Re: [PATCH RFC 1/7] media: qcom: iris: add QC10C & P010 buffer size calculations

[Neil Armstrong <neil.armstrong@linaro.org>]

On 4/17/26 08:47, Dikshita Agarwal wrote:
> 
> 
> On 4/8/2026 10:13 PM, 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 DPB frames
>> and frames consumed by userspace.
>>
>> Similar to 8bit, the 10bit DPB frames uses QC10C format.
>>
>> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
>> ---
>>   drivers/media/platform/qcom/iris/iris_buffer.c | 81 +++++++++++++++++++++++++-
>>   1 file changed, 80 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/media/platform/qcom/iris/iris_buffer.c b/drivers/media/platform/qcom/iris/iris_buffer.c
>> index 9151f43bc6b9..a0e31bff8f26 100644
>> --- a/drivers/media/platform/qcom/iris/iris_buffer.c
>> +++ b/drivers/media/platform/qcom/iris/iris_buffer.c
>> @@ -15,7 +15,9 @@
>>   #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 UV_SCANLINE_ALIGN 16
>>   #define UV_SCANLINE_ALIGN_QC08C 32
>> @@ -80,6 +82,26 @@ static u32 iris_yuv_buffer_size_nv12(struct iris_inst *inst)
>>   	return ALIGN(y_plane + uv_plane, PIXELS_4K);
>>   }
>>   
>> +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 +226,55 @@ 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:
>> + * Compressed Macro-tile format for TP10.
>> + */
>> +static u32 iris_yuv_buffer_size_qc10c(struct iris_inst *inst)
>> +{
>> +	u32 y_stride, y_buf_height;
>> +	u32 uv_stride, uv_buf_height;
>> +	u32 y_md_stride, y_md_height;
>> +	u32 uv_md_stride, uv_md_height;
>> +	u32 y_data_size, uv_data_size;
>> +	u32 y_md_size, uv_md_size;
>> +	struct v4l2_format *f = NULL;
>> +
>> +	if (inst->domain == DECODER)
>> +		f = inst->fmt_dst;
>> +	else
>> +		f = inst->fmt_src;
>> +
>> +	y_stride = ALIGN(ALIGN(f->fmt.pix_mp.width, 192) * 4 / 3,
>> +			 Y_STRIDE_ALIGN_P010);
> 
> Y_STRIDE_ALIGN_P010 is being used for both P010 and QC10C, lets keep it
> Y_STRIDE_ALIGN_10_BIT ? or something similar ?
> 
>> +	y_buf_height = ALIGN(f->fmt.pix_mp.height, UV_SCANLINE_ALIGN);
> 
> why not call it y_scanlines only?
> 
>> +
>> +	y_data_size = ALIGN(y_stride * y_buf_height, PIXELS_4K);
> 
> s/y_data_size/y_plane ?
> 
>> +
>> +	uv_stride = ALIGN(ALIGN(f->fmt.pix_mp.width, 192) * 4 / 3,
>> +			  UV_STRIDE_ALIGN_P010);
>> +	uv_buf_height = ALIGN((f->fmt.pix_mp.height + 1) / 2,
>> +			      UV_SCANLINE_ALIGN);
> 
> s/uv_buf_height/uv_scanline?
> 
>> +
>> +	uv_data_size = ALIGN(uv_stride * uv_buf_height, PIXELS_4K);
> 
> s/uv_data_size/uv_plane?
> 
> Pls keep all these names consistent with other functions, applies to below
> variables as well.
> 
> 
> Thanks,
> Dikshita
> 
>> +
>> +	y_md_stride = ALIGN(DIV_ROUND_UP(f->fmt.pix_mp.width, 48),
>> +			    META_STRIDE_ALIGNED);
>> +	y_md_height = ALIGN(DIV_ROUND_UP(f->fmt.pix_mp.height, 4),
>> +			    META_SCANLINE_ALIGNED);
>> +
>> +	y_md_size = ALIGN(y_md_stride * y_md_height, PIXELS_4K);
>> +
>> +	uv_md_stride = ALIGN(DIV_ROUND_UP((f->fmt.pix_mp.width + 1) / 2, 24),
>> +			     META_STRIDE_ALIGNED);
>> +	uv_md_height = ALIGN(DIV_ROUND_UP((f->fmt.pix_mp.height + 1) / 2, 4),
>> +			     META_SCANLINE_ALIGNED);
>> +
>> +	uv_md_size = ALIGN(uv_md_stride * uv_md_height, PIXELS_4K);
>> +
>> +	return y_data_size + uv_data_size + y_md_size + uv_md_size;
>> +}
>> +
>>   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 +339,18 @@ 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 (inst->fmt_dst->fmt.pix_mp.pixelformat == V4L2_PIX_FMT_QC10C ||
>> +			    inst->fmt_dst->fmt.pix_mp.pixelformat == V4L2_PIX_FMT_P010)
> 
> Please introduce one API, is_10bit_format and use that here instead.

Ack

> 
> Thanks,
> Dikshita
>> +				return iris_yuv_buffer_size_qc10c(inst);
>> +			else
>> +				return iris_yuv_buffer_size_qc08c(inst);
>>   		default:
>>   			return 0;
>>   		}
>>