Re: [PATCH v4 2/6] media: qcom: iris: add QC10C & P010 buffer size calculations

From: bod

Date: Mon May 25 2026 - 19:32:55 EST

On 2026-05-21 11:24 +0200, Neil Armstrong wrote:
> The P010 (YUV format with 16-bits per pixel with interleaved UV)
> and QC10C (P010 compressed mode similar to QC08C) requires specific
> buffer calculations to allocate the right buffer size for the DPB
> (decoded picture buffer) frames and frames consumed by userspace.
>
> Similar to 8bit, the 10bit DPB frames uses QC10C format.
>
> Signed-off-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx>
> ---
> drivers/media/platform/qcom/iris/iris_buffer.c | 195 ++++++++++++++++++++++++-
> 1 file changed, 194 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/media/platform/qcom/iris/iris_buffer.c b/drivers/media/platform/qcom/iris/iris_buffer.c
> index ef7f6f931557..fbe2dd87f0d6 100644
> --- a/drivers/media/platform/qcom/iris/iris_buffer.c
> +++ b/drivers/media/platform/qcom/iris/iris_buffer.c
> @@ -15,8 +15,11 @@
> #define MAX_WIDTH 4096
> #define MAX_HEIGHT 2304
> #define Y_STRIDE_ALIGN 128
> +#define Y_STRIDE_ALIGN_P010 256
> #define UV_STRIDE_ALIGN 128
> +#define UV_STRIDE_ALIGN_P010 256
> #define Y_SCANLINE_ALIGN 32
> +#define Y_SCANLINE_ALIGN_QC10C 16
> #define UV_SCANLINE_ALIGN 16
> #define UV_SCANLINE_ALIGN_QC08C 32
> #define META_STRIDE_ALIGNED 64
> @@ -80,6 +83,63 @@ static u32 iris_yuv_buffer_size_nv12(struct iris_inst *inst)
> return ALIGN(y_plane + uv_plane, PIXELS_4K);
> }
>
> +/*
> + * P010:
> + * YUV 4:2:0 image with a plane of 10 bit Y samples followed
> + * by an interleaved U/V plane containing 10 bit 2x2 subsampled
> + * colour difference samples.
> + *
> + * <-Y/UV_Stride (aligned to 256)->
> + * <----- Width*2 ------->
> + * Y Y Y Y Y Y Y Y Y Y Y Y . . . . ^ ^
> + * Y Y Y Y Y Y Y Y Y Y Y Y . . . . | |
> + * Y Y Y Y Y Y Y Y Y Y Y Y . . . . Height |
> + * Y Y Y Y Y Y Y Y Y Y Y Y . . . . | y_scanlines (aligned to 32)
> + * Y Y Y Y Y Y Y Y Y Y Y Y . . . . | |
> + * Y Y Y Y Y Y Y Y Y Y Y Y . . . . | |
> + * Y Y Y Y Y Y Y Y Y Y Y Y . . . . | |
> + * Y Y Y Y Y Y Y Y Y Y Y Y . . . . V |
> + * . . . . . . . . . . . . . . . . |
> + * . . . . . . . . . . . . . . . . |
> + * . . . . . . . . . . . . . . . . |
> + * . . . . . . . . . . . . . . . . V
> + * U V U V U V U V U V U V . . . . ^
> + * U V U V U V U V U V U V . . . . |
> + * U V U V U V U V U V U V . . . . |
> + * U V U V U V U V U V U V . . . . uv_scanlines (aligned to 16)
> + * . . . . . . . . . . . . . . . . |
> + * . . . . . . . . . . . . . . . . V
> + * . . . . . . . . . . . . . . . . --> Buffer size aligned to 4K
> + *
> + * y_stride : Width*2 aligned to 256
> + * uv_stride : Width*2 aligned to 256
> + * y_scanlines: Height aligned to 32
> + * uv_scanlines: Height/2 aligned to 16
> + * Total size = align((y_stride * y_scanlines
> + * + uv_stride * uv_scanlines , 4096)
> + *
> + * Note: All the alignments are hardware requirements.
> + */
> +static u32 iris_yuv_buffer_size_p010(struct iris_inst *inst)
> +{
> + u32 y_plane, uv_plane, y_stride, uv_stride, y_scanlines, uv_scanlines;
> + struct v4l2_format *f;
> +
> + if (inst->domain == DECODER)
> + f = inst->fmt_dst;
> + else
> + f = inst->fmt_src;
> +
> + y_stride = ALIGN(f->fmt.pix_mp.width * 2, Y_STRIDE_ALIGN_P010);
> + uv_stride = ALIGN(f->fmt.pix_mp.width * 2, UV_STRIDE_ALIGN_P010);
