Re: [PATCH] iio: hid-sensor-rotation: Fix quaternion data not correct

[Jonathan Cameron <jic23@kernel.org>]

On Wed, 20 Jan 2021 15:49:09 +0800
Ye Xiang <xiang.ye@intel.com> wrote:

> Because the data of HID_USAGE_SENSOR_ORIENT_QUATERNION defined by ISH FW
> is s16, but quaternion data type is in_rot_quaternion_type(le:s16/32X4>>0),
> need to transform data type from s16 to s32
> 
> Signed-off-by: Ye Xiang <xiang.ye@intel.com>

Hi Ye Xiang,

So from a quick check of the "HID Sensor Usages" spec, I 'think' that we can only
have s16 and s32 for this type of channel in which case this fix is sufficient for
all possible cases.

Also, please figure out a best estimate for a
Fixes: tag as that will help with backporting this.

Thanks,

Jonathan


> ---
>  drivers/iio/orientation/hid-sensor-rotation.c | 13 ++++++++++---
>  1 file changed, 10 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/iio/orientation/hid-sensor-rotation.c b/drivers/iio/orientation/hid-sensor-rotation.c
> index b0245b3b7ffc..cf7f57a47681 100644
> --- a/drivers/iio/orientation/hid-sensor-rotation.c
> +++ b/drivers/iio/orientation/hid-sensor-rotation.c
> @@ -21,7 +21,7 @@ struct dev_rot_state {
>  	struct hid_sensor_common common_attributes;
>  	struct hid_sensor_hub_attribute_info quaternion;
>  	struct {
> -		u32 sampled_vals[4] __aligned(16);
> +		s32 sampled_vals[4] __aligned(16);
>  		u64 timestamp __aligned(8);
>  	} scan;
>  	int scale_pre_decml;
> @@ -175,8 +175,15 @@ static int dev_rot_capture_sample(struct hid_sensor_hub_device *hsdev,
>  	struct dev_rot_state *rot_state = iio_priv(indio_dev);
>  
>  	if (usage_id == HID_USAGE_SENSOR_ORIENT_QUATERNION) {
> -		memcpy(&rot_state->scan.sampled_vals, raw_data,
> -		       sizeof(rot_state->scan.sampled_vals));
> +		if (raw_len / 4 == sizeof(s16)) {
> +			rot_state->scan.sampled_vals[0] = ((s16 *)raw_data)[0];
> +			rot_state->scan.sampled_vals[1] = ((s16 *)raw_data)[1];
> +			rot_state->scan.sampled_vals[2] = ((s16 *)raw_data)[2];
> +			rot_state->scan.sampled_vals[3] = ((s16 *)raw_data)[3];
> +		} else {
> +			memcpy(&rot_state->scan.sampled_vals, raw_data,
> +			       sizeof(rot_state->scan.sampled_vals));
> +		}
>  
>  		dev_dbg(&indio_dev->dev, "Recd Quat len:%zu::%zu\n", raw_len,
>  			sizeof(rot_state->scan.sampled_vals));