Hi Jyoti and Vasyl,
Thanks for your review.
I will provide new patch version soon.
Thanks,
Andriy
On 06.10.21 03:16, Jyoti Bhayana wrote:
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Hi Vasyl,
Regarding below question, yes reading raw attribute should be blocked
if buffer is enabled for that sensor.
1. Should we block reading raw attribute and IIO buffer enabled, for for
SCMI sensor it can coexist?
PLease see https://elixir.bootlin.com/linux/latest/source/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c#L667
as well. It has
case IIO_CHAN_INFO_RAW:
ret = iio_device_claim_direct_mode(indio_dev);
if (ret)
return ret;
mutex_lock(&st->lock);
ret = inv_mpu6050_read_channel_data(indio_dev, chan, val);
mutex_unlock(&st->lock);
iio_device_release_direct_mode(indio_dev);
return ret;
Regarding the question below, the answer is yes.
2. Should we wrap reading raw attribute implementation in iio_dev->mlock
mutex?
Thanks, Jyoti
On Tue, Oct 5, 2021 at 5:52 AM Vasyl Vavrychuk
<vasyl.vavrychuk@xxxxxxxxxxxxxxx> wrote:
Hi, Jyoti,
In the code below, why is the logic of enabling and disabling the
sensor in this function? Generally the function to read the sensor
value is just used for the code to read the sensor values ? and not
enable/disable the sensor
But to read sensor value we have to enable it first. Other way to enable
sensor we found is, for example:
echo 1 > /sys/bus/iio/devices/.../scan_elements/in_anglvel_x_en
But, this command is related to IIO buffers use.
Other sensors drivers enable/disable sensor in read raw too, for
example, drivers/iio/accel/kxcjk-1013.c has:
case IIO_CHAN_INFO_RAW:
mutex_lock(&data->mutex);
if (iio_buffer_enabled(indio_dev))
ret = -EBUSY;
else {
ret = kxcjk1013_set_power_state(data, true);
... reading ...
ret = kxcjk1013_set_power_state(data, false);
}
mutex_unlock(&data->mutex);
But, after looking on this code I have some questions:
1. Should we block reading raw attribute and IIO buffer enabled, for for
SCMI sensor it can coexist?
2. Should we wrap reading raw attribute implementation in iio_dev->mlock
mutex?
case IIO_CHAN_INFO_RAW:
+ sensor_config = FIELD_PREP(SCMI_SENS_CFG_SENSOR_ENABLED_MASK,
+ SCMI_SENS_CFG_SENSOR_ENABLE);
+ err = sensor->sensor_ops->config_set(
+ sensor->ph, sensor->sensor_info->id, sensor_config);
+ if (err) {
+ dev_err(&iio_dev->dev,
+ "Error in enabling sensor %s err %d",
+ sensor->sensor_info->name, err);
+ return err;
+ }
+
+ err = sensor->sensor_ops->reading_get_timestamped(
+ sensor->ph, sensor->sensor_info->id,
+ sensor->sensor_info->num_axis, readings);
+ if (err) {
+ dev_err(&iio_dev->dev,
+ "Error in reading raw attribute for sensor %s err %d",
+ sensor->sensor_info->name, err);
+ return err;
+ }
+
+ sensor_config = FIELD_PREP(SCMI_SENS_CFG_SENSOR_ENABLED_MASK,
+ SCMI_SENS_CFG_SENSOR_DISABLE);
+ err = sensor->sensor_ops->config_set(
+ sensor->ph, sensor->sensor_info->id, sensor_config);
+ if (err) {
+ dev_err(&iio_dev->dev,
+ "Error in enabling sensor %s err %d",
+ sensor->sensor_info->name, err);
+ return err;
+ }
+ /* Check if raw value fits 32 bits */
+ if (readings[ch->scan_index].value < INT_MIN ||
+ readings[ch->scan_index].value > INT_MAX)
+ return -ERANGE;
+ /* Use 32-bit value, since practically there is no need in 64 bits */
+ *val = (int)readings[ch->scan_index].value;
+ return IIO_VAL_INT;