> + y_scanlines = ALIGN(f->fmt.pix_mp.height, Y_SCANLINE_ALIGN);
> + uv_scanlines = ALIGN((f->fmt.pix_mp.height + 1) >> 1, UV_SCANLINE_ALIGN);
> + y_plane = y_stride * y_scanlines;
> + uv_plane = uv_stride * uv_scanlines;
> +
> + return ALIGN(y_plane + uv_plane, PIXELS_4K);
> +}
> +
> /*
> * QC08C:
> * Compressed Macro-tile format for NV12.
> @@ -204,6 +264,132 @@ static u32 iris_yuv_buffer_size_qc08c(struct iris_inst *inst)
> return ALIGN(y_meta_plane + y_plane + uv_meta_plane + uv_plane, PIXELS_4K);
> }
>
> +/*
> + * QC10C:
> + * UBWC-compressed format for P010.
> + * Contains 4 planes in the following order -
> + * (A) Y_Meta_Plane
> + * (B) Y_UBWC_Plane
> + * (C) UV_Meta_Plane
> + * (D) UV_UBWC_Plane
> + *
> + * Y_Meta_Plane consists of meta information to decode compressed
> + * tile data in Y_UBWC_Plane.
> + * Y_UBWC_Plane consists of Y data in compressed macro-tile format.
> + * UBWC decoder block will use the Y_Meta_Plane data together with
> + * Y_UBWC_Plane data to produce loss-less uncompressed 10 bit Y samples.
> + *
> + * UV_Meta_Plane consists of meta information to decode compressed
> + * tile data in UV_UBWC_Plane.
> + * UV_UBWC_Plane consists of UV data in compressed macro-tile format.
> + * UBWC decoder block will use UV_Meta_Plane data together with
> + * UV_UBWC_Plane data to produce loss-less uncompressed 10 bit 2x2
> + * subsampled color difference samples.
> + *
> + * Each tile in Y_UBWC_Plane/UV_UBWC_Plane is independently decodable
> + * and randomly accessible. There is no dependency between tiles.
> + *
> + * <----- Y Meta stride -----> (aligned to 64)
> + * <-------- Width ----------> (aligned to 48)
> + * M M M M M M M M M M M M . . ^ ^
> + * M M M M M M M M M M M M . . | |
> + * M M M M M M M M M M M M . . Height |
> + * M M M M M M M M M M M M . . | Meta_Y_Scanlines (aligned to 16)
> + * M M M M M M M M M M M M . . | |
> + * M M M M M M M M M M M M . . | |
> + * M M M M M M M M M M M M . . | |
> + * M M M M M M M M M M M M . . V |
> + * . . . . . . . . . . . . . . |
> + * . . . . . . . . . . . . . . |
> + * . . . . . . . . . . . . . . -------> Buffer size aligned to 4k
> + * . . . . . . . . . . . . . . V
> + * <--Compressed tile Y stride --> (aligned to 256)
> + * <------- Width * 4/3 ---------> (aligned to 48)
> + * Y* Y* Y* Y* Y* Y* Y* Y* . . . . ^ ^
> + * Y* Y* Y* Y* Y* Y* Y* Y* . . . . | |
> + * Y* Y* Y* Y* Y* Y* Y* Y* . . . . Height |
> + * Y* Y* Y* Y* Y* Y* Y* Y* . . . . | Macro_tile_Y_Scanlines (aligned to 16)
> + * Y* Y* Y* Y* Y* Y* Y* Y* . . . . | |
> + * Y* Y* Y* Y* Y* Y* Y* Y* . . . . | |
> + * Y* Y* Y* Y* Y* Y* Y* Y* . . . . | |
> + * Y* Y* Y* Y* Y* Y* Y* Y* . . . . V |
> + * . . . . . . . . . . . . . . . . |
> + * . . . . . . . . . . . . . . . . |
> + * . . . . . . . . . . . . . . . . -------> Buffer size aligned to 4k
> + * . . . . . . . . . . . . . . . . V
> + * <---- UV Meta stride ----> (aligned to 64)
> + * <----- Width / 2 --------> (aligned to 24)
> + * M M M M M M M M M M M M . . ^ ^
> + * M M M M M M M M M M M M . . | |
> + * M M M M M M M M M M M M . . Height/2 |
> + * M M M M M M M M M M M M . . V M_UV_Scanlines (aligned to 16)
> + * . . . . . . . . . . . . . . |
> + * . . . . . . . . . . . . . . V
> + * . . . . . . . . . . . . . . -------> Buffer size aligned to 4k
> + * <--Compressed tile UV stride--> (aligned to 256)
