[PATCH v2 06/10] drm/display/dsc: split DSC 1.2 and DSC 1.1 (pre-SCR) parameters

Dmitry Baryshkov dmitry.baryshkov at linaro.org
Wed Mar 8 16:50:02 UTC 2023


On Wed, 8 Mar 2023 at 15:19, Jani Nikula <jani.nikula at linux.intel.com> wrote:
>
> On Wed, 08 Mar 2023, Dmitry Baryshkov <dmitry.baryshkov at linaro.org> wrote:
> > On Wed, 8 Mar 2023 at 12:14, Jani Nikula <jani.nikula at linux.intel.com> wrote:
> >>
> >> On Tue, 07 Mar 2023, Dmitry Baryshkov <dmitry.baryshkov at linaro.org> wrote:
> >> > The array of rc_parameters contains a mixture of parameters from DSC 1.1
> >> > and DSC 1.2 standards. Split these tow configuration arrays in
> >> > preparation to adding more configuration data.
> >> >
> >> > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
> >> > ---
> >> >  drivers/gpu/drm/display/drm_dsc_helper.c  | 127 ++++++++++++++++++----
> >> >  drivers/gpu/drm/i915/display/intel_vdsc.c |  10 +-
> >> >  include/drm/display/drm_dsc_helper.h      |   7 +-
> >> >  3 files changed, 119 insertions(+), 25 deletions(-)
> >> >
> >> > diff --git a/drivers/gpu/drm/display/drm_dsc_helper.c b/drivers/gpu/drm/display/drm_dsc_helper.c
> >> > index acb93d4116e0..35b39f3109c4 100644
> >> > --- a/drivers/gpu/drm/display/drm_dsc_helper.c
> >> > +++ b/drivers/gpu/drm/display/drm_dsc_helper.c
> >> > @@ -324,11 +324,81 @@ struct rc_parameters_data {
> >> >
> >> >  #define DSC_BPP(bpp) ((bpp) << 4)
> >> >
> >> > +static const struct rc_parameters_data rc_parameters_pre_scr[] = {
> >> > +     {
> >> > +             .bpp = DSC_BPP(8), .bpc = 8,
> >> > +             { 512, 12, 6144, 3, 12, 11, 11, {
> >> > +                     { 0, 4, 2 }, { 0, 4, 0 }, { 1, 5, 0 }, { 1, 6, -2 },
> >> > +                     { 3, 7, -4 }, { 3, 7, -6 }, { 3, 7, -8 }, { 3, 8, -8 },
> >> > +                     { 3, 9, -8 }, { 3, 10, -10 }, { 5, 11, -10 }, { 5, 12, -12 },
> >> > +                     { 5, 13, -12 }, { 7, 13, -12 }, { 13, 15, -12 }
> >> > +                     }
> >> > +             }
> >> > +     },
> >> > +     {
> >> > +             .bpp = DSC_BPP(8), .bpc = 10,
> >> > +             { 512, 12, 6144, 7, 16, 15, 15, {
> >> > +                     /*
> >> > +                      * DSC model/pre-SCR-cfg has 8 for range_max_qp[0], however
> >> > +                      * VESA DSC 1.1 Table E-5 sets it to 4.
> >> > +                      */
> >> > +                     { 0, 4, 2 }, { 4, 8, 0 }, { 5, 9, 0 }, { 5, 10, -2 },
> >> > +                     { 7, 11, -4 }, { 7, 11, -6 }, { 7, 11, -8 }, { 7, 12, -8 },
> >> > +                     { 7, 13, -8 }, { 7, 14, -10 }, { 9, 15, -10 }, { 9, 16, -12 },
> >> > +                     { 9, 17, -12 }, { 11, 17, -12 }, { 17, 19, -12 }
> >> > +                     }
> >> > +             }
> >> > +     },
> >> > +     {
> >> > +             .bpp = DSC_BPP(8), .bpc = 12,
> >> > +             { 512, 12, 6144, 11, 20, 19, 19, {
> >> > +                     { 0, 12, 2 }, { 4, 12, 0 }, { 9, 13, 0 }, { 9, 14, -2 },
> >> > +                     { 11, 15, -4 }, { 11, 15, -6 }, { 11, 15, -8 }, { 11, 16, -8 },
> >> > +                     { 11, 17, -8 }, { 11, 18, -10 }, { 13, 19, -10 },
> >> > +                     { 13, 20, -12 }, { 13, 21, -12 }, { 15, 21, -12 },
> >> > +                     { 21, 23, -12 }
> >> > +                     }
> >> > +             }
> >> > +     },
> >> > +     {
> >> > +             .bpp = DSC_BPP(12), .bpc = 8,
> >> > +             { 341, 15, 2048, 3, 12, 11, 11, {
> >> > +                     { 0, 2, 2 }, { 0, 4, 0 }, { 1, 5, 0 }, { 1, 6, -2 },
> >> > +                     { 3, 7, -4 }, { 3, 7, -6 }, { 3, 7, -8 }, { 3, 8, -8 },
> >> > +                     { 3, 9, -8 }, { 3, 10, -10 }, { 5, 11, -10 },
> >> > +                     { 5, 12, -12 }, { 5, 13, -12 }, { 7, 13, -12 }, { 13, 15, -12 }
> >> > +                     }
> >> > +             }
> >> > +     },
> >> > +     {
> >> > +             .bpp = DSC_BPP(12), .bpc = 10,
> >> > +             { 341, 15, 2048, 7, 16, 15, 15, {
> >> > +                     { 0, 2, 2 }, { 2, 5, 0 }, { 3, 7, 0 }, { 4, 8, -2 },
> >> > +                     { 6, 9, -4 }, { 7, 10, -6 }, { 7, 11, -8 }, { 7, 12, -8 },
> >> > +                     { 7, 13, -8 }, { 7, 14, -10 }, { 9, 15, -10 }, { 9, 16, -12 },
> >> > +                     { 9, 17, -12 }, { 11, 17, -12 }, { 17, 19, -12 }
> >> > +                     }
> >> > +             }
> >> > +     },
> >> > +     {
> >> > +             .bpp = DSC_BPP(12), .bpc = 12,
> >> > +             { 341, 15, 2048, 11, 20, 19, 19, {
> >> > +                     { 0, 6, 2 }, { 4, 9, 0 }, { 7, 11, 0 }, { 8, 12, -2 },
> >> > +                     { 10, 13, -4 }, { 11, 14, -6 }, { 11, 15, -8 }, { 11, 16, -8 },
> >> > +                     { 11, 17, -8 }, { 11, 18, -10 }, { 13, 19, -10 },
> >> > +                     { 13, 20, -12 }, { 13, 21, -12 }, { 15, 21, -12 },
> >> > +                     { 21, 23, -12 }
> >> > +                     }
> >> > +             }
> >> > +     },
> >> > +     { /* sentinel */ }
> >> > +};
> >> > +
> >> >  /*
> >> >   * Selected Rate Control Related Parameter Recommended Values
> >> >   * from DSC_v1.11 spec & C Model release: DSC_model_20161212
> >> >   */
> >>
> >> The comment is no longer accurate, is it?
> >
> > Ugh, yes. it is no longer DSC 1.1. I cross-checked, the rc*cfg files
> > are the same between 20161212 and 20210623
> >
> >>
> >> There are various ways to determine the parameters to use. There's even
> >> an application note "VESA DSC v1.2a Guidance on Deriving DSC Rate
> >> Control Parameters" that lists the options. They are all valid and
> >> should "provide visually lossless quality".
> >>
> >> Would it be simplest to always use the C model parameters in the tables
> >> here, referencing the zip file name with date above each table? That
> >> could at least be consistent, and drivers could override parameters
> >> using other methods if they desire. And it would be easiest to review.
> >
> > Do you mean the calculated RC parameters?
>
> No, I simply mean using the values from the .cfg files, and clearly
> stating that in the source. Your reply below implies this is exactly
> what you're doing. What we currently have in intel_vdsc.c isn't clear by
> any means.

