Re: [PATCH v3 3/6] media: qcom: iris: gen2: add support for 10bit decoding

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

On 5/21/26 11:44, Vikash Garodia wrote:
> 
> On 5/18/2026 1:02 PM, Neil Armstrong wrote:
>> On 5/13/26 20:50, Vikash Garodia wrote:
>>>
>>> On 5/11/2026 2:50 PM, Neil Armstrong wrote:
>>>> Add the necessary plumbing into the HFi Gen2 to signal the decoder
>>>> the right 10bit pixel format and stride when in compressed mode.
>>>>
>>>> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
>>>> ---
>>>>   .../platform/qcom/iris/iris_hfi_gen2_command.c     | 75 +++++++++++ ++++++++++-
>>>>   .../platform/qcom/iris/iris_hfi_gen2_defines.h     |  1 +
>>>>   drivers/media/platform/qcom/iris/iris_utils.c      |  4 +-
>>>>   3 files changed, 76 insertions(+), 4 deletions(-)
>>>>
>>>> diff --git a/drivers/media/platform/qcom/iris/iris_hfi_gen2_command.c b/drivers/media/platform/qcom/iris/iris_hfi_gen2_command.c
>>>> index 30bfd90d423b..89de8c366836 100644
>>>> --- a/drivers/media/platform/qcom/iris/iris_hfi_gen2_command.c
>>>> +++ b/drivers/media/platform/qcom/iris/iris_hfi_gen2_command.c
>>>> @@ -481,8 +481,20 @@ static int iris_hfi_gen2_set_colorformat(struct iris_inst *inst, u32 plane)
>>>>       if (inst->domain == DECODER) {
>>>>           pixelformat = inst->fmt_dst->fmt.pix_mp.pixelformat;
>>>> -        hfi_colorformat = pixelformat == V4L2_PIX_FMT_NV12 ?
>>>> -            HFI_COLOR_FMT_NV12 : HFI_COLOR_FMT_NV12_UBWC;
>>>> +        switch (pixelformat) {
>>>> +        case V4L2_PIX_FMT_NV12:
>>>> +            hfi_colorformat = HFI_COLOR_FMT_NV12;
>>>> +            break;
>>>> +        case V4L2_PIX_FMT_QC08C:
>>>> +            hfi_colorformat = HFI_COLOR_FMT_NV12_UBWC;
>>>> +            break;
>>>> +        case V4L2_PIX_FMT_P010:
>>>> +            hfi_colorformat = HFI_COLOR_FMT_P010;
>>>> +            break;
>>>> +        case V4L2_PIX_FMT_QC10C:
>>>> +            hfi_colorformat = HFI_COLOR_FMT_TP10_UBWC;
>>>> +            break;
>>>> +        };
>>>
>>> semicolon ?
>>
>> Ack
>>
>>>
>>>>       } else {
>>>>           pixelformat = inst->fmt_src->fmt.pix_mp.pixelformat;
>>>>           hfi_colorformat = pixelformat == V4L2_PIX_FMT_NV12 ?
>>>> @@ -517,7 +529,8 @@ static int iris_hfi_gen2_set_linear_stride_scanline(struct iris_inst *inst, u32
>>>>       stride_uv = stride_y;
>>>>       scanline_uv = scanline_y / 2;
>>>> -    if (pixelformat != V4L2_PIX_FMT_NV12)
>>>> +    if (pixelformat != V4L2_PIX_FMT_NV12 &&
>>>> +        pixelformat != V4L2_PIX_FMT_P010)
>>>>           return 0;
>>>>       payload[0] = stride_y << 16 | scanline_y;
>>>> @@ -532,6 +545,61 @@ static int iris_hfi_gen2_set_linear_stride_scanline(struct iris_inst *inst, u32
>>>>                             sizeof(u64));
>>>>   }
>>>> +static int iris_hfi_gen2_set_ubwc_stride_scanline(struct iris_inst *inst, u32 plane)
>>>> +{
>>>> +    u32 meta_stride_y, meta_scanline_y, meta_stride_uv, meta_scanline_uv;
>>>> +    u32 stride_y, scanline_y, stride_uv, scanline_uv;
>>>> +    u32 port = iris_hfi_gen2_get_port(inst, plane);
>>>> +    u32 pixelformat, width, height;
>>>> +    u32 payload[4];
>>>> +
>>>> +    if (inst->domain != DECODER ||
>>>> +        inst->fmt_src->fmt.pix_mp.pixelformat != V4L2_PIX_FMT_AV1)
>>>
>>> whats the restriction with AV1 here ?
>>
>> This restriction is used in downstream driver and Dikshita reported we shouldn't
>> call HFI_PROP_UBWC_STRIDE_SCANLINE except for AV1.
>>
>> Could you please check if it's necessary ?
>>
> I discussed this with firmware folks. As per them, this interface is effective for AV1, and for others, it might lead to higher size due to host demanded alignment.
> 
> As per firmware team,
> "While the documentation states it is applicable "for AV1 ONLY", sending it for HEVC, VP9, or H.264 will physically work—forcing the UBWC output buffers into the Host's fixed stride layout. However, because older codecs handle resolution changes natively by triggering a standard Port Settings Change (PSC) to reallocate buffers, using this property for them is largely unnecessary and will persist statically, potentially leading to wasted memory due to over-allocated padding"

Thanks a lot for asking, I will leave it as is for now until we have a stride issue we can enable it for other codecs.

Neil

> 
> Regards,
> Vikash