Re: [PATCH v3 00/26] Enable H.264/H.265 encoder support and fixes in iris driver common code

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

Hi,

On 21/08/2025 09:56, Vikash Garodia wrote:
> 
> On 8/21/2025 12:51 PM, Dikshita Agarwal wrote:
>>> The change occurs around Aug 14 2024, So I checked the downstream driver
>>> and I found that fixes the encoding:
>>> ===========================><=================================================
>>> --- a/drivers/media/platform/qcom/iris/iris_vpu_buffer.c
>>> +++ b/drivers/media/platform/qcom/iris/iris_vpu_buffer.c
>>> @@ -863,9 +863,18 @@ static inline
>>>   u32 size_vpss_line_buf(u32 num_vpp_pipes_enc, u32 frame_height_coded,
>>>                         u32 frame_width_coded)
>>>   {
>>> -       return ALIGN(((((((8192) >> 2) << 5) * (num_vpp_pipes_enc)) + 64) +
>>> -                     (((((max_t(u32, (frame_width_coded),
>>> -                                (frame_height_coded)) + 3) >> 2) << 5) +
>>> 256) * 16)), 256);
>>> +       u32 vpss_4tap_top = 0, vpss_4tap_left = 0, vpss_div2_top = 0,
>>> vpss_div2_left = 0, vpss_top_lb = 0, vpss_left_lb = 0, size_left = 0,
>>> size_top = 0;
>>> +
>>> +       vpss_4tap_top = ((((max_t(u32, frame_width_coded,
>>> frame_height_coded) * 2) + 3) >> 2) << 4) + 256;
>>> +       vpss_4tap_left = (((8192 + 3) >> 2) << 5) + 64;
>>> +       vpss_div2_top = (((max_t(u32,frame_width_coded, frame_height_coded)
>>> + 3) >> 2) << 4) + 256;
>>> +       vpss_div2_left = ((((max_t(u32, frame_width_coded,
>>> frame_height_coded)* 2) + 3) >> 2) << 5) + 64;
>>> +       vpss_top_lb = (frame_width_coded + 1) << 3;
>>> +       vpss_left_lb = (frame_height_coded << 3) * num_vpp_pipes_enc;
>>> +       size_left = (vpss_4tap_left + vpss_div2_left) * 2 * num_vpp_pipes_enc;
>>> +       size_top = (vpss_4tap_top + vpss_div2_top) * 2;
>>> +
>>> +       return ALIGN(size_left + size_top + vpss_top_lb + vpss_left_lb,
>>> DMA_ALIGNMENT);
>>>   }
>> Seems this calculation is different for iris3 and iris33, hence you see
>> this issue on SM8650.
>>
>> Updating this calculation in common code will increase the buffer size with
>> from ~400KB to ~2.2 MBs (for 640x480) and even more for higher resolution.
>>
>> @vikash, pls comment if we should update in common code or have this
>> implemented specific for iris33 separately using some ops.
> 
> increasing 1.8 MBs for VGA and assuming it grows further for higher resolution,
> i would recommend to separate it out for line buffer alone.
> 
> Neil,
> We are doing something similar as a preparation for enabling an upcoming SOC,
> maybe let me share the pseudo code offline with you. When you add encode support
> for SM8650, you can raise that change to extend the line buffer calculation for
> iris33.

I don't understand your point, encoding is already enabled with this patchset and
works fine with _old_ firmwares, it just completely fail to encode anything with
the firmware sent on linux-firmware yesterday.

But yes I can provide a fixup patch for vpu33 on top of this serie to be merged in the same
time based on your pseudo code.

Neil

> 
> Regards,
> Vikash