Yes, it took me a while to narrow down which entries correspond to
'legacy'/pre-SCR configs.

>
> Moreover, I started checking some of the values against the *specs* and
> those actually differ from the .cfg files. I just want to get rid of the
> ambiguity.

Ugh.

>
> > As I mentioned in another
> > email, it is at least worth investigating. I haven't looked into that,
> > as my primary goal (driven by the forthcoming drm/msm needs) were the
> > .cfg tables. I targeted cleaning up the simplest path to reduce
> > duplication (see [1]). Anyway, with the proposed patches we have the
> > API, which tells nothing about the way it fills out the RC tables.
> > They can be based on top of the cfg files (method 2) or calculated
> > (methods 3, 4).
> >
> > [1] https://patchwork.freedesktop.org/patch/524051/?series=114355&rev=1
> >
> >>
> >> I'm having a hard time finding time to review all this in a timely
> >> fashion. Would be good to try to get other folks to review the rest,
> >> it's really not very i915 specific anyway. In the mean time I think
> >> patches 1-5 are okay to merge via drm-misc.
> >
> > For reference, the tables here are a direct conversion of the rc*cfg
> > files found in the DSC model. If you wish, I can post the program that
> > I used to convert these files into C arrays. Will that help the
> > review?
>
> Probably; it's a bit annoying to cross check as the values aren't in the
> same order.

I pushed my code to
https://git.linaro.org/people/dmitry.baryshkov/dsc_model_process.git/

