Hi Matt,
On 8/11/19 9:10 AM, Matt Ranostay wrote:
> Add current subpage data via the status register to the video
> frame in the last word of data, which seems to be unused
> undocumented reserved data.
I don't really understand from this description what is going on
here.
mlx90640_xfer() reads the buffer data from the i2c device, but
that data is split over two different addresses? Or does
0x8000 contain something else with a different meaning compared
to what is read from 0x400?
>
> Signed-off-by: Matt Ranostay <matt.ranostay@xxxxxxxxxxxx>
> ---
> drivers/media/i2c/video-i2c.c | 12 ++++++++++--
> 1 file changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/media/i2c/video-i2c.c b/drivers/media/i2c/video-i2c.c
> index 078141712c88..8bc7b228ba40 100644
> --- a/drivers/media/i2c/video-i2c.c
> +++ b/drivers/media/i2c/video-i2c.c
> @@ -168,8 +168,16 @@ static int amg88xx_xfer(struct video_i2c_data *data, char *buf)
>
> static int mlx90640_xfer(struct video_i2c_data *data, char *buf)
> {
> - return regmap_bulk_read(data->regmap, 0x400, buf,
> - data->chip->buffer_size);
> + int ret = regmap_bulk_read(data->regmap, 0x400, buf,
> + data->chip->buffer_size);
Shouldn't this be data->chip->buffer_size - size, since the last
'size' bytes will be overwritten anyway?
> + int size = data->chip->bpp / 8;
> +
> + if (ret)
> + return ret;
> +
> + /* read status register, which contains subpage that is read */
> + return regmap_bulk_read(data->regmap, 0x8000,
> + &buf[data->chip->buffer_size - size], size);
> }
>
> static int amg88xx_setup(struct video_i2c_data *data)
>
Regards,
Hans
