Re: [PATCH v2 2/2] media: vsp1: Document max_width restriction on UDS
From: Laurent Pinchart
Date: Fri Sep 14 2018 - 10:48:41 EST
Hi Kieran,
Thank you for the patch.
On Friday, 14 September 2018 17:26:52 EEST Kieran Bingham wrote:
> The UDS is currently restricted based on a partition size of 256 pixels.
> Document the actual restrictions, but don't increase the implementation.
>
> The extended partition algorithm may later choose to utilise a larger
> partition size to support overlapping partitions which will improve the
> quality of the output images.
>
> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> ---
> drivers/media/platform/vsp1/vsp1_uds.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/drivers/media/platform/vsp1/vsp1_uds.c
> b/drivers/media/platform/vsp1/vsp1_uds.c index 75c613050151..e8340de85813
> 100644
> --- a/drivers/media/platform/vsp1/vsp1_uds.c
> +++ b/drivers/media/platform/vsp1/vsp1_uds.c
> @@ -342,6 +342,14 @@ static unsigned int uds_max_width(struct vsp1_entity
> *entity, UDS_PAD_SOURCE);
> hscale = output->width / input->width;
>
> + /*
> + * The maximum width of the UDS is 304 pixels. These are input pixels
> + * in the event of up-scaling, and output pixels in the event of
> + * downscaling.
> + *
> + * To support overlapping parition windows we clamp at units of 256 and
> + * the remaining pixels are reserved.
> + */
> if (hscale <= 2)
> return 256;
> else if (hscale <= 4)
--
Regards,
Laurent Pinchart