Re: [PATCH 01/11] media: rcar-vin: Fix YUYV8_1X16 handling for CSI-2

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Jacopo,

Thank you for the patch.

On Fri, May 03, 2024 at 05:51:16PM +0200, Jacopo Mondi wrote:
> The YUYV8_1X16 and UYVY8_1X16 formats are treated as 'ITU-R
> BT.601/BT.1358 16-bit YCbCr-422 input' (YUV16 - 0x5) in the R-Car VIN
> driver and are thus disallowed when capturing frames from the R-Car
> CSI-2 interface according to the hardware manual.
> 
> As the 1X16 format variants are meant to be used with serial busses they
> have to be treated as 'YCbCr-422 8-bit data input' (0x1) when capturing
> from CSI-2, which is a valid setting for CSI-2.
> 
> Commit 78b3f9d75a62 ("media: rcar-vin: Add check that input interface
> and format are valid") disallowed capturing YUV16 when using the CSI-2
> interface. Fix this by using YUV8_BT601 for YCbCr422 when CSI-2 is in
> use.
> 
> Fixes: 78b3f9d75a62 ("media: rcar-vin: Add check that input interface and format are valid")
> Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
> ---
>  .../media/platform/renesas/rcar-vin/rcar-dma.c   | 16 +++++++++++++---
>  1 file changed, 13 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/media/platform/renesas/rcar-vin/rcar-dma.c b/drivers/media/platform/renesas/rcar-vin/rcar-dma.c
> index e2c40abc6d3d..21d5b2815e86 100644
> --- a/drivers/media/platform/renesas/rcar-vin/rcar-dma.c
> +++ b/drivers/media/platform/renesas/rcar-vin/rcar-dma.c
> @@ -742,12 +742,22 @@ static int rvin_setup(struct rvin_dev *vin)
>  	 */
>  	switch (vin->mbus_code) {
>  	case MEDIA_BUS_FMT_YUYV8_1X16:
> -		/* BT.601/BT.1358 16bit YCbCr422 */
> -		vnmc |= VNMC_INF_YUV16;
> +		if (vin->is_csi)
> +			/* YCbCr422 8-bit */
> +			vnmc |= VNMC_INF_YUV8_BT601;
> +		else
> +			/* BT.601/BT.1358 16bit YCbCr422 */
> +			vnmc |= VNMC_INF_YUV16;
>  		input_is_yuv = true;
>  		break;
>  	case MEDIA_BUS_FMT_UYVY8_1X16:
> -		vnmc |= VNMC_INF_YUV16 | VNMC_YCAL;
> +		if (vin->is_csi)
> +			/* YCbCr422 8-bit */
> +			vnmc |= VNMC_INF_YUV8_BT601;
> +		else
> +			/* BT.601/BT.1358 16bit YCbCr422 */
> +			vnmc |= VNMC_INF_YUV16;
> +		vnmc |= VNMC_YCAL;

You could also write

	case MEDIA_BUS_FMT_UYVY8_1X16:
		vnmc |= VNMC_YCAL;
		fallthrough;
	case MEDIA_BUS_FMT_YUYV8_1X16:
		if (vin->is_csi)
			/* YCbCr422 8-bit */
			vnmc |= VNMC_INF_YUV8_BT601;
		else
			/* BT.601/BT.1358 16bit YCbCr422 */
			vnmc |= VNMC_INF_YUV16;
		input_is_yuv = true;
		break;

Up to you.

On a side note, CSI-2 isn't supposed to support
MEDIA_BUS_FMT_YUYV8_1X16. The native format is MEDIA_BUS_FMT_UYVY8_1X16.
I wonder if we should trim down the list of supported formats. That's a
candidate for another patch though.

Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

>  		input_is_yuv = true;
>  		break;
>  	case MEDIA_BUS_FMT_UYVY8_2X8:

-- 
Regards,

Laurent Pinchart