>
> BR,
> Jani.
>
>
> >
> >>
> >> BR,
> >> Jani.
> >>
> >> > -static const struct rc_parameters_data rc_parameters[] = {
> >> > +static const struct rc_parameters_data rc_parameters_1_2_444[] = {
> >> >       {
> >> >               .bpp = DSC_BPP(6), .bpc = 8,
> >> >               { 768, 15, 6144, 3, 13, 11, 11, {
> >> > @@ -388,22 +458,18 @@ static const struct rc_parameters_data rc_parameters[] = {
> >> >               { 512, 12, 6144, 3, 12, 11, 11, {
> >> >                       { 0, 4, 2 }, { 0, 4, 0 }, { 1, 5, 0 }, { 1, 6, -2 },
> >> >                       { 3, 7, -4 }, { 3, 7, -6 }, { 3, 7, -8 }, { 3, 8, -8 },
> >> > -                     { 3, 9, -8 }, { 3, 10, -10 }, { 5, 11, -10 }, { 5, 12, -12 },
> >> > -                     { 5, 13, -12 }, { 7, 13, -12 }, { 13, 15, -12 }
> >> > +                     { 3, 9, -8 }, { 3, 10, -10 }, { 5, 10, -10 }, { 5, 11, -12 },
> >> > +                     { 5, 11, -12 }, { 9, 12, -12 }, { 12, 13, -12 }
> >> >                       }
> >> >               }
> >> >       },
> >> >       {
> >> >               .bpp = DSC_BPP(8), .bpc = 10,
> >> >               { 512, 12, 6144, 7, 16, 15, 15, {
> >> > -                     /*
> >> > -                      * DSC model/pre-SCR-cfg has 8 for range_max_qp[0], however
> >> > -                      * VESA DSC 1.1 Table E-5 sets it to 4.
> >> > -                      */
> >> > -                     { 0, 4, 2 }, { 4, 8, 0 }, { 5, 9, 0 }, { 5, 10, -2 },
> >> > +                     { 0, 8, 2 }, { 4, 8, 0 }, { 5, 9, 0 }, { 5, 10, -2 },
> >> >                       { 7, 11, -4 }, { 7, 11, -6 }, { 7, 11, -8 }, { 7, 12, -8 },
> >> > -                     { 7, 13, -8 }, { 7, 14, -10 }, { 9, 15, -10 }, { 9, 16, -12 },
> >> > -                     { 9, 17, -12 }, { 11, 17, -12 }, { 17, 19, -12 }
> >> > +                     { 7, 13, -8 }, { 7, 14, -10 }, { 9, 14, -10 }, { 9, 15, -12 },
> >> > +                     { 9, 15, -12 }, { 13, 16, -12 }, { 16, 17, -12 }
> >> >                       }
> >> >               }
> >> >       },
> >> > @@ -412,9 +478,9 @@ static const struct rc_parameters_data rc_parameters[] = {
> >> >               { 512, 12, 6144, 11, 20, 19, 19, {
> >> >                       { 0, 12, 2 }, { 4, 12, 0 }, { 9, 13, 0 }, { 9, 14, -2 },
> >> >                       { 11, 15, -4 }, { 11, 15, -6 }, { 11, 15, -8 }, { 11, 16, -8 },
> >> > -                     { 11, 17, -8 }, { 11, 18, -10 }, { 13, 19, -10 },
> >> > -                     { 13, 20, -12 }, { 13, 21, -12 }, { 15, 21, -12 },
> >> > -                     { 21, 23, -12 }
> >> > +                     { 11, 17, -8 }, { 11, 18, -10 }, { 13, 18, -10 },
> >> > +                     { 13, 19, -12 }, { 13, 19, -12 }, { 17, 20, -12 },
> >> > +                     { 20, 21, -12 }
> >> >                       }
> >> >               }
> >> >       },
> >> > @@ -498,8 +564,8 @@ static const struct rc_parameters_data rc_parameters[] = {
> >> >               { 341, 15, 2048, 3, 12, 11, 11, {
> >> >                       { 0, 2, 2 }, { 0, 4, 0 }, { 1, 5, 0 }, { 1, 6, -2 },
> >> >                       { 3, 7, -4 }, { 3, 7, -6 }, { 3, 7, -8 }, { 3, 8, -8 },
