Re: [PATCH v2 1/2] media: amphion: Reduce decoding latency for HEVC decoder

["Ming Qian(OSS)" <ming.qian@xxxxxxxxxxx>]

Hi Sebastian,

On 2025/2/26 17:45, Sebastian Fricke wrote:
> [You don't often get email from sebastian.fricke@xxxxxxxxxxxxx. Learn 
> why this is important at https://aka.ms/LearnAboutSenderIdentification ]
>
> Hey Ming,
>
> thank you for the patch!
>
> On 17.01.2025 16:57, Ming Qian wrote:
> > The amphion decoder firmware supports low latency flush mode for
> > HEVC format since v1.9.0, it can help reduce the decoding latency by
> > appending some padding data after every frame, then driver can enable
> > this feature when the display delay 0 is enabled.
>
> I see that you already changed the commit message for this version, but
> I still have a few recommendations for the description:
>
>      The amphion decoder firmware supports a low latency flush mode for
>      the HEVC format since v1.9.0. This feature, which is enabled when
>      the display delay is set to 0, can help to reduce the decoding
>      latency by appending some padding data to every frame.
>
> The rest looks good to me.

Thanks for your feedback, I'm preparing the v3 patch, and it will follow
your advice.

Thanks,
Ming

> Regards,
> Sebastian
>
> > Signed-off-by: Ming Qian <ming.qian@xxxxxxxxxxx>
> > ---
> > v2
> > - Improve commit message
> > - Add firmware version check
> >
> > drivers/media/platform/amphion/vpu_malone.c | 22 ++++++++++++++++++---
> > 1 file changed, 19 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/media/platform/amphion/vpu_malone.c 
> > b/drivers/media/platform/amphion/vpu_malone.c
> > index 5c6b2a841b6f..1d9e10d9bec1 100644
> > --- a/drivers/media/platform/amphion/vpu_malone.c
> > +++ b/drivers/media/platform/amphion/vpu_malone.c
> > @@ -68,6 +68,9 @@
> >
> > #define MALONE_DEC_FMT_RV_MASK                        BIT(21)
> >
> > +#define MALONE_VERSION_MASK                   0xFFFFF
> > +#define MALONE_MIN_VERSION_HEVC_BUFFLUSH      (((1 << 16) | (9 << 8) 
> > | 0) & MALONE_VERSION_MASK)
> > +
> > enum vpu_malone_stream_input_mode {
> >       INVALID_MODE = 0,
> >       FRAME_LVL,
> > @@ -332,6 +335,8 @@ struct vpu_dec_ctrl {
> >       u32 buf_addr[VID_API_NUM_STREAMS];
> > };
> >
> > +static const struct malone_padding_scode *get_padding_scode(u32 type, 
> > u32 fmt);
> > +
> > u32 vpu_malone_get_data_size(void)
> > {
> >       return sizeof(struct vpu_dec_ctrl);
> > @@ -654,9 +659,16 @@ static int vpu_malone_set_params(struct 
> > vpu_shared_addr *shared,
> >               hc->jpg[instance].jpg_mjpeg_interlaced = 0;
> >       }
> >
> > -      hc->codec_param[instance].disp_imm = 
> > params->display_delay_enable ? 1 : 0;
> > -      if (malone_format != MALONE_FMT_AVC)
> > +      if (params->display_delay_enable &&
> > +          get_padding_scode(SCODE_PADDING_BUFFLUSH, 
> > params->codec_format))
> > +              hc->codec_param[instance].disp_imm = 1;
> > +      else
> >               hc->codec_param[instance].disp_imm = 0;
> > +
> > +      if (params->codec_format == V4L2_PIX_FMT_HEVC &&
> > +          (iface->fw_version & MALONE_VERSION_MASK) < 
> > MALONE_MIN_VERSION_HEVC_BUFFLUSH)
> > +              hc->codec_param[instance].disp_imm = 0;
> > +
> >       hc->codec_param[instance].dbglog_enable = 0;
> >       iface->dbglog_desc.level = 0;
> >
> > @@ -1024,6 +1036,7 @@ static const struct malone_padding_scode 
> > padding_scodes[] = {
> >       {SCODE_PADDING_EOS,      V4L2_PIX_FMT_JPEG,        {0x0, 0x0}},
> >       {SCODE_PADDING_BUFFLUSH, V4L2_PIX_FMT_H264,        {0x15010000, 
> > 0x0}},
> >       {SCODE_PADDING_BUFFLUSH, V4L2_PIX_FMT_H264_MVC,    {0x15010000, 
> > 0x0}},
> > +      {SCODE_PADDING_BUFFLUSH, V4L2_PIX_FMT_HEVC,        {0x3e010000, 
> > 0x20}},
> > };
> >
> > static const struct malone_padding_scode padding_scode_dft = {0x0, 0x0};
> > @@ -1058,8 +1071,11 @@ static int vpu_malone_add_padding_scode(struct 
> > vpu_buffer *stream_buffer,
> >       int ret;
> >
> >       ps = get_padding_scode(scode_type, pixelformat);
> > -      if (!ps)
> > +      if (!ps) {
> > +              if (scode_type == SCODE_PADDING_BUFFLUSH)
> > +                      return 0;
> >               return -EINVAL;
> > +      }
> >
> >       wptr = readl(&str_buf->wptr);
> >       if (wptr < stream_buffer->phys || wptr > stream_buffer->phys + 
> > stream_buffer->length)
> > --
> > 2.43.0-rc1