On Sat, Sep 14, 2024 at 12:36:11PM +0100, Jonathan Cameron wrote: > On Fri, 23 Aug 2024 19:20:17 +0200 > Vasileios Amoiridis <vassilisamir@xxxxxxxxx> wrote: > > > As it was reported and discussed here [1], storing the sensor data in an > > endian aware s32 buffer is not optimal. Advertising the timestamp as an > > addition of 2 s32 variables which is also implied is again not the best > > practice. For that reason, change the s32 sensor_data buffer to a char > > buffer with an extra value for the timestamp (as it is common practice). > > > > [1]: https://lore.kernel.org/linux-iio/73d13cc0-afb9-4306-b498-5d821728c3ba@stanley.mountain/ > > > > Signed-off-by: Vasileios Amoiridis <vassilisamir@xxxxxxxxx> > Hi. > Thanks for poking. Looks like I'd accidentally marked this one handled > without actually doing so :( > Hi Jonathan, No problem at all!!! > > --- > > drivers/iio/pressure/bmp280-core.c | 43 +++++++++++++++++------------- > > drivers/iio/pressure/bmp280.h | 5 +++- > > 2 files changed, 28 insertions(+), 20 deletions(-) > > > > diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c > > index 3deaa57bb3f5..71e481c2f30d 100644 > > --- a/drivers/iio/pressure/bmp280-core.c > > +++ b/drivers/iio/pressure/bmp280-core.c > > @@ -1035,7 +1035,8 @@ static irqreturn_t bmp280_trigger_handler(int irq, void *p) > > goto out; > > } > > > > - data->sensor_data[1] = bmp280_compensate_temp(data, adc_temp); > > + ret = bmp280_compensate_temp(data, adc_temp); > > + memcpy(&data->buffer.buf[4], &ret, 4); > > The 4's in here are magic indexes. Probably use sizeof(s32) in both cases. > Maybe for the first one make the fact it's after an s32 explicit with > &data->buffer.buf[1 * sizeof(s32)] > > Of carry an offset through the code that you update when you fill in part of > the buffer. That is probably cleaner. > > int offset = 0; > stuff > offset += sizeof(s32); > mempcy(&data->bufer.buf[offset], &ret, 4); > > if offset is used for a later entry then add the new element. > > Looks nice. I could also move both memcpy() after the if's so in case there is an error I save myself from memcpy() once for no reason. > > > > /* Pressure calculations */ > > adc_press = FIELD_GET(BMP280_MEAS_TRIM_MASK, get_unaligned_be24(&data->buf[0])); > > @@ -1045,10 +1046,10 @@ static irqreturn_t bmp280_trigger_handler(int irq, void *p) > > } > > > > t_fine = bmp280_calc_t_fine(data, adc_temp); > > + ret = bmp280_compensate_press(data, adc_press, t_fine); > > + memcpy(&data->buffer.buf[0], &ret, 4); > > > > - data->sensor_data[0] = bmp280_compensate_press(data, adc_press, t_fine); > > - > > - iio_push_to_buffers_with_timestamp(indio_dev, &data->sensor_data, > > + iio_push_to_buffers_with_timestamp(indio_dev, &data->buffer, > > iio_get_time_ns(indio_dev)); > > > > out: > > @@ -1148,7 +1149,8 @@ static irqreturn_t bme280_trigger_handler(int irq, void *p) > > goto out; > > } > > > > - data->sensor_data[1] = bmp280_compensate_temp(data, adc_temp); > > + ret = bmp280_compensate_temp(data, adc_temp); > > + memcpy(&data->buffer.buf[4], &ret, 4); > > > > /* Pressure calculations */ > > adc_press = FIELD_GET(BMP280_MEAS_TRIM_MASK, get_unaligned_be24(&data->buf[0])); > > @@ -1158,8 +1160,8 @@ static irqreturn_t bme280_trigger_handler(int irq, void *p) > > } > > > > t_fine = bmp280_calc_t_fine(data, adc_temp); > > - > > - data->sensor_data[0] = bmp280_compensate_press(data, adc_press, t_fine); > > + ret = bmp280_compensate_press(data, adc_press, t_fine); > > + memcpy(&data->buffer.buf[0], &ret, 4); > > > > /* Humidity