> >> > -                     { 3, 9, -8 }, { 3, 10, -10 }, { 5, 11, -10 },
> >> > -                     { 5, 12, -12 }, { 5, 13, -12 }, { 7, 13, -12 }, { 13, 15, -12 }
> >> > +                     { 3, 8, -8 }, { 3, 9, -10 }, { 5, 9, -10 }, { 5, 9, -12 },
> >> > +                     { 5, 9, -12 }, { 7, 10, -12 }, { 10, 11, -12 }
> >> >                       }
> >> >               }
> >> >       },
> >> > @@ -508,8 +574,8 @@ static const struct rc_parameters_data rc_parameters[] = {
> >> >               { 341, 15, 2048, 7, 16, 15, 15, {
> >> >                       { 0, 2, 2 }, { 2, 5, 0 }, { 3, 7, 0 }, { 4, 8, -2 },
> >> >                       { 6, 9, -4 }, { 7, 10, -6 }, { 7, 11, -8 }, { 7, 12, -8 },
> >> > -                     { 7, 13, -8 }, { 7, 14, -10 }, { 9, 15, -10 }, { 9, 16, -12 },
> >> > -                     { 9, 17, -12 }, { 11, 17, -12 }, { 17, 19, -12 }
> >> > +                     { 7, 12, -8 }, { 7, 13, -10 }, { 9, 13, -10 }, { 9, 13, -12 },
> >> > +                     { 9, 13, -12 }, { 11, 14, -12 }, { 14, 15, -12 }
> >> >                       }
> >> >               }
> >> >       },
> >> > @@ -518,9 +584,9 @@ static const struct rc_parameters_data rc_parameters[] = {
> >> >               { 341, 15, 2048, 11, 20, 19, 19, {
> >> >                       { 0, 6, 2 }, { 4, 9, 0 }, { 7, 11, 0 }, { 8, 12, -2 },
> >> >                       { 10, 13, -4 }, { 11, 14, -6 }, { 11, 15, -8 }, { 11, 16, -8 },
> >> > -                     { 11, 17, -8 }, { 11, 18, -10 }, { 13, 19, -10 },
> >> > -                     { 13, 20, -12 }, { 13, 21, -12 }, { 15, 21, -12 },
> >> > -                     { 21, 23, -12 }
> >> > +                     { 11, 16, -8 }, { 11, 17, -10 }, { 13, 17, -10 },
> >> > +                     { 13, 17, -12 }, { 13, 17, -12 }, { 15, 18, -12 },
> >> > +                     { 18, 19, -12 }
> >> >                       }
> >> >               }
> >> >       },
> >> > @@ -602,7 +668,8 @@ static const struct rc_parameters_data rc_parameters[] = {
> >> >       { /* sentinel */ }
> >> >  };
> >> >
> >> > -static const struct rc_parameters *get_rc_params(u16 dsc_bpp,
> >> > +static const struct rc_parameters *get_rc_params(const struct rc_parameters_data *rc_parameters,
> >> > +                                              u16 dsc_bpp,
> >> >                                                u8 bits_per_component)
> >> >  {
> >> >       int i;
> >> > @@ -622,11 +689,13 @@ static const struct rc_parameters *get_rc_params(u16 dsc_bpp,
> >> >   * function.
> >> >   *
> >> >   * @vdsc_cfg: DSC Configuration data partially filled by driver
> >> > + * @kind: operating mode and standard to follow
> >> >   *
> >> >   * Return: 0 or -error code in case of an error
> >> >   */
> >> > -int drm_dsc_setup_rc_params(struct drm_dsc_config *vdsc_cfg)
> >> > +int drm_dsc_setup_rc_params(struct drm_dsc_config *vdsc_cfg, enum drm_dsc_params_kind kind)
> >> >  {
> >> > +     const struct rc_parameters_data *data;
> >> >       const struct rc_parameters *rc_params;
> >> >       int i;
> >> >
> >> > @@ -634,7 +703,19 @@ int drm_dsc_setup_rc_params(struct drm_dsc_config *vdsc_cfg)
> >> >                        !vdsc_cfg->bits_per_component))
