| Message ID | b4aaa8a9-6a8b-6d5f-1aac-718e46fbcc7d@appeartv.com (mailing list archive) |
|---|---|
| State | Rejected |
| Headers | show |
Hi again,
Please disregard this patch!
I just saw that I had missed how adt7470_update_device() relies on
adt7470_read_temperatures().
In that context, the current code is working correctly.
And so I very humbly apologize for submitting a garbage patch.. Sorry!
-Martin
On 11/23/2016 12:34 PM, Martin Etnestad wrote:
> The ADT7470 driver uses num_temp_sensors to check whether or not it
> actually needs to read the temperature registers. However, the check
> currently has a broken comparison: "num_temp_sensors >= 0" instead of
> "num_temp_sensors == 0".
>
> This causes the driver to only read the temperature registers _once_
> because num_temp_sensors gets set to a non-negative number after the
> check, in the same function.
>
> Additionally, the check is currently done _after_ the measurement
> sequence has been completed. The check should be done before the
> measurement sequence is initiated, as it can be skipped altogether if
> num_temp_sensors is 0.
>
> This patch fixes the comparison and moves the check.
>
> Signed-off-by: Martin Etnestad <martin.etnestad@appeartv.com>
> ---
> drivers/hwmon/adt7470.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/hwmon/adt7470.c b/drivers/hwmon/adt7470.c
> index f5da39a..d1f9a54 100644
> --- a/drivers/hwmon/adt7470.c
> +++ b/drivers/hwmon/adt7470.c
> @@ -201,6 +201,10 @@ static int adt7470_read_temperatures(struct
> i2c_client *client,
> int i;
> u8 cfg, pwm[4], pwm_cfg[2];
>
> + /* only read sensors if we have to */
> + if (data->num_temp_sensors == 0)
> + return 0;
> +
> /* save pwm[1-4] config register */
> pwm_cfg[0] = i2c_smbus_read_byte_data(client,
> ADT7470_REG_PWM_CFG(0));
> pwm_cfg[1] = i2c_smbus_read_byte_data(client,
> ADT7470_REG_PWM_CFG(2));
> @@ -243,10 +247,6 @@ static int adt7470_read_temperatures(struct
> i2c_client *client,
> return -EAGAIN;
> }
>
> - /* Only count fans if we have to */
> - if (data->num_temp_sensors >= 0)
> - return 0;
> -
> for (i = 0; i < ADT7470_TEMP_COUNT; i++) {
> data->temp[i] = i2c_smbus_read_byte_data(client,
> ADT7470_TEMP_REG(i));
On 11/23/2016 03:34 AM, Martin Etnestad wrote: > The ADT7470 driver uses num_temp_sensors to check whether or not it > actually needs to read the temperature registers. However, the check > currently has a broken comparison: "num_temp_sensors >= 0" instead of > "num_temp_sensors == 0". > > This causes the driver to only read the temperature registers _once_ > because num_temp_sensors gets set to a non-negative number after the > check, in the same function. > > Additionally, the check is currently done _after_ the measurement > sequence has been completed. The check should be done before the > measurement sequence is initiated, as it can be skipped altogether if > num_temp_sensors is 0. > The check is there to ensure that num_temp_sensors is calculated only once. Your change breaks that. After the initial probe, temperature sensor values are read in adt7470_update_device(), and it is no longer necessary to do the read from adt7470_read_temperatures(). NACK, sorry. Guenter > This patch fixes the comparison and moves the check. > > Signed-off-by: Martin Etnestad <martin.etnestad@appeartv.com> > --- > drivers/hwmon/adt7470.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/drivers/hwmon/adt7470.c b/drivers/hwmon/adt7470.c > index f5da39a..d1f9a54 100644 > --- a/drivers/hwmon/adt7470.c > +++ b/drivers/hwmon/adt7470.c > @@ -201,6 +201,10 @@ static int adt7470_read_temperatures(struct i2c_client *client, > int i; > u8 cfg, pwm[4], pwm_cfg[2]; > > + /* only read sensors if we have to */ > + if (data->num_temp_sensors == 0) > + return 0; > + > /* save pwm[1-4] config register */ > pwm_cfg[0] = i2c_smbus_read_byte_data(client, ADT7470_REG_PWM_CFG(0)); > pwm_cfg[1] = i2c_smbus_read_byte_data(client, ADT7470_REG_PWM_CFG(2)); > @@ -243,10 +247,6 @@ static int adt7470_read_temperatures(struct i2c_client *client, > return -EAGAIN; > } > > - /* Only count fans if we have to */ > - if (data->num_temp_sensors >= 0) > - return 0; > - > for (i = 0; i < ADT7470_TEMP_COUNT; i++) { > data->temp[i] = i2c_smbus_read_byte_data(client, > ADT7470_TEMP_REG(i)); -- To unsubscribe from this list: send the line "unsubscribe linux-hwmon" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/hwmon/adt7470.c b/drivers/hwmon/adt7470.c index f5da39a..d1f9a54 100644 --- a/drivers/hwmon/adt7470.c +++ b/drivers/hwmon/adt7470.c @@ -201,6 +201,10 @@ static int adt7470_read_temperatures(struct i2c_client *client, int i; u8 cfg, pwm[4], pwm_cfg[2]; + /* only read sensors if we have to */ + if (data->num_temp_sensors == 0) + return 0; + /* save pwm[1-4] config register */ pwm_cfg[0] = i2c_smbus_read_byte_data(client, ADT7470_REG_PWM_CFG(0));
The ADT7470 driver uses num_temp_sensors to check whether or not it actually needs to read the temperature registers. However, the check currently has a broken comparison: "num_temp_sensors >= 0" instead of "num_temp_sensors == 0". This causes the driver to only read the temperature registers _once_ because num_temp_sensors gets set to a non-negative number after the check, in the same function. Additionally, the check is currently done _after_ the measurement sequence has been completed. The check should be done before the measurement sequence is initiated, as it can be skipped altogether if num_temp_sensors is 0. This patch fixes the comparison and moves the check. Signed-off-by: Martin Etnestad <martin.etnestad@appeartv.com> --- drivers/hwmon/adt7470.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) pwm_cfg[1] = i2c_smbus_read_byte_data(client, ADT7470_REG_PWM_CFG(2)); @@ -243,10 +247,6 @@ static int adt7470_read_temperatures(struct i2c_client *client, return -EAGAIN; } - /* Only count fans if we have to */ - if (data->num_temp_sensors >= 0) - return 0; - for (i = 0; i < ADT7470_TEMP_COUNT; i++) { data->temp[i] = i2c_smbus_read_byte_data(client, ADT7470_TEMP_REG(i));