> + * <------- Width * 4/3 ---------> (aligned to 48)
> + * U* V* U* V* U* V* U* V* . . . . ^
> + * U* V* U* V* U* V* U* V* . . . . |
> + * U* V* U* V* U* V* U* V* . . . . |
> + * U* V* U* V* U* V* U* V* . . . . UV_Scanlines (aligned to 16)
> + * . . . . . . . . . . . . . . . . |
> + * . . . . . . . . . . . . . . . . V
> + * . . . . . . . . . . . . . . . . -------> Buffer size aligned to 4k
> + *
> + * y_stride: width aligned to 256
> + * uv_stride: width aligned to 256
> + * y_scanlines: height aligned to 16
> + * uv_scanlines: height aligned to 16
> + * y_plane: buffer size aligned to 4096
> + * uv_plane: buffer size aligned to 4096
> + * y_meta_stride: width aligned to 64
> + * y_meta_scanlines: height aligned to 16
> + * y_meta_plane: buffer size aligned to 4096
> + * uv_meta_stride: width aligned to 64
> + * uv_meta_scanlines: height aligned to 16
> + * uv_meta_plane: buffer size aligned to 4096
> + *
> + * Total size = align( y_plane + uv_plane +
> + * y_meta_plane + uv_meta_plane, 4096)
> + *
> + * Note: All the alignments are hardware requirements.
> + */
> +static u32 iris_yuv_buffer_size_qc10c(struct iris_inst *inst)
> +{
> + u32 y_plane, uv_plane, y_stride, uv_stride;
> + u32 uv_meta_stride, uv_meta_plane;
> + u32 y_meta_stride, y_meta_plane;
> + struct v4l2_format *f;
> +
> + if (inst->domain == DECODER)
> + f = inst->fmt_dst;
> + else
> + f = inst->fmt_src;
> +
> + y_meta_stride = ALIGN(DIV_ROUND_UP(f->fmt.pix_mp.width, 48),
> + META_STRIDE_ALIGNED);
> + y_meta_plane = y_meta_stride * ALIGN(DIV_ROUND_UP(f->fmt.pix_mp.height, 4),
> + META_SCANLINE_ALIGNED);
> + y_meta_plane = ALIGN(y_meta_plane, PIXELS_4K);
> +
> + y_stride = ALIGN(f->fmt.pix_mp.width * 4 / 3, Y_STRIDE_ALIGN_P010);
> + y_plane = ALIGN(y_stride * ALIGN(f->fmt.pix_mp.height, Y_SCANLINE_ALIGN_QC10C),
> + PIXELS_4K);
> +
> + uv_meta_stride = ALIGN(DIV_ROUND_UP((f->fmt.pix_mp.width + 1) >> 1, 24),
> + META_STRIDE_ALIGNED);
> + uv_meta_plane = uv_meta_stride *
> + ALIGN(DIV_ROUND_UP((f->fmt.pix_mp.height + 1) >> 1, 4),
> + META_SCANLINE_ALIGNED);
> + uv_meta_plane = ALIGN(uv_meta_plane, PIXELS_4K);
> +
> + uv_stride = ALIGN(f->fmt.pix_mp.width * 4 / 3, UV_STRIDE_ALIGN_P010);
> + uv_plane = ALIGN(uv_stride * ALIGN((f->fmt.pix_mp.height + 1) >> 1, UV_SCANLINE_ALIGN),
> + PIXELS_4K);
> +
> + return ALIGN(y_meta_plane + y_plane + uv_meta_plane + uv_plane, PIXELS_4K);
> +}
> +
> static u32 iris_dec_bitstream_buffer_size(struct iris_inst *inst)
> {
> struct platform_inst_caps *caps = inst->core->iris_platform_data->inst_caps;
> @@ -268,10 +454,17 @@ int iris_get_buffer_size(struct iris_inst *inst,
> case BUF_OUTPUT:
> if (inst->fmt_dst->fmt.pix_mp.pixelformat == V4L2_PIX_FMT_QC08C)
> return iris_yuv_buffer_size_qc08c(inst);
> + else if (inst->fmt_dst->fmt.pix_mp.pixelformat == V4L2_PIX_FMT_QC10C)
> + return iris_yuv_buffer_size_qc10c(inst);
> + else if (inst->fmt_dst->fmt.pix_mp.pixelformat == V4L2_PIX_FMT_P010)
> + return iris_yuv_buffer_size_p010(inst);
> else
> return iris_yuv_buffer_size_nv12(inst);
> case BUF_DPB:
> - return iris_yuv_buffer_size_qc08c(inst);
> + if (iris_fmt_is_10bit(inst->fmt_dst->fmt.pix_mp.pixelformat))
> + return iris_yuv_buffer_size_qc10c(inst);
> + else
> + return iris_yuv_buffer_size_qc08c(inst);
> default:
> return 0;
> }
>
> --
> 2.34.1
>
>

Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxxx>

---
bod