> >> >               return -EINVAL;
> >> >
> >> > -     rc_params = get_rc_params(vdsc_cfg->bits_per_pixel,
> >> > +     switch (kind) {
> >> > +     case DRM_DSC_1_2_444:
> >> > +             data = rc_parameters_1_2_444;
> >> > +             break;
> >> > +     case DRM_DSC_1_1_PRE_SCR:
> >> > +             data = rc_parameters_pre_scr;
> >> > +             break;
> >> > +     default:
> >> > +             return -EINVAL;
> >> > +     }
> >> > +
> >> > +     rc_params = get_rc_params(data,
> >> > +                               vdsc_cfg->bits_per_pixel,
> >> >                                 vdsc_cfg->bits_per_component);
> >> >       if (!rc_params)
> >> >               return -EINVAL;
> >> > diff --git a/drivers/gpu/drm/i915/display/intel_vdsc.c b/drivers/gpu/drm/i915/display/intel_vdsc.c
> >> > index 20a4c2f343fe..a4d1d2ba71bb 100644
> >> > --- a/drivers/gpu/drm/i915/display/intel_vdsc.c
> >> > +++ b/drivers/gpu/drm/i915/display/intel_vdsc.c
> >> > @@ -157,7 +157,15 @@ int intel_dsc_compute_params(struct intel_crtc_state *pipe_config)
> >> >       if (DISPLAY_VER(dev_priv) >= 13) {
> >> >               calculate_rc_params(vdsc_cfg);
> >> >       } else {
> >> > -             ret = drm_dsc_setup_rc_params(vdsc_cfg);
> >> > +             if ((compressed_bpp == 8 ||
> >> > +                  compressed_bpp == 12) &&
> >> > +                 (vdsc_cfg->bits_per_component == 8 ||
> >> > +                  vdsc_cfg->bits_per_component == 10 ||
> >> > +                  vdsc_cfg->bits_per_component == 12))
> >> > +                     ret = drm_dsc_setup_rc_params(vdsc_cfg, DRM_DSC_1_1_PRE_SCR);
> >> > +             else
> >> > +                     ret = drm_dsc_setup_rc_params(vdsc_cfg, DRM_DSC_1_2_444);
> >> > +
> >> >               if (ret)
> >> >                       return ret;
> >> >
> >> > diff --git a/include/drm/display/drm_dsc_helper.h b/include/drm/display/drm_dsc_helper.h
> >> > index 1681791f65a5..c634bb2935d3 100644
> >> > --- a/include/drm/display/drm_dsc_helper.h
> >> > +++ b/include/drm/display/drm_dsc_helper.h
> >> > @@ -10,12 +10,17 @@
> >> >
> >> >  #include <drm/display/drm_dsc.h>
> >> >
> >> > +enum drm_dsc_params_kind {
> >> > +     DRM_DSC_1_2_444,
> >> > +     DRM_DSC_1_1_PRE_SCR, /* legacy params from DSC 1.1 */
> >> > +};
> >> > +
> >> >  void drm_dsc_dp_pps_header_init(struct dp_sdp_header *pps_header);
> >> >  int drm_dsc_dp_rc_buffer_size(u8 rc_buffer_block_size, u8 rc_buffer_size);
> >> >  void drm_dsc_pps_payload_pack(struct drm_dsc_picture_parameter_set *pps_sdp,
> >> >                             const struct drm_dsc_config *dsc_cfg);
> >> >  void drm_dsc_set_rc_buf_thresh(struct drm_dsc_config *vdsc_cfg);
> >> > -int drm_dsc_setup_rc_params(struct drm_dsc_config *vdsc_cfg);
> >> > +int drm_dsc_setup_rc_params(struct drm_dsc_config *vdsc_cfg, enum drm_dsc_params_kind kind);
> >> >  int drm_dsc_compute_rc_parameters(struct drm_dsc_config *vdsc_cfg);
> >> >
> >> >  #endif /* _DRM_DSC_HELPER_H_ */
> >>
> >> --
> >> Jani Nikula, Intel Open Source Graphics Center
>
> --
> Jani Nikula, Intel Open Source Graphics Center



-- 
With best wishes
Dmitry


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