Re: [PATCH v2 16/23] staging: media: tegra-video: tegra20: simplify format align calculations

Mikko Perttunen
2025-09-22T04:44:52Z

On Saturday, September 6, 2025 10:53 PM Svyatoslav Ryhel wrote:
> Simplify format align calculations by slightly modifying supported formats
> structure.
>
> Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
> ---
> drivers/staging/media/tegra-video/tegra20.c | 41 ++++++++-------------
> 1 file changed, 16 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/staging/media/tegra-video/tegra20.c b/drivers/staging/media/tegra-video/tegra20.c
> index 6e0b3b728623..781c4e8ec856 100644
> --- a/drivers/staging/media/tegra-video/tegra20.c
> +++ b/drivers/staging/media/tegra-video/tegra20.c
> @@ -280,20 +280,8 @@ static void tegra20_fmt_align(struct v4l2_pix_format *pix, unsigned int bpp)
> pix->width = clamp(pix->width, TEGRA20_MIN_WIDTH, TEGRA20_MAX_WIDTH);
> pix->height = clamp(pix->height, TEGRA20_MIN_HEIGHT, TEGRA20_MAX_HEIGHT);
>
> - switch (pix->pixelformat) {
> - case V4L2_PIX_FMT_UYVY:
> - case V4L2_PIX_FMT_VYUY:
> - case V4L2_PIX_FMT_YUYV:
> - case V4L2_PIX_FMT_YVYU:
> - pix->bytesperline = roundup(pix->width, 2) * 2;
> - pix->sizeimage = roundup(pix->width, 2) * 2 * pix->height;
> - break;
> - case V4L2_PIX_FMT_YUV420:
> - case V4L2_PIX_FMT_YVU420:
> - pix->bytesperline = roundup(pix->width, 8);
> - pix->sizeimage = roundup(pix->width, 8) * pix->height * 3 / 2;
> - break;
> - }
> + pix->bytesperline = DIV_ROUND_UP(pix->width * bpp, 8);

Assuming the bpp is coming from the format table below, this changes the value of bytesperline for planar formats. With this it'll be (width * 12) / 8 i.e. width * 3/2, which doesn't sound right.

> + pix->sizeimage = pix->bytesperline * pix->height;
> }
>
> /*
> @@ -576,20 +564,23 @@ static const struct tegra_vi_ops tegra20_vi_ops = {
> .vi_stop_streaming = tegra20_vi_stop_streaming,
> };
>
> -#define TEGRA20_VIDEO_FMT(MBUS_CODE, BPP, FOURCC) \
> -{ \
> - .code = MEDIA_BUS_FMT_##MBUS_CODE, \
> - .bpp = BPP, \
> - .fourcc = V4L2_PIX_FMT_##FOURCC, \
> +#define TEGRA20_VIDEO_FMT(DATA_TYPE, BIT_WIDTH, MBUS_CODE, BPP, FOURCC) \
> +{ \
> + .img_dt = TEGRA_IMAGE_DT_##DATA_TYPE, \
> + .bit_width = BIT_WIDTH, \
> + .code = MEDIA_BUS_FMT_##MBUS_CODE, \
> + .bpp = BPP, \
> + .fourcc = V4L2_PIX_FMT_##FOURCC, \
> }
>
> static const struct tegra_video_format tegra20_video_formats[] = {
> - TEGRA20_VIDEO_FMT(UYVY8_2X8, 2, UYVY),
> - TEGRA20_VIDEO_FMT(VYUY8_2X8, 2, VYUY),
> - TEGRA20_VIDEO_FMT(YUYV8_2X8, 2, YUYV),
> - TEGRA20_VIDEO_FMT(YVYU8_2X8, 2, YVYU),
> - TEGRA20_VIDEO_FMT(UYVY8_2X8, 1, YUV420),
> - TEGRA20_VIDEO_FMT(UYVY8_2X8, 1, YVU420),
> + /* YUV422 */
> + TEGRA20_VIDEO_FMT(YUV422_8, 16, UYVY8_2X8, 16, UYVY),
> + TEGRA20_VIDEO_FMT(YUV422_8, 16, VYUY8_2X8, 16, VYUY),
> + TEGRA20_VIDEO_FMT(YUV422_8, 16, YUYV8_2X8, 16, YUYV),
> + TEGRA20_VIDEO_FMT(YUV422_8, 16, YVYU8_2X8, 16, YVYU),
> + TEGRA20_VIDEO_FMT(YUV422_8, 16, UYVY8_2X8, 12, YUV420),
> + TEGRA20_VIDEO_FMT(YUV422_8, 16, UYVY8_2X8, 12, YVU420),
> };
>
> const struct tegra_vi_soc tegra20_vi_soc = {
>