxxxx>
> ---
> drivers/hwmon/w83627ehf.c | 59 ++++++++++++++++++++++++++++++++++++++++++--
> 1 files changed, 56 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/hwmon/w83627ehf.c b/drivers/hwmon/w83627ehf.c
> index 0dcaba9..e01a3e9 100644
> --- a/drivers/hwmon/w83627ehf.c
> +++ b/drivers/hwmon/w83627ehf.c
> @@ -277,6 +277,11 @@ struct w83627ehf_data {
> struct device *hwmon_dev;
> struct mutex lock;
>
> + const u8 *REG_FAN_START_OUTPUT;
> + const u8 *REG_FAN_STOP_OUTPUT;
> + const u8 *REG_FAN_MAX_OUTPUT;
> + const u8 *REG_FAN_STEP_OUTPUT;
> +
> struct mutex update_lock;
> char valid; /* !=0 if following fields are valid */
> unsigned long last_updated; /* In jiffies */
> @@ -524,7 +529,10 @@ static struct w83627ehf_data *w83627ehf_update_device(struct device *dev)
> }
> }
>
> - for (i = 0; i < 4; i++) {
> + for (i = 0; i < data->pwm_num; i++) {
> + if (!(data->has_fan & (1 << i)))
> + continue;

I'm skeptical. data->has_fan refers to fan inputs, not fan outputs.
There is no guarantee that pwm1 is mapped to fan1, etc., so you can't
use data->has_fan to discard fan outputs.

> +
> /* pwmcfg, tolerance mapped for i=0, i=1 to same reg */
> if (i != 1) {
> pwmcfg = w83627ehf_read_value(data,
> @@ -546,6 +554,17 @@ static struct w83627ehf_data *w83627ehf_update_device(struct device *dev)
> W83627EHF_REG_FAN_STOP_OUTPUT[i]);
> data->fan_stop_time[i] = w83627ehf_read_value(data,
> W83627EHF_REG_FAN_STOP_TIME[i]);
> +
> + if (data->REG_FAN_MAX_OUTPUT[i] != 0xff)
> + data->fan_max_output[i] =
> + w83627ehf_read_value(data,
> + data->REG_FAN_MAX_OUTPUT[i]);
> +
> + if (data->REG_FAN_STEP_OUTPUT[i] != 0xff)
> + data->fan_step_output[i] =
> + w83627ehf_read_value(data,
> + data->REG_FAN_STEP_OUTPUT[i]);
> +

Huuu, wait a minute, So these values were supposedly exposed to
user-space, but were never read from their respective registers? So
this is a plain bug you're fixing?

Now I'm wondering, how useful is a feature that has been broken forever
and nobody ever complained?

> data->target_temp[i] =
> w83627ehf_read_value(data,
> W83627EHF_REG_TARGET[i]) &
> @@ -1126,7 +1145,7 @@ store_##reg(struct device *dev, struct device_attribute *attr, \
> u32 val = SENSORS_LIMIT(simple_strtoul(buf, NULL, 10), 1, 255); \
> mutex_lock(&data->update_lock); \
> data->reg[nr] = val; \
> - w83627ehf_write_value(data, W83627EHF_REG_##REG[nr], val); \
> + w83627ehf_write_value(data, data->REG_##REG[nr], val); \
> mutex_unlock(&data->update_lock); \
> return count; \
> }
> @@ -1206,12 +1225,26 @@ static struct sensor_device_attribute sda_sf3_arrays[] = {
> store_fan_stop_output, 1),
> SENSOR_ATTR(pwm3_stop_output, S_IWUSR | S_IRUGO, show_fan_stop_output,
> store_fan_stop_output, 2),
> +};
>
> - /* pwm1 and pwm3 don't support max and step settings */
> +
> +/*
> + * pwm1 and pwm3 don't support max and step settings on all chips.
> + * Need to check support while generating/removing attribute files.
> + */
> +static struct sensor_device_attribute sda_sf3_max_step_arrays[] = {
> + SENSOR_ATTR(pwm1_max_output, S_IWUSR | S_IRUGO, show_fan_max_output,
> + store_fan_max_output, 0),
> + SENSOR_ATTR(pwm1_step_output, S_IWUSR | S_IRUGO, show_fan_step_output,
> + store_fan_step_output, 0),
> SENSOR_ATTR(pwm2_max_output, S_IWUSR | S_IRUGO, show_fan_max_output,
> store_fan_max_output, 1),
> SENSOR_ATTR(pwm2_step_output, S_IWUSR | S_IRUGO, show_fan_step_output,
> store_fan_step_output, 1),
> + SENSOR_ATTR(pwm3_max_output, S_IWUSR | S_IRUGO, show_fan_max_output,
> + store_fan_max_output, 2),
> + SENSOR_ATTR(pwm3_step_output, S_IWUSR | S_IRUGO, show_fan_step_output,
> + store_fan_step_output, 2),
> };
>
> static ssize_t
> @@ -1235,6 +1268,12 @@ static void w83627ehf_device_remove_files(struct device *dev)
>
> for (i = 0; i < ARRAY_SIZE(sda_sf3_arrays); i++)
> device_remove_file(dev, &sda_sf3_arrays[i].dev_attr);
> + for (i = 0; i < ARRAY_SIZE(sda_sf3_max_step_arrays); i++) {
> + struct sensor_device_attribute *attr =
> + &sda_sf3_max_step_arrays[i];
> + if (data->REG_FAN_STEP_OUTPUT[attr->index] != 0xff)
> + device_remove_file(dev, &attr->dev_attr);
> + }
> for (i = 0; i < ARRAY_SIZE(sda_sf3_arrays_fan4); i++)
> device_remove_file(dev, &sda_sf3_arrays_fan4[i].dev_attr);
> for (i = 0; i < data->in_num; i++) {
> @@ -1352,6 +1391,11 @@ static int __devinit w83627ehf_probe(struct platform_device *pdev)
> data->in6_skip = !data->temp3_disable;
> }
>
> + data->REG_FAN_START_OUTPUT = W83627EHF_REG_FAN_START_OUTPUT;
> + data->REG_FAN_STOP_OUTPUT = W83627EHF_REG_FAN_STOP_OUTPUT;
> + data->REG_FAN_MAX_OUTPUT = W83627EHF_REG_FAN_MAX_OUTPUT;
> + data->REG_FAN_STEP_OUTPUT = W83627EHF_REG_FAN_STEP_OUTPUT;
> +
> /* Initialize the chip */
> w83627ehf_init_device(data);
>
> @@ -1440,6 +1484,15 @@ static int __devinit w83627ehf_probe(struct platform_device *pdev)
> &sda_sf3_arrays[i].dev_attr)))
> goto exit_remove;
>
> + for (i = 0; i < ARRAY_SIZE(sda_sf3_max_step_arrays); i++) {
> + struct sensor_device_attribute *attr =
> + &sda_sf3_max_step_arrays[i];
> + if (data->REG_FAN_STEP_OUTPUT[attr->index] != 0xff) {
> + err = device_create_file(dev, &attr->dev_attr);
> + if (err)
> + goto exit_remove;
> + }
> + }
> /* if fan4 is enabled create the sf3 files for it */
> if ((data->has_fan & (1 << 3)) && data->pwm_num >= 4)
> for (i = 0; i < ARRAY_SIZE(sda_sf3_arrays_fan4); i++) {


Nice cleanup overall.

--
Jean Delvare
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