calculations */ > > adc_humidity = get_unaligned_be16(&data->buf[6]); > > @@ -1168,9 +1170,11 @@ static irqreturn_t bme280_trigger_handler(int irq, void *p) > > dev_err(data->dev, "reading humidity skipped\n"); > > goto out; > > } > > - data->sensor_data[2] = bme280_compensate_humidity(data, adc_humidity, t_fine); > > > > - iio_push_to_buffers_with_timestamp(indio_dev, &data->sensor_data, > > + ret = bme280_compensate_humidity(data, adc_humidity, t_fine); > > + memcpy(&data->buffer.buf[8], &ret, 4); > as above, but here it is I guess after 2 other elements, so > > 2 * sizeof(s32) > > > + > > + iio_push_to_buffers_with_timestamp(indio_dev, &data->buffer, > > iio_get_time_ns(indio_dev)); > > > > out: > > @@ -1628,7 +1632,8 @@ static irqreturn_t bmp380_trigger_handler(int irq, void *p) > > goto out; > > } > > > > - data->sensor_data[1] = bmp380_compensate_temp(data, adc_temp); > > + ret = bmp380_compensate_temp(data, adc_temp); > > + memcpy(&data->buffer.buf[4], &ret, 4); > > > > /* Pressure calculations */ > > adc_press = get_unaligned_le24(&data->buf[0]); > > @@ -1638,10 +1643,10 @@ static irqreturn_t bmp380_trigger_handler(int irq, void *p) > > } > > > > t_fine = bmp380_calc_t_fine(data, adc_temp); > > + ret = bmp380_compensate_press(data, adc_press, t_fine); > > + memcpy(&data->buffer.buf[0], &ret, 4); > > > > - data->sensor_data[0] = bmp380_compensate_press(data, adc_press, t_fine); > > - > > - iio_push_to_buffers_with_timestamp(indio_dev, &data->sensor_data, > > + iio_push_to_buffers_with_timestamp(indio_dev, &data->buffer, > > iio_get_time_ns(indio_dev)); > > > > out: > > @@ -2203,12 +2208,12 @@ static irqreturn_t bmp580_trigger_handler(int irq, void *p) > > } > > > > /* Temperature calculations */ > > - memcpy(&data->sensor_data[1], &data->buf[0], 3); > > + memcpy(&data->buffer.buf[4], &data->buf[0], 3); > > > > /* Pressure calculations */ > > - memcpy(&data->sensor_data[0], &data->buf[3], 3); > > + memcpy(&data->buffer.buf[0], &data->buf[3], 3); > > > - iio_push_to_buffers_with_timestamp(indio_dev, &data->sensor_data, > > + iio_push_to_buffers_with_timestamp(indio_dev, &data->buffer, > > iio_get_time_ns(indio_dev)); > > > > out: > > @@ -2522,15 +2527,15 @@ static irqreturn_t bmp180_trigger_handler(int irq, void *p) > > if (ret) > > goto out; > > > > - data->sensor_data[1] = chan_value; > > + memcpy(&data->buffer.buf[4], &chan_value, 4); > > > > ret = bmp180_read_press(data, &chan_value); > > if (ret) > > goto out; > > > > - data->sensor_data[0] = chan_value; > > + memcpy(&data->buffer.buf[0], &chan_value, 4); > > > > - iio_push_to_buffers_with_timestamp(indio_dev, &data->sensor_data, > > + iio_push_to_buffers_with_timestamp(indio_dev, &data->buffer, > > iio_get_time_ns(indio_dev)); > > > > out: > > diff --git a/drivers/iio/pressure/bmp280.h b/drivers/iio/pressure/bmp280.h > > index ccacc67c1473..a853b6d5bdfa 100644 > > --- a/drivers/iio/pressure/bmp280.h > > +++ b/drivers/iio/pressure/bmp280.h > > @@ -411,7 +411,10 @@ struct bmp280_data { > > * Data to push to userspace triggered buffer. Up to 3 channels and > > * s64 timestamp, aligned. > > */ > > - s32 sensor_data[6] __aligned(8); > > + struct { > > + u8 buf[12]; > > + s64 ts __aligned(8); > > We have a new aligned_s64 that is cleaner for these cases. It's only > in my togreg branch currently though so you'll need to base on that > to use it. > > Jonathan > > Looks nice, I will try it. Cheers, Vasilis > > + } buffer; > > > > /* > > * DMA (thus cache coherency maintenance) may require the >
